diff --git a/bundles/sirix-core/src/main/java/io/sirix/BinaryEncodingVersion.java b/bundles/sirix-core/src/main/java/io/sirix/BinaryEncodingVersion.java index 8b73e88ff..59886c733 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/BinaryEncodingVersion.java +++ b/bundles/sirix-core/src/main/java/io/sirix/BinaryEncodingVersion.java @@ -36,8 +36,9 @@ public enum BinaryEncodingVersion { /** - * Zero-copy format: slot offsets array + raw slotMemory blob. Enables direct buffer slice as page - * storage without copying. + * Unified page format: Header(32B) + Bitmap(128B) + Directory(8KB) + Heap. + * FlyweightNode records bind directly to page memory for zero-copy reads. + * Non-FlyweightNode records are serialized to the heap at commit time. */ V0((byte) 0); diff --git a/bundles/sirix-core/src/main/java/io/sirix/access/Databases.java b/bundles/sirix-core/src/main/java/io/sirix/access/Databases.java index 707ace5da..f16441a16 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/access/Databases.java +++ b/bundles/sirix-core/src/main/java/io/sirix/access/Databases.java @@ -36,7 +36,6 @@ * @author Sebastian Graf, University of Konstanz */ public final class Databases { - /** * Private constructor to prevent instantiation. */ @@ -596,4 +595,5 @@ public static synchronized void reinitializeBufferManagerForTesting(long recordP logger.info("BufferManager reinitialized for testing"); } + } diff --git a/bundles/sirix-core/src/main/java/io/sirix/access/ResourceStoreImpl.java b/bundles/sirix-core/src/main/java/io/sirix/access/ResourceStoreImpl.java index ccd08ee27..63f7222dc 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/access/ResourceStoreImpl.java +++ b/bundles/sirix-core/src/main/java/io/sirix/access/ResourceStoreImpl.java @@ -60,7 +60,10 @@ public R getOpenResourceSession(final Path resourceFile) { @Override public void close() { - resourceSessions.forEach((_, resourceSession) -> resourceSession.close()); + resourceSessions.forEach((resourceFile, resourceSession) -> { + resourceSession.close(); + allResourceSessions.removeObject(resourceFile, resourceSession); + }); resourceSessions.clear(); } diff --git a/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/AbstractNodeHashing.java b/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/AbstractNodeHashing.java index 3f6adab01..e1b6c005c 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/AbstractNodeHashing.java +++ b/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/AbstractNodeHashing.java @@ -70,13 +70,25 @@ public void setAutoCommit(final boolean value) { /** * Adapting the structure with a hash for all ancestors only with insert. + * Uses the current cursor position as the start node. * * @throws SirixIOException if an I/O error occurs */ public void adaptHashesWithAdd() { + adaptHashesWithAdd(nodeReadOnlyTrx.getNodeKey()); + } + + /** + * Adapting the structure with a hash for all ancestors only with insert. + * Accepts the start node key directly, avoiding a moveTo to position the cursor. + * + * @param startNodeKey the node key to start hashing from + * @throws SirixIOException if an I/O error occurs + */ + public void adaptHashesWithAdd(final long startNodeKey) { if (!bulkInsert || autoCommit) { switch (hashType) { - case ROLLING -> rollingAdd(); + case ROLLING -> rollingAdd(startNodeKey); case POSTORDER -> postorderAdd(); case NONE -> { } @@ -190,7 +202,8 @@ private void postorderAdd() { protected abstract StructNode getStructuralNode(); private void persistNode(final Node node) { - storageEngineWriter.updateRecordSlot(node, IndexType.DOCUMENT, -1); + // Ensure the mutated node is stored in the TIL's modified page. + storageEngineWriter.persistRecord(node, IndexType.DOCUMENT, -1); } /** @@ -290,10 +303,14 @@ private static void setRemoveDescendants(final long startDescendantCount, final * * @throws SirixIOException if an I/O error occurs */ - private void rollingAdd() { - // start with hash to add - final Node startNode = storageEngineWriter.prepareRecordForModification(nodeReadOnlyTrx.getNodeKey(), IndexType.DOCUMENT, -1); - final long startNodeKey = startNode.getNodeKey(); + private void rollingAdd(final long startNodeKey) { + // Position cursor on start node — needed for getStructuralNode().getDescendantCount() + // and to restore position at end. The caller eliminated the moveTo before adaptForInsert + // which is the bigger win (adaptForInsert is called unconditionally; rollingAdd only + // when hashing is enabled). + nodeReadOnlyTrx.moveTo(startNodeKey); + // start with hash to add — startNodeKey passed directly + final Node startNode = storageEngineWriter.prepareRecordForModification(startNodeKey, IndexType.DOCUMENT, -1); // Capture all needed values from startNode before any subsequent prepareRecordForModification // calls, which may return the same write-path singleton and overwrite startNode's fields. final long startParentKey = startNode.getParentKey(); diff --git a/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/AbstractNodeReadOnlyTrx.java b/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/AbstractNodeReadOnlyTrx.java index 855f7ec3d..42347158f 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/AbstractNodeReadOnlyTrx.java +++ b/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/AbstractNodeReadOnlyTrx.java @@ -1,28 +1,30 @@ package io.sirix.access.trx.node; -import io.brackit.query.atomic.QNm; import io.sirix.access.ResourceConfiguration; import io.sirix.access.User; import io.sirix.access.trx.page.NodeStorageEngineReader; -import io.sirix.api.*; +import io.sirix.api.ItemList; +import io.sirix.api.NodeCursor; +import io.sirix.api.NodeReadOnlyTrx; +import io.sirix.api.NodeTrx; +import io.sirix.api.ResourceSession; +import io.sirix.api.StorageEngineReader; +import io.sirix.api.StorageEngineWriter; import io.sirix.cache.PageGuard; import io.sirix.exception.SirixIOException; import io.sirix.index.IndexType; +import io.sirix.node.DeltaVarIntCodec; import io.sirix.node.NodeKind; import io.sirix.node.SirixDeweyID; import io.sirix.node.interfaces.DataRecord; import io.sirix.node.interfaces.NameNode; import io.sirix.node.interfaces.StructNode; import io.sirix.node.interfaces.immutable.ImmutableNode; -import io.sirix.node.layout.FixedSlotRecordMaterializer; -import io.sirix.node.layout.FixedSlotRecordProjector; -import io.sirix.node.layout.NodeKindLayout; -import io.sirix.node.layout.SlotLayoutAccessors; -import io.sirix.node.layout.StructuralField; import io.sirix.node.BytesIn; import io.sirix.node.MemorySegmentBytesIn; import io.sirix.node.json.ArrayNode; import io.sirix.node.json.BooleanNode; +import io.sirix.node.json.JsonDocumentRootNode; import io.sirix.node.json.NumberNode; import io.sirix.node.json.ObjectBooleanNode; import io.sirix.node.json.ObjectKeyNode; @@ -30,9 +32,10 @@ import io.sirix.node.json.ObjectNullNode; import io.sirix.node.json.ObjectNumberNode; import io.sirix.node.json.ObjectStringNode; -import io.sirix.node.json.JsonDocumentRootNode; import io.sirix.node.json.NullNode; import io.sirix.node.json.StringNode; +import io.sirix.node.interfaces.FlyweightNode; +import io.sirix.node.interfaces.Node; import io.sirix.node.xml.AttributeNode; import io.sirix.node.xml.CommentNode; import io.sirix.node.xml.ElementNode; @@ -41,7 +44,9 @@ import io.sirix.node.xml.TextNode; import io.sirix.node.xml.XmlDocumentRootNode; import io.sirix.page.KeyValueLeafPage; +import io.sirix.page.PageLayout; import io.sirix.service.xml.xpath.AtomicValue; +import io.sirix.settings.Constants; import io.sirix.settings.Fixed; import io.sirix.utils.NamePageHash; import org.checkerframework.checker.index.qual.NonNegative; @@ -62,7 +67,7 @@ * @param the type of node cursor */ public abstract class AbstractNodeReadOnlyTrx - implements InternalNodeReadOnlyTrx { + implements InternalNodeReadOnlyTrx, NodeCursor, NodeReadOnlyTrx { /** * ID of transaction. @@ -75,12 +80,12 @@ public abstract class AbstractNodeReadOnlyTrx resourceSession; @@ -93,81 +98,115 @@ public abstract class AbstractNodeReadOnlyTrx itemList; - - // ==================== CURSOR SLOT STATE ==================== - + + // ==================== FLYWEIGHT CURSOR STATE ==================== + // These fields enable zero-allocation navigation by reading directly from MemorySegment + + /** + * The raw MemorySegment containing the current node's serialized data. + * When in flyweight mode, getters read directly from this segment. + */ + private MemorySegment currentSlot; + /** * The current node's key (used for delta decoding). */ private long currentNodeKey; - + /** * The current node's kind. */ private NodeKind currentNodeKind; - + + /** + * The current node's DeweyID bytes (may be null if DeweyIDs not stored). + */ + private byte[] currentDeweyId; + /** - * Page guard protecting the current page from eviction. MUST be released when moving to a different - * node or closing the transaction. + * Page guard protecting the current page from eviction. + * MUST be released when moving to a different node or closing the transaction. */ private PageGuard currentPageGuard; - + /** - * The page key of the currently held page guard. Used to detect same-page moves and avoid guard - * release/reacquire overhead. + * The page key of the currently held page guard. + * Used to detect same-page moves and avoid guard release/reacquire overhead. */ private long currentPageKey = -1; - + /** - * The current page reference (same page as currentPageGuard). Cached to avoid re-lookup when moving - * within the same page. + * The current page reference (same page as currentPageGuard). + * Cached to avoid re-lookup when moving within the same page. */ private KeyValueLeafPage currentPage; - + /** - * Slot offset of the current singleton node in {@link #currentPage}. + * Reusable BytesIn instance for reading node data. + * Avoids allocation on every moveTo() call. */ - private int currentSlotOffset = -1; - + private final MemorySegmentBytesIn reusableBytesIn = new MemorySegmentBytesIn(MemorySegment.NULL); + /** - * Reusable BytesIn instance for reading node data. Avoids allocation on every moveTo() call. + * Whether the transaction is in flyweight mode (reading from currentSlot). + * When false, falls back to using currentNode object. */ - private final MemorySegmentBytesIn reusableBytesIn = new MemorySegmentBytesIn(MemorySegment.NULL); - + private boolean flyweightMode = true; + /** - * Resource configuration cached for hash type checks. + * Preallocated array for caching field offsets within currentSlot. + * Indices are defined by FIELD_* constants. + * This avoids re-parsing varints on each getter call. */ - protected final ResourceConfiguration resourceConfig; - + protected final int[] cachedFieldOffsets = new int[16]; + + // Field offset indices for cachedFieldOffsets array + protected static final int FIELD_PARENT_KEY = 0; + protected static final int FIELD_PREV_REVISION = 1; + protected static final int FIELD_LAST_MOD_REVISION = 2; + protected static final int FIELD_RIGHT_SIBLING_KEY = 3; + protected static final int FIELD_LEFT_SIBLING_KEY = 4; + protected static final int FIELD_FIRST_CHILD_KEY = 5; + protected static final int FIELD_LAST_CHILD_KEY = 6; + protected static final int FIELD_CHILD_COUNT = 7; + protected static final int FIELD_DESCENDANT_COUNT = 8; + protected static final int FIELD_HASH = 9; + protected static final int FIELD_NAME_KEY = 10; + protected static final int FIELD_PATH_NODE_KEY = 11; + protected static final int FIELD_VALUE = 12; + protected static final int FIELD_END = 13; // End marker for offset validation + /** - * Whether singleton-mode hot-path rebinding is enabled for this resource. JSON and XML resources - * use singleton rebinding. + * Resource configuration cached for hash type checks. */ - private final boolean singletonOptimizedResource; + protected final ResourceConfiguration resourceConfig; /** - * Whether the current resource is an XML resource. + * Cached {@link NodeStorageEngineReader} resolved once from {@link #storageEngineReader}. + * For read-only transactions, this is the reader itself. + * For write transactions, this is the delegate reader extracted from the writer. + * Used by {@link #moveTo(long)} to enable singleton mode without per-call instanceof checks. */ - private final boolean xmlSingletonResource; + private NodeStorageEngineReader cachedNodeReader; /** - * Tracks if Dewey bytes are already bound for the current singleton. Deferred binding avoids a - * byte[] allocation on every moveTo. + * Cached {@link StorageEngineWriter} reference, non-null only for write transactions. + * Used by {@link #moveToSingletonSlowPath} to resolve TIL modified pages. */ - private boolean singletonDeweyBound = true; + private StorageEngineWriter cachedWriter; /** * Constructor. * - * @param trxId the transaction ID + * @param trxId the transaction ID * @param pageReadTransaction the underlying read-only page transaction - * @param documentNode the document root node - * @param resourceSession The resource session for the current transaction - * @param itemList Read-transaction-exclusive item list. + * @param documentNode the document root node + * @param resourceSession The resource manager for the current transaction + * @param itemList Read-transaction-exclusive item list. */ - protected AbstractNodeReadOnlyTrx(final @NonNegative int trxId, - final @NonNull StorageEngineReader pageReadTransaction, final @NonNull N documentNode, - final InternalResourceSession resourceSession, final ItemList itemList) { + protected AbstractNodeReadOnlyTrx(final @NonNegative int trxId, final @NonNull StorageEngineReader pageReadTransaction, + final @NonNull N documentNode, final InternalResourceSession resourceSession, + final ItemList itemList) { this.itemList = itemList; this.resourceSession = requireNonNull(resourceSession); this.id = trxId; @@ -175,12 +214,13 @@ protected AbstractNodeReadOnlyTrx(final @NonNegative int trxId, this.currentNode = requireNonNull(documentNode); this.isClosed = false; this.resourceConfig = resourceSession.getResourceConfig(); + this.cachedNodeReader = resolveNodeReader(pageReadTransaction); + this.cachedWriter = (pageReadTransaction instanceof StorageEngineWriter w) ? w : null; - // Initialize cursor state from document node. + // Initialize flyweight state from document node this.currentNodeKey = documentNode.getNodeKey(); this.currentNodeKind = documentNode.getKind(); - this.xmlSingletonResource = documentNode.getKind() == NodeKind.XML_DOCUMENT; - this.singletonOptimizedResource = documentNode.getKind() == NodeKind.JSON_DOCUMENT || xmlSingletonResource; + this.flyweightMode = false; // Start with object mode for document node } @Override @@ -190,16 +230,22 @@ public N getCurrentNode() { } // When in singleton mode, create a snapshot (deep copy) of the singleton. - if (singletonMode && currentSingleton != null) { + // Snapshot semantics are required because singleton instances are reused across moveTo calls. + if (SINGLETON_ENABLED && singletonMode && currentSingleton != null) { currentNode = createSingletonSnapshot(); + return currentNode; + } + + if (FLYWEIGHT_ENABLED && flyweightMode && currentSlot != null) { + currentNode = deserializeToSnapshot(); } return currentNode; } - + /** - * Create a deep copy snapshot of the current singleton node. The snapshot is a new object with all - * values copied, safe to hold across cursor moves. + * Create a deep copy snapshot of the current singleton node. + * The snapshot is a new object with all values copied, safe to hold across cursor moves. * * @return a snapshot of the current singleton */ @@ -218,24 +264,40 @@ private N createSingletonSnapshot() { case OBJECT_BOOLEAN_VALUE -> (N) ((ObjectBooleanNode) currentSingleton).toSnapshot(); case OBJECT_NULL_VALUE -> (N) ((ObjectNullNode) currentSingleton).toSnapshot(); case JSON_DOCUMENT -> (N) ((JsonDocumentRootNode) currentSingleton).toSnapshot(); - case XML_DOCUMENT -> (N) ((XmlDocumentRootNode) currentSingleton).toSnapshot(); case ELEMENT -> (N) ((ElementNode) currentSingleton).toSnapshot(); case ATTRIBUTE -> (N) ((AttributeNode) currentSingleton).toSnapshot(); - case NAMESPACE -> (N) ((NamespaceNode) currentSingleton).toSnapshot(); case TEXT -> (N) ((TextNode) currentSingleton).toSnapshot(); case COMMENT -> (N) ((CommentNode) currentSingleton).toSnapshot(); case PROCESSING_INSTRUCTION -> (N) ((PINode) currentSingleton).toSnapshot(); + case NAMESPACE -> (N) ((NamespaceNode) currentSingleton).toSnapshot(); + case XML_DOCUMENT -> (N) ((XmlDocumentRootNode) currentSingleton).toSnapshot(); default -> throw new IllegalStateException("Unexpected singleton kind: " + currentNodeKind); }; } + + /** + * Deserialize the current slot to a node object (snapshot). + * This is the escape hatch for code that needs a stable node reference. + * Called by getCurrentNode() when in flyweight mode. + * + * @return the deserialized node + */ + @SuppressWarnings("unchecked") + protected N deserializeToSnapshot() { + // Use the same deserialization as normal read path + var bytesIn = new MemorySegmentBytesIn(currentSlot); + var record = resourceConfig.recordPersister.deserialize(bytesIn, currentNodeKey, currentDeweyId, resourceConfig); + return (N) record; + } @Override public void setCurrentNode(final @Nullable N currentNode) { assertNotClosed(); this.currentNode = currentNode; - + if (currentNode != null) { - // Disable singleton mode and use the provided node object. + // Disable flyweight and singleton modes - use the provided node object + this.flyweightMode = false; this.singletonMode = false; this.currentSingleton = null; this.currentNodeKey = currentNode.getNodeKey(); @@ -263,7 +325,7 @@ public Optional getUser() { @Override public boolean moveToPrevious() { assertNotClosed(); - // Use cursor getters to avoid unnecessary materialization. + // Use flyweight getters to avoid node materialization if (hasLeftSibling()) { // Left sibling node. boolean leftSiblMove = moveTo(getLeftSiblingKey()); @@ -281,7 +343,7 @@ public boolean moveToPrevious() { public NodeKind getLeftSiblingKind() { assertNotClosed(); if (hasLeftSibling()) { - // Save current position using cursor-compatible getters. + // Save current position using flyweight-compatible getters final long savedNodeKey = getNodeKey(); moveToLeftSibling(); final NodeKind leftSiblingKind = getKind(); @@ -294,16 +356,19 @@ public NodeKind getLeftSiblingKind() { @Override public long getLeftSiblingKey() { assertNotClosed(); - if (singletonMode && currentSingleton instanceof StructNode sn) { + if (SINGLETON_ENABLED && singletonMode && currentSingleton instanceof StructNode sn) { return sn.getLeftSiblingKey(); } + if (FLYWEIGHT_ENABLED && flyweightMode && cachedFieldOffsets[FIELD_LEFT_SIBLING_KEY] >= 0) { + return DeltaVarIntCodec.decodeDeltaFromSegment(currentSlot, cachedFieldOffsets[FIELD_LEFT_SIBLING_KEY], currentNodeKey); + } return getStructuralNode().getLeftSiblingKey(); } @Override public boolean hasLeftSibling() { assertNotClosed(); - if (singletonMode) { + if ((SINGLETON_ENABLED && singletonMode) || (FLYWEIGHT_ENABLED && flyweightMode)) { return getLeftSiblingKey() != Fixed.NULL_NODE_KEY.getStandardProperty(); } return getStructuralNode().hasLeftSibling(); @@ -312,7 +377,7 @@ public boolean hasLeftSibling() { @Override public boolean moveToLeftSibling() { assertNotClosed(); - // Use cursor getter and avoid unnecessary materialization. + // Use flyweight getter if available to avoid node materialization if (!hasLeftSibling()) { return false; } @@ -334,17 +399,7 @@ public String nameForKey(final int key) { @Override public long getPathNodeKey() { assertNotClosed(); - final NodeKind kind = getKind(); - if (kind == NodeKind.XML_DOCUMENT || kind == NodeKind.JSON_DOCUMENT) { - return 0; - } - - final ImmutableNode node; - if (singletonMode && currentSingleton != null) { - node = currentSingleton; - } else { - node = getCurrentNode(); - } + final ImmutableNode node = getCurrentNode(); if (node instanceof NameNode) { return ((NameNode) node).getPathNodeKey(); } @@ -354,6 +409,9 @@ public long getPathNodeKey() { if (node instanceof ArrayNode arrayNode) { return arrayNode.getPathNodeKey(); } + if (node.getKind() == NodeKind.XML_DOCUMENT || node.getKind() == NodeKind.JSON_DOCUMENT) { + return 0; + } return -1; } @@ -390,7 +448,7 @@ public boolean moveToParent() { @Override public boolean moveToFirstChild() { assertNotClosed(); - // Use cursor getter and avoid unnecessary materialization. + // Use flyweight getter if available to avoid node materialization if (!hasFirstChild()) { return false; } @@ -406,20 +464,39 @@ public boolean moveTo(final long nodeKey) { return moveToItemList(nodeKey); } - if (singletonOptimizedResource && storageEngineReader instanceof NodeStorageEngineReader reader) { - return moveToSingleton(nodeKey, reader); + // Use singleton mode for READ-ONLY transactions (cachedWriter == null). + // Write transactions fall through to moveToLegacy for now — the writer's overridden + // getRecord() provides TIL-aware page resolution that moveToSingleton needs. + if (SINGLETON_ENABLED && cachedNodeReader != null && cachedWriter == null) { + return moveToSingleton(nodeKey, cachedNodeReader); + } + + // Write path: use moveToSingletonWrite for TIL-aware singleton mode + if (SINGLETON_ENABLED && cachedWriter != null && cachedNodeReader != null) { + return moveToSingletonWrite(nodeKey, cachedNodeReader, cachedWriter); } - // Fallback to traditional object mode. + // Fallback to traditional object mode return moveToLegacy(nodeKey); } - + + /** + * Toggle for flyweight mode. Set to true to enable zero-allocation optimization. + * Note: Flyweight mode reads directly from MemorySegment but has varint parsing overhead. + */ + private static final boolean FLYWEIGHT_ENABLED = false; + + /** + * Toggle for singleton mode. Set to true to enable singleton node reuse. + * Singleton mode uses mutable singleton nodes that are repopulated on each moveTo(). + * When combined with cache checking, uses cached records when available. + */ + private static final boolean SINGLETON_ENABLED = true; + // ==================== SINGLETON NODE INSTANCES ==================== // These mutable singleton nodes are reused across moveTo() operations. - // Each supported JSON/XML node type has a dedicated singleton instance. - - private static final QNm EMPTY_QNM = new QNm(""); - + // Each JSON node type has a dedicated singleton instance. + private ObjectNode singletonObject; private ArrayNode singletonArray; private ObjectKeyNode singletonObjectKey; @@ -431,73 +508,146 @@ public boolean moveTo(final long nodeKey) { private ObjectNumberNode singletonObjectNumber; private ObjectBooleanNode singletonObjectBoolean; private ObjectNullNode singletonObjectNull; - private JsonDocumentRootNode singletonJsonDocumentRoot; - private XmlDocumentRootNode singletonXmlDocumentRoot; + private JsonDocumentRootNode singletonJsonDocRoot; private ElementNode singletonElement; private AttributeNode singletonAttribute; - private NamespaceNode singletonNamespace; private TextNode singletonText; private CommentNode singletonComment; private PINode singletonPI; - + private NamespaceNode singletonNamespace; + private XmlDocumentRootNode singletonXmlDocRoot; + /** * Whether currently in singleton mode (using singleton nodes). */ private boolean singletonMode = false; - + /** * The current singleton node (set when in singletonMode). */ private ImmutableNode currentSingleton; - /** - * Move to a node using singleton mode (zero allocation). Repopulates a mutable singleton instance - * from serialized data. NO allocation happens here - only when getCurrentNode() is called. + * Array-based singleton lookup indexed by NodeKind.getId(). + * Replaces the 19-case switch in getSingletonForKind with O(1) array access. + * Lazily populated on first access per kind. Max NodeKind ID is 55. + */ + private final ImmutableNode[] singletonByKindId = new ImmutableNode[56]; + + /** + * Move to a node using flyweight mode (zero allocation). + * Reads directly from MemorySegment without creating node objects. + * + * @param nodeKey the node key to move to + * @param reader the storage engine reader + * @return true if the move was successful + */ + private boolean moveToFlyweight(final long nodeKey, final NodeStorageEngineReader reader) { + // Try singleton mode first (preferred for JSON nodes) + if (SINGLETON_ENABLED) { + return moveToSingleton(nodeKey, reader); + } + + if (!FLYWEIGHT_ENABLED) { + return moveToLegacy(nodeKey); + } + + // Lookup slot directly without deserializing + // NOTE: We acquire the new guard BEFORE releasing the old one to ensure + // the transaction state remains valid if the lookup fails. + var slotLocation = reader.lookupSlotWithGuard(nodeKey, IndexType.DOCUMENT, -1); + if (slotLocation == null) { + // Node not found - keep the current position unchanged + return false; + } + + // Read node kind from first byte + MemorySegment data = slotLocation.data(); + byte kindByte = data.get(java.lang.foreign.ValueLayout.JAVA_BYTE, 0); + NodeKind kind = NodeKind.getKind(kindByte); + + // Check for deleted node + if (kind == NodeKind.DELETE) { + // Release the newly acquired guard, keep current position unchanged + slotLocation.guard().close(); + return false; + } + + // Move succeeded - now release the previous page guard + releaseCurrentPageGuard(); + + // Update flyweight state (NO ALLOCATION) + this.currentSlot = data; + this.currentNodeKey = nodeKey; + this.currentNodeKind = kind; + this.currentDeweyId = slotLocation.page().getDeweyIdAsByteArray(slotLocation.offset()); + this.currentPageGuard = slotLocation.guard(); + this.flyweightMode = true; + this.currentNode = null; // Invalidate cached node object + + // Parse and cache field offsets for fast getter access + parseFieldOffsets(); + + return true; + } + + /** + * Move to a node using singleton mode (zero allocation). + * Repopulates a mutable singleton instance from serialized data. + * NO allocation happens here - only when getCurrentNode() is called. * * @param nodeKey the node key to move to - * @param reader the storage engine reader + * @param reader the storage engine reader * @return true if the move was successful */ private boolean moveToSingleton(final long nodeKey, final NodeStorageEngineReader reader) { - // Calculate target page key to check for same-page access - final long targetPageKey = reader.pageKey(nodeKey, IndexType.DOCUMENT); - final int slotOffset = StorageEngineReader.recordPageOffset(nodeKey); + // Inline pageKey: all index types use exponent 10, avoids assertNotClosed + switch overhead + final long targetPageKey = nodeKey >> Constants.NDP_NODE_COUNT_EXPONENT; + final int slotOffset = (int) (nodeKey & ((1 << Constants.NDP_NODE_COUNT_EXPONENT) - 1)); + MemorySegment data; KeyValueLeafPage page; // OPTIMIZATION: Check if we're moving within the same page if (currentPageKey == targetPageKey && currentPage != null && !currentPage.isClosed()) { // Same page! Skip guard management entirely page = currentPage; + + // Check records[] first: Java objects are authoritative during write transactions + // (modifications via prepareRecordForModification are NOT synced back to page heap) + final DataRecord fromRecords = page.getRecord(slotOffset); + if (fromRecords != null) { + if (fromRecords.getKind() == NodeKind.DELETE) { + return false; + } + @SuppressWarnings("unchecked") + final N node = (N) fromRecords; + this.currentNode = node; + this.currentNodeKind = (NodeKind) fromRecords.getKind(); + this.currentNodeKey = nodeKey; + this.currentSingleton = null; + this.singletonMode = false; + this.flyweightMode = false; + return true; + } + + data = page.getSlot(slotOffset); + if (data == null) { + // Slot not found on current page - try overflow or fail + return moveToSingletonSlowPath(nodeKey, reader); + } } else { // Different page - use the slow path with guard management return moveToSingletonSlowPath(nodeKey, reader); } - // Read slot metadata without allocating an asSlice - final int dataLength = page.getSlotDataLength(slotOffset); - if (dataLength < 0) { - // Slot not found on current page - try overflow or fail - return moveToSingletonSlowPath(nodeKey, reader); - } - final MemorySegment slotMemory = page.getSlotMemory(); - final long baseOffset = page.getSlotDataOffset(slotOffset); + // Read node kind from first byte + byte kindByte = data.get(java.lang.foreign.ValueLayout.JAVA_BYTE, 0); + NodeKind kind = NodeKind.getKind(kindByte); - final boolean fixedSlotFormat = page.isFixedSlotFormat(slotOffset); - final NodeKind kind; - if (fixedSlotFormat) { - kind = page.getFixedSlotNodeKind(slotOffset); - if (kind == null) { - return moveToLegacy(nodeKey); - } - } else { - // Read node kind from first byte (zero-copy: read directly from slotMemory). - final byte kindByte = slotMemory.get(java.lang.foreign.ValueLayout.JAVA_BYTE, baseOffset); - kind = NodeKind.getKind(kindByte); - if (kind == NodeKind.DELETE) { - return false; - } + // Check for deleted node + if (kind == NodeKind.DELETE) { + return false; } // Get singleton instance for this node type @@ -507,598 +657,394 @@ private boolean moveToSingleton(final long nodeKey, final NodeStorageEngineReade return moveToLegacy(nodeKey); } - // Populate singleton from slot bytes (no allocation on the singleton path). - // Note: no guard management needed, we're on the same page. - // Dewey bytes are bound lazily on demand to avoid byte[] allocation per moveTo. - if (fixedSlotFormat) { - if (!populateSingletonFromFixedSlot(singleton, kind, slotMemory, baseOffset, dataLength, nodeKey, null, page)) { - return moveToLegacy(nodeKey); + // Check if this is a flyweight record in slotted page + final boolean isFlyweightSlot = page.getSlottedPage() != null && page.getSlotNodeKindId(slotOffset) > 0 + && singleton instanceof FlyweightNode; + if (isFlyweightSlot) { + final FlyweightNode fn = (FlyweightNode) singleton; + // Bind flyweight directly to slotted page (zero-copy, no legacy parsing) + final int heapOffset = PageLayout.getDirHeapOffset(page.getSlottedPage(), slotOffset); + final long recordBase = PageLayout.heapAbsoluteOffset(heapOffset); + fn.bind(page.getSlottedPage(), recordBase, nodeKey, slotOffset); + // Propagate FSST symbol table for compressed string nodes + propagateFsstToFlyweight(fn, page); + // Propagate DeweyID from page to flyweight node (stored inline after record data). + // setDeweyIDBytes stores raw bytes lazily — no SirixDeweyID parsing until getDeweyID() called. + // MUST always set (even null) to clear stale DeweyID from previous singleton reuse. + if (resourceConfig.areDeweyIDsStored && fn instanceof Node node) { + node.setDeweyIDBytes(page.getDeweyIdAsByteArray(slotOffset)); } } else { - reusableBytesIn.reset(slotMemory, baseOffset + 1); - populateSingleton(singleton, reusableBytesIn, nodeKey, null, kind, page); + // Legacy format: populate from serialized data (NO ALLOCATION) + // Reuse BytesIn instance - just reset to new segment and offset (skip kind byte) + reusableBytesIn.reset(data, 1); + // Only fetch DeweyID if actually stored (avoids byte[] allocation) + byte[] deweyId = resourceConfig.areDeweyIDsStored ? page.getDeweyIdAsByteArray(slotOffset) : null; + populateSingleton(singleton, reusableBytesIn, nodeKey, deweyId, kind, page); } // Update state - we're in singleton mode now (page guard unchanged) this.currentSingleton = singleton; this.currentNodeKind = kind; this.currentNodeKey = nodeKey; - this.currentSlotOffset = slotOffset; - this.singletonDeweyBound = !resourceConfig.areDeweyIDsStored; - this.currentNode = null; // Clear - will be created lazily by getCurrentNode() + this.currentNode = null; // Clear - will be created lazily by getCurrentNode() this.singletonMode = true; + this.flyweightMode = false; return true; } /** - * Slow path for moveToSingleton when moving to a different page. Handles guard acquisition and - * release. + * Slow path for moveToSingleton when moving to a different page (read-only transactions only). + * Uses the reader's lookupSlotWithGuard with guard management. */ private boolean moveToSingletonSlowPath(final long nodeKey, final NodeStorageEngineReader reader) { - // Get raw slot data with full guard management var slotLocation = reader.lookupSlotWithGuard(nodeKey, IndexType.DOCUMENT, -1); if (slotLocation == null) { return false; } - final KeyValueLeafPage slotPage = slotLocation.page(); - final int slotOff = slotLocation.offset(); - final MemorySegment slotMemory = slotPage.getSlotMemory(); - final long baseOffset = slotPage.getSlotDataOffset(slotOff); - final int dataLength = slotPage.getSlotDataLength(slotOff); - final boolean fixedSlotFormat = slotPage.isFixedSlotFormat(slotOff); - final NodeKind kind; - if (fixedSlotFormat) { - kind = slotPage.getFixedSlotNodeKind(slotOff); - if (kind == null) { - slotLocation.guard().close(); - return moveToLegacy(nodeKey); - } - } else { - final byte kindByte = slotMemory.get(java.lang.foreign.ValueLayout.JAVA_BYTE, baseOffset); - kind = NodeKind.getKind(kindByte); - if (kind == NodeKind.DELETE) { - slotLocation.guard().close(); + return moveToSingletonFromPage(nodeKey, slotLocation.page(), reader, + nodeKey >> Constants.NDP_NODE_COUNT_EXPONENT, slotLocation.guard()); + } + + /** + * Move to a node on a given page using singleton mode. + * Shared logic for both write (TIL modified page) and read (guarded page) paths. + * + * @param nodeKey the node key + * @param page the page to read from + * @param reader the storage engine reader (for pageKey calculation) + * @param pageKey the pre-calculated page key + * @param newGuard the new page guard (null for TIL pages which don't need guarding) + * @return true if move succeeded + */ + private boolean moveToSingletonFromPage(final long nodeKey, final KeyValueLeafPage page, + final NodeStorageEngineReader reader, final long pageKey, final @Nullable PageGuard newGuard) { + final int slotOff = (int) (nodeKey & ((1 << Constants.NDP_NODE_COUNT_EXPONENT) - 1)); + + // Check records[] first: Java objects are authoritative during write transactions + // (modifications via prepareRecordForModification are NOT synced back to page heap) + final DataRecord fromRecords = page.getRecord(slotOff); + if (fromRecords != null) { + if (fromRecords.getKind() == NodeKind.DELETE) { + if (newGuard != null) { + newGuard.close(); + } return false; } + releaseCurrentPageGuard(); + @SuppressWarnings("unchecked") + final N node = (N) fromRecords; + this.currentNode = node; + this.currentNodeKind = (NodeKind) fromRecords.getKind(); + this.currentNodeKey = nodeKey; + this.currentSingleton = null; + this.singletonMode = false; + this.flyweightMode = false; + this.currentPageGuard = newGuard; + this.currentPage = page; + this.currentPageKey = pageKey; + return true; + } + + // Get slot data from page heap + MemorySegment data = page.getSlot(slotOff); + if (data == null) { + if (newGuard != null) { + newGuard.close(); + } + return false; + } + + // Read node kind from first byte + byte kindByte = data.get(java.lang.foreign.ValueLayout.JAVA_BYTE, 0); + NodeKind kind = NodeKind.getKind(kindByte); + + // Check for deleted node + if (kind == NodeKind.DELETE) { + if (newGuard != null) { + newGuard.close(); + } + return false; } // Get singleton instance for this node type ImmutableNode singleton = getSingletonForKind(kind); if (singleton == null) { // No singleton for this type (e.g., document root), fall back to legacy - slotLocation.guard().close(); + if (newGuard != null) { + newGuard.close(); + } return moveToLegacy(nodeKey); } // Release previous page guard ONLY NOW (after we know the new page is valid) releaseCurrentPageGuard(); - // Populate singleton from serialized data (NO ALLOCATION) - // Reuse BytesIn instance - just reset to new segment and offset (skip kind byte) - // Dewey bytes are bound lazily on demand to avoid byte[] allocation per moveTo. - if (fixedSlotFormat) { - if (!populateSingletonFromFixedSlot(singleton, kind, slotMemory, baseOffset, dataLength, nodeKey, null, - slotPage)) { - slotLocation.guard().close(); - return moveToLegacy(nodeKey); + // Check if this is a flyweight record in slotted page + final boolean isFlyweight = page.getSlottedPage() != null && page.getSlotNodeKindId(slotOff) > 0 + && singleton instanceof FlyweightNode; + if (isFlyweight) { + final FlyweightNode fn = (FlyweightNode) singleton; + // Bind flyweight directly to slotted page (zero-copy, no legacy parsing) + final int heapOffset = PageLayout.getDirHeapOffset(page.getSlottedPage(), slotOff); + final long recordBase = PageLayout.heapAbsoluteOffset(heapOffset); + fn.bind(page.getSlottedPage(), recordBase, nodeKey, slotOff); + // Propagate FSST symbol table for compressed string nodes + propagateFsstToFlyweight(fn, page); + // Propagate DeweyID from page to flyweight node (stored inline after record data). + // setDeweyIDBytes stores raw bytes lazily — no SirixDeweyID parsing until getDeweyID() called. + // MUST always set (even null) to clear stale DeweyID from previous singleton reuse. + if (resourceConfig.areDeweyIDsStored && fn instanceof Node node) { + node.setDeweyIDBytes(page.getDeweyIdAsByteArray(slotOff)); } } else { - reusableBytesIn.reset(slotMemory, baseOffset + 1); - populateSingleton(singleton, reusableBytesIn, nodeKey, null, kind, slotPage); + // Legacy format: populate from serialized data (NO ALLOCATION) + reusableBytesIn.reset(data, 1); + byte[] deweyId = resourceConfig.areDeweyIDsStored + ? page.getDeweyIdAsByteArray(slotOff) : null; + populateSingleton(singleton, reusableBytesIn, nodeKey, deweyId, kind, page); } // Update state - we're in singleton mode now with new page - this.currentPageGuard = slotLocation.guard(); - this.currentPage = slotLocation.page(); - this.currentPageKey = reader.pageKey(nodeKey, IndexType.DOCUMENT); + this.currentPageGuard = newGuard; + this.currentPage = page; + this.currentPageKey = pageKey; this.currentSingleton = singleton; this.currentNodeKind = kind; this.currentNodeKey = nodeKey; - this.currentSlotOffset = slotOff; - this.singletonDeweyBound = !resourceConfig.areDeweyIDsStored; - this.currentNode = null; // Clear - will be created lazily by getCurrentNode() + this.currentNode = null; // Clear - will be created lazily by getCurrentNode() this.singletonMode = true; + this.flyweightMode = false; return true; } - private boolean populateSingletonFromFixedSlot(final ImmutableNode singleton, final NodeKind kind, - final MemorySegment slotMemory, final long baseOffset, final int dataLength, final long nodeKey, - final byte[] deweyIdBytes, final KeyValueLeafPage page) { - final NodeKindLayout layout = kind.layoutDescriptor(); - if (!layout.isFixedSlotSupported() || dataLength < layout.fixedSlotSizeInBytes()) { - return false; - } - // Reject payload-bearing nodes with non-VALUE_BLOB payload refs (e.g., ATTRIBUTE_VECTOR) - if (layout.payloadRefCount() > 0 && !layout.hasSupportedPayloads()) { - return false; - } + /** + * Write-transaction singleton moveTo. Uses the writer's TIL for page resolution (modified pages). + * Same-page optimization caches the modified page between calls. + * Falls back to moveToLegacy if the page is not in TIL. + * + * @param nodeKey the node key to move to + * @param reader the underlying storage engine reader (for pageKey calculation) + * @param writer the storage engine writer (for TIL page resolution) + * @return true if the move was successful + */ + private boolean moveToSingletonWrite(final long nodeKey, final NodeStorageEngineReader reader, + final StorageEngineWriter writer) { + // Inline pageKey: all index types use exponent 10, avoids assertNotClosed + switch overhead + final long targetPageKey = nodeKey >> Constants.NDP_NODE_COUNT_EXPONENT; + final int slotOffset = (int) (nodeKey & ((1 << Constants.NDP_NODE_COUNT_EXPONENT) - 1)); + KeyValueLeafPage page; - switch (kind) { - case JSON_DOCUMENT -> { - if (!(singleton instanceof JsonDocumentRootNode node)) { - return false; - } - node.setNodeKey(nodeKey); - node.setFirstChildKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.FIRST_CHILD_KEY)); - node.setLastChildKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.LAST_CHILD_KEY)); - node.setDeweyIDBytes(deweyIdBytes); - node.bindFixedSlotLazy(slotMemory, baseOffset, layout); - return true; - } - case XML_DOCUMENT -> { - if (!(singleton instanceof XmlDocumentRootNode node)) { - return false; - } - node.setNodeKey(nodeKey); - node.setFirstChildKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.FIRST_CHILD_KEY)); - node.setLastChildKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.LAST_CHILD_KEY)); - node.setDeweyIDBytes(deweyIdBytes); - node.bindFixedSlotLazy(slotMemory, baseOffset, layout); - return true; - } - case OBJECT -> { - if (!(singleton instanceof ObjectNode node)) { - return false; - } - node.setNodeKey(nodeKey); - node.setParentKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.PARENT_KEY)); - node.setRightSiblingKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.RIGHT_SIBLING_KEY)); - node.setLeftSiblingKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.LEFT_SIBLING_KEY)); - node.setFirstChildKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.FIRST_CHILD_KEY)); - node.setDeweyIDBytes(deweyIdBytes); - node.bindFixedSlotLazy(slotMemory, baseOffset, layout); - return true; - } - case ARRAY -> { - if (!(singleton instanceof ArrayNode node)) { - return false; - } - node.setNodeKey(nodeKey); - node.setParentKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.PARENT_KEY)); - node.setPathNodeKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.PATH_NODE_KEY)); - node.setRightSiblingKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.RIGHT_SIBLING_KEY)); - node.setLeftSiblingKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.LEFT_SIBLING_KEY)); - node.setFirstChildKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.FIRST_CHILD_KEY)); - node.setDeweyIDBytes(deweyIdBytes); - node.bindFixedSlotLazy(slotMemory, baseOffset, layout); - return true; - } - case OBJECT_KEY -> { - if (!(singleton instanceof ObjectKeyNode node)) { - return false; - } - node.setNodeKey(nodeKey); - node.setParentKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.PARENT_KEY)); - node.setRightSiblingKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.RIGHT_SIBLING_KEY)); - node.setLeftSiblingKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.LEFT_SIBLING_KEY)); - node.setFirstChildKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.FIRST_CHILD_KEY)); - node.setNameKey(SlotLayoutAccessors.readIntField(slotMemory, baseOffset, layout, StructuralField.NAME_KEY)); - node.clearCachedName(); - node.setDeweyIDBytes(deweyIdBytes); - node.bindFixedSlotLazy(slotMemory, baseOffset, layout); - return true; - } - case BOOLEAN_VALUE -> { - if (!(singleton instanceof BooleanNode node)) { - return false; - } - node.setNodeKey(nodeKey); - node.setParentKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.PARENT_KEY)); - node.setRightSiblingKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.RIGHT_SIBLING_KEY)); - node.setLeftSiblingKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.LEFT_SIBLING_KEY)); - node.setValue(SlotLayoutAccessors.readBooleanField(slotMemory, baseOffset, layout, StructuralField.BOOLEAN_VALUE)); - node.setDeweyIDBytes(deweyIdBytes); - node.bindFixedSlotLazy(slotMemory, baseOffset, layout); - return true; - } - case NULL_VALUE -> { - if (!(singleton instanceof NullNode node)) { - return false; - } - node.setNodeKey(nodeKey); - node.setParentKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.PARENT_KEY)); - node.setRightSiblingKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.RIGHT_SIBLING_KEY)); - node.setLeftSiblingKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.LEFT_SIBLING_KEY)); - node.setDeweyIDBytes(deweyIdBytes); - node.bindFixedSlotLazy(slotMemory, baseOffset, layout); - return true; - } - case OBJECT_BOOLEAN_VALUE -> { - if (!(singleton instanceof ObjectBooleanNode node)) { - return false; - } - node.setNodeKey(nodeKey); - node.setParentKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.PARENT_KEY)); - node.setValue(SlotLayoutAccessors.readBooleanField(slotMemory, baseOffset, layout, StructuralField.BOOLEAN_VALUE)); - node.setDeweyIDBytes(deweyIdBytes); - node.bindFixedSlotLazy(slotMemory, baseOffset, layout); - return true; - } - case OBJECT_NULL_VALUE -> { - if (!(singleton instanceof ObjectNullNode node)) { - return false; - } - node.setNodeKey(nodeKey); - node.setParentKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.PARENT_KEY)); - node.setDeweyIDBytes(deweyIdBytes); - node.bindFixedSlotLazy(slotMemory, baseOffset, layout); - return true; - } - case NAMESPACE -> { - if (!(singleton instanceof NamespaceNode node)) { - return false; - } - node.setNodeKey(nodeKey); - node.setParentKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.PARENT_KEY)); - node.setPrefixKey(SlotLayoutAccessors.readIntField(slotMemory, baseOffset, layout, StructuralField.PREFIX_KEY)); - node.setLocalNameKey(SlotLayoutAccessors.readIntField(slotMemory, baseOffset, layout, StructuralField.LOCAL_NAME_KEY)); - node.setURIKey(SlotLayoutAccessors.readIntField(slotMemory, baseOffset, layout, StructuralField.URI_KEY)); - node.setName(EMPTY_QNM); - node.setDeweyIDBytes(deweyIdBytes); - node.bindFixedSlotLazy(slotMemory, baseOffset, layout); - return true; - } - case ELEMENT -> { - if (!(singleton instanceof ElementNode node)) { - return false; - } - node.setNodeKey(nodeKey); - node.setParentKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.PARENT_KEY)); - node.setRightSiblingKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.RIGHT_SIBLING_KEY)); - node.setLeftSiblingKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.LEFT_SIBLING_KEY)); - node.setFirstChildKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.FIRST_CHILD_KEY)); - node.setPrefixKey(SlotLayoutAccessors.readIntField(slotMemory, baseOffset, layout, StructuralField.PREFIX_KEY)); - node.setLocalNameKey(SlotLayoutAccessors.readIntField(slotMemory, baseOffset, layout, StructuralField.LOCAL_NAME_KEY)); - FixedSlotRecordMaterializer.readInlineVectorPayload(node, slotMemory, baseOffset, layout, 0, true); - FixedSlotRecordMaterializer.readInlineVectorPayload(node, slotMemory, baseOffset, layout, 1, false); - node.setName(EMPTY_QNM); - node.setDeweyIDBytes(deweyIdBytes); - node.bindFixedSlotLazy(slotMemory, baseOffset, layout); - return true; - } - case STRING_VALUE -> { - if (!(singleton instanceof StringNode node)) { - return false; - } - node.setNodeKey(nodeKey); - node.setParentKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.PARENT_KEY)); - node.setRightSiblingKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.RIGHT_SIBLING_KEY)); - node.setLeftSiblingKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.LEFT_SIBLING_KEY)); - // setLazyRawValue BEFORE bindFixedSlotLazy — setLazyRawValue sets lazySource and - // metadataParsed=true - final long strPointer = SlotLayoutAccessors.readPayloadPointer(slotMemory, baseOffset, layout, 0); - final int strLength = SlotLayoutAccessors.readPayloadLength(slotMemory, baseOffset, layout, 0); - final int strFlags = SlotLayoutAccessors.readPayloadFlags(slotMemory, baseOffset, layout, 0); - node.setLazyRawValue(slotMemory, baseOffset + strPointer, strLength, (strFlags & 1) != 0); - // Propagate FSST symbol table for decompression (use pre-parsed symbols) - final byte[] strFsstSymbols = page.getFsstSymbolTable(); - if (strFsstSymbols != null && strFsstSymbols.length > 0) { - node.setFsstSymbolTable(strFsstSymbols, page.getParsedFsstSymbols()); - } - node.setDeweyIDBytes(deweyIdBytes); - node.bindFixedSlotLazy(slotMemory, baseOffset, layout); - return true; - } - case OBJECT_STRING_VALUE -> { - if (!(singleton instanceof ObjectStringNode node)) { - return false; - } - node.setNodeKey(nodeKey); - node.setParentKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.PARENT_KEY)); - // setLazyRawValue BEFORE bindFixedSlotLazy — setLazyRawValue sets lazySource and - // metadataParsed=true - final long objStrPointer = SlotLayoutAccessors.readPayloadPointer(slotMemory, baseOffset, layout, 0); - final int objStrLength = SlotLayoutAccessors.readPayloadLength(slotMemory, baseOffset, layout, 0); - final int objStrFlags = SlotLayoutAccessors.readPayloadFlags(slotMemory, baseOffset, layout, 0); - node.setLazyRawValue(slotMemory, baseOffset + objStrPointer, objStrLength, (objStrFlags & 1) != 0); - // Propagate FSST symbol table for decompression (use pre-parsed symbols) - final byte[] objStrFsstSymbols = page.getFsstSymbolTable(); - if (objStrFsstSymbols != null && objStrFsstSymbols.length > 0) { - node.setFsstSymbolTable(objStrFsstSymbols, page.getParsedFsstSymbols()); - } - node.setDeweyIDBytes(deweyIdBytes); - node.bindFixedSlotLazy(slotMemory, baseOffset, layout); - return true; - } - case NUMBER_VALUE -> { - if (!(singleton instanceof NumberNode node)) { - return false; - } - node.setNodeKey(nodeKey); - node.setParentKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.PARENT_KEY)); - node.setRightSiblingKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.RIGHT_SIBLING_KEY)); - node.setLeftSiblingKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.LEFT_SIBLING_KEY)); - // setLazyNumberValue BEFORE bindFixedSlotLazy — setLazyNumberValue sets lazySource and - // metadataParsed=true - final long numPointer = SlotLayoutAccessors.readPayloadPointer(slotMemory, baseOffset, layout, 0); - final int numLength = SlotLayoutAccessors.readPayloadLength(slotMemory, baseOffset, layout, 0); - node.setLazyNumberValue(slotMemory, baseOffset + numPointer, numLength); - node.setDeweyIDBytes(deweyIdBytes); - node.bindFixedSlotLazy(slotMemory, baseOffset, layout); - return true; - } - case OBJECT_NUMBER_VALUE -> { - if (!(singleton instanceof ObjectNumberNode node)) { - return false; - } - node.setNodeKey(nodeKey); - node.setParentKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.PARENT_KEY)); - // setLazyNumberValue BEFORE bindFixedSlotLazy — setLazyNumberValue sets lazySource and - // metadataParsed=true - final long objNumPointer = SlotLayoutAccessors.readPayloadPointer(slotMemory, baseOffset, layout, 0); - final int objNumLength = SlotLayoutAccessors.readPayloadLength(slotMemory, baseOffset, layout, 0); - node.setLazyNumberValue(slotMemory, baseOffset + objNumPointer, objNumLength); - node.setDeweyIDBytes(deweyIdBytes); - node.bindFixedSlotLazy(slotMemory, baseOffset, layout); - return true; - } - case TEXT -> { - if (!(singleton instanceof TextNode node)) { - return false; - } - node.setNodeKey(nodeKey); - node.setParentKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.PARENT_KEY)); - node.setRightSiblingKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.RIGHT_SIBLING_KEY)); - node.setLeftSiblingKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.LEFT_SIBLING_KEY)); - // setLazyRawValue BEFORE bindFixedSlotLazy — setLazyRawValue sets lazySource and - // metadataParsed=true - final long textPointer = SlotLayoutAccessors.readPayloadPointer(slotMemory, baseOffset, layout, 0); - final int textLength = SlotLayoutAccessors.readPayloadLength(slotMemory, baseOffset, layout, 0); - final int textFlags = SlotLayoutAccessors.readPayloadFlags(slotMemory, baseOffset, layout, 0); - node.setLazyRawValue(slotMemory, baseOffset + textPointer, textLength, (textFlags & 1) != 0); - node.setDeweyIDBytes(deweyIdBytes); - node.bindFixedSlotLazy(slotMemory, baseOffset, layout); - return true; + // Same-page fast path: reuse cached modified page + if (currentPageKey == targetPageKey && currentPage != null && !currentPage.isClosed()) { + page = currentPage; + } else { + // Different page: get modified page from writer's TIL + page = writer.getModifiedPageForRead(targetPageKey, IndexType.DOCUMENT, -1); + if (page == null) { + // Page not in TIL — fall back to legacy (allocating) moveTo + return moveToLegacy(nodeKey); } - case COMMENT -> { - if (!(singleton instanceof CommentNode node)) { - return false; - } - node.setNodeKey(nodeKey); - node.setParentKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.PARENT_KEY)); - node.setRightSiblingKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.RIGHT_SIBLING_KEY)); - node.setLeftSiblingKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.LEFT_SIBLING_KEY)); - // setLazyRawValue BEFORE bindFixedSlotLazy — setLazyRawValue sets lazyValueSource - final long commentPointer = SlotLayoutAccessors.readPayloadPointer(slotMemory, baseOffset, layout, 0); - final int commentLength = SlotLayoutAccessors.readPayloadLength(slotMemory, baseOffset, layout, 0); - final int commentFlags = SlotLayoutAccessors.readPayloadFlags(slotMemory, baseOffset, layout, 0); - node.setLazyRawValue(slotMemory, baseOffset + commentPointer, commentLength, (commentFlags & 1) != 0); - node.setDeweyIDBytes(deweyIdBytes); - node.bindFixedSlotLazy(slotMemory, baseOffset, layout); - return true; + // Release previous guard (if any) and update page tracking + // TIL pages don't need guarding — they're pinned by the transaction + if (currentPageGuard != null) { + currentPageGuard.close(); + currentPageGuard = null; } - case ATTRIBUTE -> { - if (!(singleton instanceof AttributeNode node)) { - return false; - } - node.setNodeKey(nodeKey); - node.setParentKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.PARENT_KEY)); - node.setPrefixKey(SlotLayoutAccessors.readIntField(slotMemory, baseOffset, layout, StructuralField.PREFIX_KEY)); - node.setLocalNameKey(SlotLayoutAccessors.readIntField(slotMemory, baseOffset, layout, StructuralField.LOCAL_NAME_KEY)); - node.setURIKey(SlotLayoutAccessors.readIntField(slotMemory, baseOffset, layout, StructuralField.URI_KEY)); - // setLazyRawValue BEFORE bindFixedSlotLazy — setLazyRawValue sets lazyValueSource - final long attrPointer = SlotLayoutAccessors.readPayloadPointer(slotMemory, baseOffset, layout, 0); - final int attrLength = SlotLayoutAccessors.readPayloadLength(slotMemory, baseOffset, layout, 0); - node.setLazyRawValue(slotMemory, baseOffset + attrPointer, attrLength); - node.setName(EMPTY_QNM); - node.setDeweyIDBytes(deweyIdBytes); - node.bindFixedSlotLazy(slotMemory, baseOffset, layout); - return true; + currentPage = page; + currentPageKey = targetPageKey; + } + + // Check records[] first: authoritative for writes (prepareRecordForModification stores here) + final DataRecord fromRecords = page.getRecord(slotOffset); + if (fromRecords != null) { + if (fromRecords.getKind() == NodeKind.DELETE) { + return false; } - case PROCESSING_INSTRUCTION -> { - if (!(singleton instanceof PINode node)) { - return false; - } - node.setNodeKey(nodeKey); - node.setParentKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.PARENT_KEY)); - node.setRightSiblingKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.RIGHT_SIBLING_KEY)); - node.setLeftSiblingKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.LEFT_SIBLING_KEY)); - node.setFirstChildKey(SlotLayoutAccessors.readLongField(slotMemory, baseOffset, layout, StructuralField.FIRST_CHILD_KEY)); - node.setPrefixKey(SlotLayoutAccessors.readIntField(slotMemory, baseOffset, layout, StructuralField.PREFIX_KEY)); - node.setLocalNameKey(SlotLayoutAccessors.readIntField(slotMemory, baseOffset, layout, StructuralField.LOCAL_NAME_KEY)); - // setLazyRawValue BEFORE bindFixedSlotLazy — setLazyRawValue sets lazyValueSource - final long piPointer = SlotLayoutAccessors.readPayloadPointer(slotMemory, baseOffset, layout, 0); - final int piLength = SlotLayoutAccessors.readPayloadLength(slotMemory, baseOffset, layout, 0); - final int piFlags = SlotLayoutAccessors.readPayloadFlags(slotMemory, baseOffset, layout, 0); - node.setLazyRawValue(slotMemory, baseOffset + piPointer, piLength, (piFlags & 1) != 0); - node.setName(EMPTY_QNM); - node.setDeweyIDBytes(deweyIdBytes); - node.bindFixedSlotLazy(slotMemory, baseOffset, layout); - return true; + @SuppressWarnings("unchecked") + final N node = (N) fromRecords; + this.currentNode = node; + this.currentNodeKind = (NodeKind) fromRecords.getKind(); + this.currentNodeKey = nodeKey; + this.currentSingleton = null; + this.singletonMode = false; + this.flyweightMode = false; + return true; + } + + // Check slot data on modified page + final MemorySegment data = page.getSlot(slotOffset); + if (data == null) { + // Not in modified page heap either — fall back to legacy + return moveToLegacy(nodeKey); + } + + // Read node kind from first byte + final byte kindByte = data.get(java.lang.foreign.ValueLayout.JAVA_BYTE, 0); + final NodeKind kind = NodeKind.getKind(kindByte); + + if (kind == NodeKind.DELETE) { + return false; + } + + // Get singleton instance for this node type + final ImmutableNode singleton = getSingletonForKind(kind); + if (singleton == null) { + return moveToLegacy(nodeKey); + } + + // Bind singleton to page data (zero allocation) + // Cache slottedPage locally to avoid repeated virtual calls to getSlottedPage() + final MemorySegment sp = page.getSlottedPage(); + if (sp != null && singleton instanceof FlyweightNode fn) { + final int heapOffset = PageLayout.getDirHeapOffset(sp, slotOffset); + final long recordBase = PageLayout.heapAbsoluteOffset(heapOffset); + fn.bind(sp, recordBase, nodeKey, slotOffset); + // Propagate DeweyID lazily — no SirixDeweyID parsing until getDeweyID() called. + // MUST always set (even null) to clear stale DeweyID from previous singleton reuse. + if (resourceConfig.areDeweyIDsStored && fn instanceof Node node) { + node.setDeweyIDBytes(page.getDeweyIdAsByteArray(slotOffset)); } - default -> { - return false; + } else { + // Legacy format: populate singleton from serialized data (NO ALLOCATION) + reusableBytesIn.reset(data, 1); + final byte[] deweyId = resourceConfig.areDeweyIDsStored + ? page.getDeweyIdAsByteArray(slotOffset) : null; + populateSingleton(singleton, reusableBytesIn, nodeKey, deweyId, kind, page); + } + + // Update state — singleton mode, no guard needed for TIL pages + this.currentSingleton = singleton; + this.currentNodeKind = kind; + this.currentNodeKey = nodeKey; + this.currentNode = null; + this.singletonMode = true; + this.flyweightMode = false; + + return true; + } + + /** + * Propagate FSST symbol table from page to a flyweight string node. + * Required for lazy decompression of FSST-compressed strings in singleton mode. + */ + private static void propagateFsstToFlyweight(final FlyweightNode fn, final KeyValueLeafPage page) { + final byte[] fsstTable = page.getFsstSymbolTable(); + if (fsstTable != null && fsstTable.length > 0) { + if (fn instanceof StringNode sn) { + sn.setFsstSymbolTable(fsstTable); + } else if (fn instanceof ObjectStringNode osn) { + osn.setFsstSymbolTable(fsstTable); } } } /** - * Get the singleton instance for a given node kind. Lazily creates singletons on first use. + * Get the singleton instance for a given node kind. + * Lazily creates singletons on first use. * * @param kind the node kind * @return the singleton instance, or null if not supported */ private ImmutableNode getSingletonForKind(NodeKind kind) { + final int id = kind.getId() & 0xFF; + if (id >= singletonByKindId.length) { + return null; + } + ImmutableNode singleton = singletonByKindId[id]; + if (singleton != null) { + return singleton; + } + singleton = createSingletonForKind(kind); + if (singleton != null) { + singletonByKindId[id] = singleton; + } + return singleton; + } + + /** + * Create a singleton instance for the given node kind (cold path, called once per kind). + */ + private ImmutableNode createSingletonForKind(NodeKind kind) { return switch (kind) { - case OBJECT -> { - if (singletonObject == null) { - singletonObject = - new ObjectNode(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, resourceConfig.nodeHashFunction, (byte[]) null); - } - yield singletonObject; - } - case ARRAY -> { - if (singletonArray == null) { - singletonArray = - new ArrayNode(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, resourceConfig.nodeHashFunction, (byte[]) null); - } - yield singletonArray; - } - case OBJECT_KEY -> { - if (singletonObjectKey == null) { - singletonObjectKey = - new ObjectKeyNode(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, resourceConfig.nodeHashFunction, (byte[]) null); - } - yield singletonObjectKey; - } - case STRING_VALUE -> { - if (singletonString == null) { - singletonString = new StringNode(0, 0, 0, 0, 0, 0, 0, null, resourceConfig.nodeHashFunction, (byte[]) null); - } - yield singletonString; - } - case NUMBER_VALUE -> { - if (singletonNumber == null) { - singletonNumber = new NumberNode(0, 0, 0, 0, 0, 0, 0, 0, resourceConfig.nodeHashFunction, (byte[]) null); - } - yield singletonNumber; - } - case BOOLEAN_VALUE -> { - if (singletonBoolean == null) { - singletonBoolean = - new BooleanNode(0, 0, 0, 0, 0, 0, 0, false, resourceConfig.nodeHashFunction, (byte[]) null); - } - yield singletonBoolean; - } - case NULL_VALUE -> { - if (singletonNull == null) { - singletonNull = new NullNode(0, 0, 0, 0, 0, 0, 0, resourceConfig.nodeHashFunction, (byte[]) null); - } - yield singletonNull; - } - case OBJECT_STRING_VALUE -> { - if (singletonObjectString == null) { - singletonObjectString = - new ObjectStringNode(0, 0, 0, 0, 0, null, resourceConfig.nodeHashFunction, (byte[]) null); - } - yield singletonObjectString; - } - case OBJECT_NUMBER_VALUE -> { - if (singletonObjectNumber == null) { - singletonObjectNumber = - new ObjectNumberNode(0, 0, 0, 0, 0, 0, resourceConfig.nodeHashFunction, (byte[]) null); - } - yield singletonObjectNumber; - } - case OBJECT_BOOLEAN_VALUE -> { - if (singletonObjectBoolean == null) { - singletonObjectBoolean = - new ObjectBooleanNode(0, 0, 0, 0, 0, false, resourceConfig.nodeHashFunction, (byte[]) null); - } - yield singletonObjectBoolean; - } - case OBJECT_NULL_VALUE -> { - if (singletonObjectNull == null) { - singletonObjectNull = new ObjectNullNode(0, 0, 0, 0, 0, resourceConfig.nodeHashFunction, (byte[]) null); - } - yield singletonObjectNull; - } - case JSON_DOCUMENT -> { - if (singletonJsonDocumentRoot == null) { - singletonJsonDocumentRoot = new JsonDocumentRootNode(Fixed.DOCUMENT_NODE_KEY.getStandardProperty(), - Fixed.NULL_NODE_KEY.getStandardProperty(), Fixed.NULL_NODE_KEY.getStandardProperty(), 0, 0, - resourceConfig.nodeHashFunction); - } - yield singletonJsonDocumentRoot; - } - case XML_DOCUMENT -> { - if (singletonXmlDocumentRoot == null) { - singletonXmlDocumentRoot = new XmlDocumentRootNode(Fixed.DOCUMENT_NODE_KEY.getStandardProperty(), - Fixed.NULL_NODE_KEY.getStandardProperty(), Fixed.NULL_NODE_KEY.getStandardProperty(), 0, 0, - resourceConfig.nodeHashFunction); - } - yield singletonXmlDocumentRoot; - } - case ELEMENT -> { - if (singletonElement == null) { - singletonElement = new ElementNode(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, - resourceConfig.nodeHashFunction, (byte[]) null, null, null, EMPTY_QNM); - } - yield singletonElement; - } - case ATTRIBUTE -> { - if (singletonAttribute == null) { - singletonAttribute = new AttributeNode(0, 0, 0, 0, 0, 0, 0, 0, 0, new byte[0], - resourceConfig.nodeHashFunction, (byte[]) null, EMPTY_QNM); - } - yield singletonAttribute; - } - case NAMESPACE -> { - if (singletonNamespace == null) { - singletonNamespace = - new NamespaceNode(0, 0, 0, 0, 0, 0, 0, 0, 0, resourceConfig.nodeHashFunction, (byte[]) null, EMPTY_QNM); - } - yield singletonNamespace; - } - case TEXT -> { - if (singletonText == null) { - singletonText = - new TextNode(0, 0, 0, 0, 0, 0, 0, new byte[0], false, resourceConfig.nodeHashFunction, (byte[]) null); - } - yield singletonText; - } - case COMMENT -> { - if (singletonComment == null) { - singletonComment = - new CommentNode(0, 0, 0, 0, 0, 0, 0, new byte[0], false, resourceConfig.nodeHashFunction, (byte[]) null); - } - yield singletonComment; - } - case PROCESSING_INSTRUCTION -> { - if (singletonPI == null) { - singletonPI = new PINode(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, new byte[0], false, - resourceConfig.nodeHashFunction, (byte[]) null, EMPTY_QNM); - } - yield singletonPI; - } - // Other types fall back to legacy mode. + case OBJECT -> singletonObject = new ObjectNode(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + resourceConfig.nodeHashFunction, (byte[]) null); + case ARRAY -> singletonArray = new ArrayNode(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + resourceConfig.nodeHashFunction, (byte[]) null); + case OBJECT_KEY -> singletonObjectKey = new ObjectKeyNode(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + resourceConfig.nodeHashFunction, (byte[]) null); + case STRING_VALUE -> singletonString = new StringNode(0, 0, 0, 0, 0, 0, 0, null, + resourceConfig.nodeHashFunction, (byte[]) null); + case NUMBER_VALUE -> singletonNumber = new NumberNode(0, 0, 0, 0, 0, 0, 0, 0, + resourceConfig.nodeHashFunction, (byte[]) null); + case BOOLEAN_VALUE -> singletonBoolean = new BooleanNode(0, 0, 0, 0, 0, 0, 0, false, + resourceConfig.nodeHashFunction, (byte[]) null); + case NULL_VALUE -> singletonNull = new NullNode(0, 0, 0, 0, 0, 0, 0, + resourceConfig.nodeHashFunction, (byte[]) null); + case OBJECT_STRING_VALUE -> singletonObjectString = new ObjectStringNode(0, 0, 0, 0, 0, null, + resourceConfig.nodeHashFunction, (byte[]) null); + case OBJECT_NUMBER_VALUE -> singletonObjectNumber = new ObjectNumberNode(0, 0, 0, 0, 0, 0, + resourceConfig.nodeHashFunction, (byte[]) null); + case OBJECT_BOOLEAN_VALUE -> singletonObjectBoolean = new ObjectBooleanNode(0, 0, 0, 0, 0, false, + resourceConfig.nodeHashFunction, (byte[]) null); + case OBJECT_NULL_VALUE -> singletonObjectNull = new ObjectNullNode(0, 0, 0, 0, 0, + resourceConfig.nodeHashFunction, (byte[]) null); + case JSON_DOCUMENT -> singletonJsonDocRoot = new JsonDocumentRootNode(0, resourceConfig.nodeHashFunction); + case ELEMENT -> singletonElement = new ElementNode(0, resourceConfig.nodeHashFunction); + case ATTRIBUTE -> singletonAttribute = new AttributeNode(0, resourceConfig.nodeHashFunction); + case TEXT -> singletonText = new TextNode(0, resourceConfig.nodeHashFunction); + case COMMENT -> singletonComment = new CommentNode(0, resourceConfig.nodeHashFunction); + case PROCESSING_INSTRUCTION -> singletonPI = new PINode(0, resourceConfig.nodeHashFunction); + case NAMESPACE -> singletonNamespace = new NamespaceNode(0, resourceConfig.nodeHashFunction); + case XML_DOCUMENT -> singletonXmlDocRoot = new XmlDocumentRootNode(0, resourceConfig.nodeHashFunction); default -> null; }; } - + /** * Populate a singleton node from serialized data. * * @param singleton the singleton to populate - * @param source the BytesIn source positioned after the kind byte - * @param nodeKey the node key - * @param deweyId the DeweyID bytes - * @param kind the node kind + * @param source the BytesIn source positioned after the kind byte + * @param nodeKey the node key + * @param deweyId the DeweyID bytes + * @param kind the node kind */ - private void populateSingleton(ImmutableNode singleton, BytesIn source, long nodeKey, byte[] deweyId, - NodeKind kind, KeyValueLeafPage page) { + private void populateSingleton(ImmutableNode singleton, BytesIn source, + long nodeKey, byte[] deweyId, NodeKind kind, + KeyValueLeafPage page) { switch (kind) { - case OBJECT -> - ((ObjectNode) singleton).readFrom(source, nodeKey, deweyId, resourceConfig.nodeHashFunction, resourceConfig); - case ARRAY -> - ((ArrayNode) singleton).readFrom(source, nodeKey, deweyId, resourceConfig.nodeHashFunction, resourceConfig); - case OBJECT_KEY -> - ((ObjectKeyNode) singleton).readFrom(source, nodeKey, deweyId, resourceConfig.nodeHashFunction, resourceConfig); + case OBJECT -> ((ObjectNode) singleton).readFrom(source, nodeKey, deweyId, + resourceConfig.nodeHashFunction, resourceConfig); + case ARRAY -> ((ArrayNode) singleton).readFrom(source, nodeKey, deweyId, + resourceConfig.nodeHashFunction, resourceConfig); + case OBJECT_KEY -> ((ObjectKeyNode) singleton).readFrom(source, nodeKey, deweyId, + resourceConfig.nodeHashFunction, resourceConfig); case STRING_VALUE -> { StringNode stringNode = (StringNode) singleton; stringNode.readFrom(source, nodeKey, deweyId, resourceConfig.nodeHashFunction, resourceConfig); - // Propagate FSST symbol table for decompression (use pre-parsed symbols) + // Propagate FSST symbol table for decompression byte[] fsstSymbolTable = page.getFsstSymbolTable(); if (fsstSymbolTable != null && fsstSymbolTable.length > 0) { - stringNode.setFsstSymbolTable(fsstSymbolTable, page.getParsedFsstSymbols()); + stringNode.setFsstSymbolTable(fsstSymbolTable); } } - case NUMBER_VALUE -> - ((NumberNode) singleton).readFrom(source, nodeKey, deweyId, resourceConfig.nodeHashFunction, resourceConfig); - case BOOLEAN_VALUE -> - ((BooleanNode) singleton).readFrom(source, nodeKey, deweyId, resourceConfig.nodeHashFunction, resourceConfig); - case NULL_VALUE -> - ((NullNode) singleton).readFrom(source, nodeKey, deweyId, resourceConfig.nodeHashFunction, resourceConfig); + case NUMBER_VALUE -> ((NumberNode) singleton).readFrom(source, nodeKey, deweyId, + resourceConfig.nodeHashFunction, resourceConfig); + case BOOLEAN_VALUE -> ((BooleanNode) singleton).readFrom(source, nodeKey, deweyId, + resourceConfig.nodeHashFunction, resourceConfig); + case NULL_VALUE -> ((NullNode) singleton).readFrom(source, nodeKey, deweyId, + resourceConfig.nodeHashFunction, resourceConfig); case OBJECT_STRING_VALUE -> { ObjectStringNode objectStringNode = (ObjectStringNode) singleton; objectStringNode.readFrom(source, nodeKey, deweyId, resourceConfig.nodeHashFunction, resourceConfig); - // Propagate FSST symbol table for decompression (use pre-parsed symbols) + // Propagate FSST symbol table for decompression byte[] fsstSymbolTable = page.getFsstSymbolTable(); if (fsstSymbolTable != null && fsstSymbolTable.length > 0) { - objectStringNode.setFsstSymbolTable(fsstSymbolTable, page.getParsedFsstSymbols()); + objectStringNode.setFsstSymbolTable(fsstSymbolTable); } } case OBJECT_NUMBER_VALUE -> ((ObjectNumberNode) singleton).readFrom(source, nodeKey, deweyId, @@ -1109,27 +1055,27 @@ private void populateSingleton(ImmutableNode singleton, BytesIn source, long resourceConfig.nodeHashFunction, resourceConfig); case JSON_DOCUMENT -> ((JsonDocumentRootNode) singleton).readFrom(source, nodeKey, deweyId, resourceConfig.nodeHashFunction, resourceConfig); + case ELEMENT -> ((ElementNode) singleton).readFrom(source, nodeKey, deweyId, + resourceConfig.nodeHashFunction, resourceConfig); + case ATTRIBUTE -> ((AttributeNode) singleton).readFrom(source, nodeKey, deweyId, + resourceConfig.nodeHashFunction, resourceConfig); + case TEXT -> ((TextNode) singleton).readFrom(source, nodeKey, deweyId, + resourceConfig.nodeHashFunction, resourceConfig); + case COMMENT -> ((CommentNode) singleton).readFrom(source, nodeKey, deweyId, + resourceConfig.nodeHashFunction, resourceConfig); + case PROCESSING_INSTRUCTION -> ((PINode) singleton).readFrom(source, nodeKey, deweyId, + resourceConfig.nodeHashFunction, resourceConfig); + case NAMESPACE -> ((NamespaceNode) singleton).readFrom(source, nodeKey, deweyId, + resourceConfig.nodeHashFunction, resourceConfig); case XML_DOCUMENT -> ((XmlDocumentRootNode) singleton).readFrom(source, nodeKey, deweyId, resourceConfig.nodeHashFunction, resourceConfig); - case ELEMENT -> - ((ElementNode) singleton).readFrom(source, nodeKey, deweyId, resourceConfig.nodeHashFunction, resourceConfig); - case ATTRIBUTE -> - ((AttributeNode) singleton).readFrom(source, nodeKey, deweyId, resourceConfig.nodeHashFunction, resourceConfig); - case NAMESPACE -> - ((NamespaceNode) singleton).readFrom(source, nodeKey, deweyId, resourceConfig.nodeHashFunction, resourceConfig); - case TEXT -> - ((TextNode) singleton).readFrom(source, nodeKey, deweyId, resourceConfig.nodeHashFunction, resourceConfig); - case COMMENT -> - ((CommentNode) singleton).readFrom(source, nodeKey, deweyId, resourceConfig.nodeHashFunction, resourceConfig); - case PROCESSING_INSTRUCTION -> - ((PINode) singleton).readFrom(source, nodeKey, deweyId, resourceConfig.nodeHashFunction, resourceConfig); default -> throw new IllegalStateException("Unexpected singleton kind: " + kind); } } - + /** - * Move to an item in the item list (negative keys). Falls back to object mode since item list uses - * objects. + * Move to an item in the item list (negative keys). + * Falls back to object mode since item list uses objects. * * @param nodeKey the negative node key * @return true if the move was successful @@ -1138,9 +1084,10 @@ private boolean moveToItemList(final long nodeKey) { if (itemList.size() > 0) { DataRecord item = itemList.getItem(nodeKey); if (item != null) { - // Move succeeded - release previous page guard and switch to object mode. + // Move succeeded - release previous page guard and switch to object mode releaseCurrentPageGuard(); - // noinspection unchecked + flyweightMode = false; + //noinspection unchecked setCurrentNode((N) item); this.currentNodeKey = nodeKey; return true; @@ -1149,9 +1096,9 @@ private boolean moveToItemList(final long nodeKey) { // Item not found - keep the current position unchanged return false; } - + /** - * Legacy object-based moveTo path. + * Legacy object-based moveTo for when flyweight mode is not available. * * @param nodeKey the node key to move to * @return true if the move was successful @@ -1160,43 +1107,580 @@ private boolean moveToLegacy(final long nodeKey) { DataRecord newNode; try { newNode = storageEngineReader.getRecord(nodeKey, IndexType.DOCUMENT, -1); - } catch (final SirixIOException | UncheckedIOException | IllegalArgumentException | IllegalStateException e) { + } catch (final SirixIOException | UncheckedIOException | IllegalArgumentException e) { newNode = null; } if (newNode == null) { return false; } else { - // Only release guard if we were in singleton mode. - if (singletonMode) { + // Only release guard if we were in flyweight/singleton mode + if (flyweightMode || singletonMode) { releaseCurrentPageGuard(); + flyweightMode = false; singletonMode = false; } - // noinspection unchecked + //noinspection unchecked setCurrentNode((N) newNode); this.currentNodeKey = nodeKey; return true; } } - + /** - * Release the current page guard if one is held. This allows the page to be evicted if needed. + * Release the current page guard if one is held. + * This allows the page to be evicted if needed. */ protected void releaseCurrentPageGuard() { if (currentPageGuard != null) { currentPageGuard.close(); currentPageGuard = null; + currentPage = null; + currentPageKey = -1; + } + } + + /** + * Parse the field offsets from the current slot for fast getter access. + * This is called once per moveTo() and caches the byte offset of each field. + *

+ * The slot format starts with: + * - Byte 0: NodeKind byte + * - Byte 1+: Node-specific fields (varints) + *

+ * Field order varies by node kind, but common structural nodes follow: + * - parentKey (delta varint) + * - prevRev (signed varint) + * - lastModRev (signed varint) + * - [pathNodeKey for ARRAY] (delta varint) + * - rightSiblingKey (delta varint) + * - leftSiblingKey (delta varint) + * - firstChildKey (delta varint) for structural nodes + * - lastChildKey (delta varint) for structural nodes + * - childCount (signed varint) if storeChildCount + * - hash (8 bytes fixed) if hashType != NONE + * - descendantCount (signed varint) if hashType != NONE + */ + protected void parseFieldOffsets() { + // Start after NodeKind byte + int offset = 1; + + switch (currentNodeKind) { + case OBJECT -> parseObjectNodeOffsets(offset); + case ARRAY -> parseArrayNodeOffsets(offset); + case OBJECT_KEY -> parseObjectKeyNodeOffsets(offset); + // Non-object value nodes have siblings (used in arrays) + case STRING_VALUE -> parseStringValueNodeOffsets(offset); + case NUMBER_VALUE -> parseNumberValueNodeOffsets(offset); + case BOOLEAN_VALUE -> parseBooleanValueNodeOffsets(offset); + case NULL_VALUE -> parseNullValueNodeOffsets(offset); + // Object value nodes have no siblings (single child of ObjectKeyNode) + case OBJECT_STRING_VALUE -> parseObjectStringValueNodeOffsets(offset); + case OBJECT_NUMBER_VALUE -> parseObjectNumberValueNodeOffsets(offset); + case OBJECT_BOOLEAN_VALUE -> parseObjectBooleanValueNodeOffsets(offset); + case OBJECT_NULL_VALUE -> parseObjectNullValueNodeOffsets(offset); + case JSON_DOCUMENT -> { + // JSON_DOCUMENT has special serialization - fall back to object mode + // for simplicity. Document root is typically only visited once. + java.util.Arrays.fill(cachedFieldOffsets, -1); + } + default -> { + // For unsupported node kinds, set all offsets to -1 (use object fallback) + java.util.Arrays.fill(cachedFieldOffsets, -1); + } + } + } + + /** + * Parse field offsets for OBJECT node. + * Format: parentKey, prevRev, lastModRev, rightSiblingKey, leftSiblingKey, + * firstChildKey, lastChildKey, [childCount], [hash, descendantCount] + */ + private void parseObjectNodeOffsets(int offset) { + cachedFieldOffsets[FIELD_PARENT_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_PREV_REVISION] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_LAST_MOD_REVISION] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_RIGHT_SIBLING_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_LEFT_SIBLING_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_FIRST_CHILD_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_LAST_CHILD_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + // Optional childCount + if (resourceConfig.storeChildCount()) { + cachedFieldOffsets[FIELD_CHILD_COUNT] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + } else { + cachedFieldOffsets[FIELD_CHILD_COUNT] = -1; + } + + // Optional hash and descendant count + if (resourceConfig.hashType != HashType.NONE) { + cachedFieldOffsets[FIELD_HASH] = offset; + offset += 8; // Fixed 8 bytes for hash + cachedFieldOffsets[FIELD_DESCENDANT_COUNT] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + } else { + cachedFieldOffsets[FIELD_HASH] = -1; + cachedFieldOffsets[FIELD_DESCENDANT_COUNT] = -1; + } + + // OBJECT nodes don't have nameKey/pathNodeKey/value + cachedFieldOffsets[FIELD_NAME_KEY] = -1; + cachedFieldOffsets[FIELD_PATH_NODE_KEY] = -1; + cachedFieldOffsets[FIELD_VALUE] = -1; + cachedFieldOffsets[FIELD_END] = offset; + } + + /** + * Parse field offsets for ARRAY node. + * Format: parentKey, prevRev, lastModRev, pathNodeKey, rightSiblingKey, leftSiblingKey, + * firstChildKey, lastChildKey, [childCount], [hash, descendantCount] + */ + private void parseArrayNodeOffsets(int offset) { + cachedFieldOffsets[FIELD_PARENT_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_PREV_REVISION] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_LAST_MOD_REVISION] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_PATH_NODE_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_RIGHT_SIBLING_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_LEFT_SIBLING_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_FIRST_CHILD_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_LAST_CHILD_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + if (resourceConfig.storeChildCount()) { + cachedFieldOffsets[FIELD_CHILD_COUNT] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + } else { + cachedFieldOffsets[FIELD_CHILD_COUNT] = -1; + } + + if (resourceConfig.hashType != HashType.NONE) { + cachedFieldOffsets[FIELD_HASH] = offset; + offset += 8; + cachedFieldOffsets[FIELD_DESCENDANT_COUNT] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + } else { + cachedFieldOffsets[FIELD_HASH] = -1; + cachedFieldOffsets[FIELD_DESCENDANT_COUNT] = -1; + } + + cachedFieldOffsets[FIELD_NAME_KEY] = -1; + cachedFieldOffsets[FIELD_VALUE] = -1; + cachedFieldOffsets[FIELD_END] = offset; + } + + /** + * Parse field offsets for OBJECT_KEY node. + * Format: parentKey, prevRev, lastModRev, pathNodeKey, rightSiblingKey, + * leftSiblingKey, firstChildKey, nameKey, [hash, descendantCount] + */ + private void parseObjectKeyNodeOffsets(int offset) { + cachedFieldOffsets[FIELD_PARENT_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_PREV_REVISION] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_LAST_MOD_REVISION] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_PATH_NODE_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_RIGHT_SIBLING_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_LEFT_SIBLING_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_FIRST_CHILD_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_NAME_KEY] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + + if (resourceConfig.hashType != HashType.NONE) { + cachedFieldOffsets[FIELD_HASH] = offset; + offset += 8; + cachedFieldOffsets[FIELD_DESCENDANT_COUNT] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + } else { + cachedFieldOffsets[FIELD_HASH] = -1; + cachedFieldOffsets[FIELD_DESCENDANT_COUNT] = -1; + } + + // OBJECT_KEY has no lastChildKey, childCount + cachedFieldOffsets[FIELD_LAST_CHILD_KEY] = -1; + cachedFieldOffsets[FIELD_CHILD_COUNT] = -1; + cachedFieldOffsets[FIELD_VALUE] = -1; + cachedFieldOffsets[FIELD_END] = offset; + } + + /** + * Parse field offsets for STRING_VALUE/OBJECT_STRING_VALUE node. + * Format: parentKey, prevRev, lastModRev, rightSiblingKey, leftSiblingKey, [hash], valueLength, value + */ + private void parseStringValueNodeOffsets(int offset) { + cachedFieldOffsets[FIELD_PARENT_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_PREV_REVISION] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_LAST_MOD_REVISION] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_RIGHT_SIBLING_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_LEFT_SIBLING_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + if (resourceConfig.hashType != HashType.NONE) { + cachedFieldOffsets[FIELD_HASH] = offset; + offset += 8; + } else { + cachedFieldOffsets[FIELD_HASH] = -1; + } + + // Value starts at current offset (length + bytes) + cachedFieldOffsets[FIELD_VALUE] = offset; + + // Leaf nodes don't have children + cachedFieldOffsets[FIELD_FIRST_CHILD_KEY] = -1; + cachedFieldOffsets[FIELD_LAST_CHILD_KEY] = -1; + cachedFieldOffsets[FIELD_CHILD_COUNT] = -1; + cachedFieldOffsets[FIELD_DESCENDANT_COUNT] = -1; + cachedFieldOffsets[FIELD_NAME_KEY] = -1; + cachedFieldOffsets[FIELD_PATH_NODE_KEY] = -1; + cachedFieldOffsets[FIELD_END] = offset; // Value parsing done on demand + } + + /** + * Parse field offsets for NUMBER_VALUE/OBJECT_NUMBER_VALUE node. + * Format: parentKey, prevRev, lastModRev, rightSiblingKey, leftSiblingKey, [hash], numberValue + */ + private void parseNumberValueNodeOffsets(int offset) { + cachedFieldOffsets[FIELD_PARENT_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_PREV_REVISION] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_LAST_MOD_REVISION] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_RIGHT_SIBLING_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_LEFT_SIBLING_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + if (resourceConfig.hashType != HashType.NONE) { + cachedFieldOffsets[FIELD_HASH] = offset; + offset += 8; + } else { + cachedFieldOffsets[FIELD_HASH] = -1; + } + + cachedFieldOffsets[FIELD_VALUE] = offset; + + cachedFieldOffsets[FIELD_FIRST_CHILD_KEY] = -1; + cachedFieldOffsets[FIELD_LAST_CHILD_KEY] = -1; + cachedFieldOffsets[FIELD_CHILD_COUNT] = -1; + cachedFieldOffsets[FIELD_DESCENDANT_COUNT] = -1; + cachedFieldOffsets[FIELD_NAME_KEY] = -1; + cachedFieldOffsets[FIELD_PATH_NODE_KEY] = -1; + cachedFieldOffsets[FIELD_END] = offset; + } + + /** + * Parse field offsets for BOOLEAN_VALUE/OBJECT_BOOLEAN_VALUE node. + * Format: parentKey, prevRev, lastModRev, rightSiblingKey, leftSiblingKey, [hash], booleanValue + */ + private void parseBooleanValueNodeOffsets(int offset) { + cachedFieldOffsets[FIELD_PARENT_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_PREV_REVISION] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_LAST_MOD_REVISION] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_RIGHT_SIBLING_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_LEFT_SIBLING_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + if (resourceConfig.hashType != HashType.NONE) { + cachedFieldOffsets[FIELD_HASH] = offset; + offset += 8; + } else { + cachedFieldOffsets[FIELD_HASH] = -1; + } + + cachedFieldOffsets[FIELD_VALUE] = offset; + + cachedFieldOffsets[FIELD_FIRST_CHILD_KEY] = -1; + cachedFieldOffsets[FIELD_LAST_CHILD_KEY] = -1; + cachedFieldOffsets[FIELD_CHILD_COUNT] = -1; + cachedFieldOffsets[FIELD_DESCENDANT_COUNT] = -1; + cachedFieldOffsets[FIELD_NAME_KEY] = -1; + cachedFieldOffsets[FIELD_PATH_NODE_KEY] = -1; + cachedFieldOffsets[FIELD_END] = offset; + } + + /** + * Parse field offsets for NULL_VALUE node (used in arrays). + * Format: parentKey, prevRev, lastModRev, rightSiblingKey, leftSiblingKey, [hash] + */ + private void parseNullValueNodeOffsets(int offset) { + cachedFieldOffsets[FIELD_PARENT_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_PREV_REVISION] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_LAST_MOD_REVISION] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_RIGHT_SIBLING_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_LEFT_SIBLING_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + if (resourceConfig.hashType != HashType.NONE) { + cachedFieldOffsets[FIELD_HASH] = offset; + offset += 8; + } else { + cachedFieldOffsets[FIELD_HASH] = -1; } - currentPage = null; - currentPageKey = -1; - currentSlotOffset = -1; - singletonDeweyBound = true; + + cachedFieldOffsets[FIELD_FIRST_CHILD_KEY] = -1; + cachedFieldOffsets[FIELD_LAST_CHILD_KEY] = -1; + cachedFieldOffsets[FIELD_CHILD_COUNT] = -1; + cachedFieldOffsets[FIELD_DESCENDANT_COUNT] = -1; + cachedFieldOffsets[FIELD_NAME_KEY] = -1; + cachedFieldOffsets[FIELD_PATH_NODE_KEY] = -1; + cachedFieldOffsets[FIELD_VALUE] = -1; + cachedFieldOffsets[FIELD_END] = offset; + } + + // ==================== OBJECT_* VALUE NODES (no siblings) ==================== + + /** + * Parse field offsets for OBJECT_STRING_VALUE node. + * Format: parentKey, prevRev, lastModRev, [hash], stringValue + * Note: No sibling keys - single child of ObjectKeyNode. + */ + private void parseObjectStringValueNodeOffsets(int offset) { + cachedFieldOffsets[FIELD_PARENT_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_PREV_REVISION] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_LAST_MOD_REVISION] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + + if (resourceConfig.hashType != HashType.NONE) { + cachedFieldOffsets[FIELD_HASH] = offset; + offset += 8; + } else { + cachedFieldOffsets[FIELD_HASH] = -1; + } + + cachedFieldOffsets[FIELD_VALUE] = offset; + + // No siblings for object value nodes + cachedFieldOffsets[FIELD_RIGHT_SIBLING_KEY] = -1; + cachedFieldOffsets[FIELD_LEFT_SIBLING_KEY] = -1; + cachedFieldOffsets[FIELD_FIRST_CHILD_KEY] = -1; + cachedFieldOffsets[FIELD_LAST_CHILD_KEY] = -1; + cachedFieldOffsets[FIELD_CHILD_COUNT] = -1; + cachedFieldOffsets[FIELD_DESCENDANT_COUNT] = -1; + cachedFieldOffsets[FIELD_NAME_KEY] = -1; + cachedFieldOffsets[FIELD_PATH_NODE_KEY] = -1; + cachedFieldOffsets[FIELD_END] = offset; + } + + /** + * Parse field offsets for OBJECT_NUMBER_VALUE node. + * Format: parentKey, prevRev, lastModRev, [hash], numberValue + * Note: No sibling keys - single child of ObjectKeyNode. + */ + private void parseObjectNumberValueNodeOffsets(int offset) { + cachedFieldOffsets[FIELD_PARENT_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_PREV_REVISION] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_LAST_MOD_REVISION] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + + if (resourceConfig.hashType != HashType.NONE) { + cachedFieldOffsets[FIELD_HASH] = offset; + offset += 8; + } else { + cachedFieldOffsets[FIELD_HASH] = -1; + } + + cachedFieldOffsets[FIELD_VALUE] = offset; + + // No siblings for object value nodes + cachedFieldOffsets[FIELD_RIGHT_SIBLING_KEY] = -1; + cachedFieldOffsets[FIELD_LEFT_SIBLING_KEY] = -1; + cachedFieldOffsets[FIELD_FIRST_CHILD_KEY] = -1; + cachedFieldOffsets[FIELD_LAST_CHILD_KEY] = -1; + cachedFieldOffsets[FIELD_CHILD_COUNT] = -1; + cachedFieldOffsets[FIELD_DESCENDANT_COUNT] = -1; + cachedFieldOffsets[FIELD_NAME_KEY] = -1; + cachedFieldOffsets[FIELD_PATH_NODE_KEY] = -1; + cachedFieldOffsets[FIELD_END] = offset; + } + + /** + * Parse field offsets for OBJECT_BOOLEAN_VALUE node. + * Format: parentKey, prevRev, lastModRev, [hash], booleanValue + * Note: No sibling keys - single child of ObjectKeyNode. + */ + private void parseObjectBooleanValueNodeOffsets(int offset) { + cachedFieldOffsets[FIELD_PARENT_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_PREV_REVISION] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_LAST_MOD_REVISION] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + + if (resourceConfig.hashType != HashType.NONE) { + cachedFieldOffsets[FIELD_HASH] = offset; + offset += 8; + } else { + cachedFieldOffsets[FIELD_HASH] = -1; + } + + cachedFieldOffsets[FIELD_VALUE] = offset; + + // No siblings for object value nodes + cachedFieldOffsets[FIELD_RIGHT_SIBLING_KEY] = -1; + cachedFieldOffsets[FIELD_LEFT_SIBLING_KEY] = -1; + cachedFieldOffsets[FIELD_FIRST_CHILD_KEY] = -1; + cachedFieldOffsets[FIELD_LAST_CHILD_KEY] = -1; + cachedFieldOffsets[FIELD_CHILD_COUNT] = -1; + cachedFieldOffsets[FIELD_DESCENDANT_COUNT] = -1; + cachedFieldOffsets[FIELD_NAME_KEY] = -1; + cachedFieldOffsets[FIELD_PATH_NODE_KEY] = -1; + cachedFieldOffsets[FIELD_END] = offset; + } + + /** + * Parse field offsets for OBJECT_NULL_VALUE node. + * Format: parentKey, prevRev, lastModRev, [hash] + * Note: No sibling keys - single child of ObjectKeyNode. + */ + private void parseObjectNullValueNodeOffsets(int offset) { + cachedFieldOffsets[FIELD_PARENT_KEY] = offset; + offset += DeltaVarIntCodec.deltaLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_PREV_REVISION] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + + cachedFieldOffsets[FIELD_LAST_MOD_REVISION] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + + if (resourceConfig.hashType != HashType.NONE) { + cachedFieldOffsets[FIELD_HASH] = offset; + offset += 8; + } else { + cachedFieldOffsets[FIELD_HASH] = -1; + } + + // No siblings for object value nodes + cachedFieldOffsets[FIELD_RIGHT_SIBLING_KEY] = -1; + cachedFieldOffsets[FIELD_LEFT_SIBLING_KEY] = -1; + cachedFieldOffsets[FIELD_FIRST_CHILD_KEY] = -1; + cachedFieldOffsets[FIELD_LAST_CHILD_KEY] = -1; + cachedFieldOffsets[FIELD_CHILD_COUNT] = -1; + cachedFieldOffsets[FIELD_DESCENDANT_COUNT] = -1; + cachedFieldOffsets[FIELD_NAME_KEY] = -1; + cachedFieldOffsets[FIELD_PATH_NODE_KEY] = -1; + cachedFieldOffsets[FIELD_VALUE] = -1; + cachedFieldOffsets[FIELD_END] = offset; + } + + /** + * Parse field offsets for JSON_DOCUMENT node. + * Format: firstChildKey (varint), descendantCount (8 bytes) + * Note: JSON_DOCUMENT has fixed parent, prevRev, lastModRev values, not serialized. + */ + private void parseJsonDocumentNodeOffsets(int offset) { + // JSON_DOCUMENT has fixed values for these, not serialized: + // - parentKey = NULL_NODE_KEY + // - prevRev = NULL_REVISION_NUMBER + // - lastModRev = NULL_REVISION_NUMBER + cachedFieldOffsets[FIELD_PARENT_KEY] = -1; // Fixed value, not serialized + cachedFieldOffsets[FIELD_PREV_REVISION] = -1; // Fixed value + cachedFieldOffsets[FIELD_LAST_MOD_REVISION] = -1; // Fixed value + + // firstChildKey is a plain varint (not delta encoded) + cachedFieldOffsets[FIELD_FIRST_CHILD_KEY] = offset; + offset += DeltaVarIntCodec.varintLength(currentSlot, offset); + + // In JSON_DOCUMENT, firstChildKey == lastChildKey + cachedFieldOffsets[FIELD_LAST_CHILD_KEY] = -1; // Same as firstChildKey + + // descendantCount is always stored as 8-byte long + cachedFieldOffsets[FIELD_DESCENDANT_COUNT] = offset; + offset += 8; + + // These fields don't exist for JSON_DOCUMENT + cachedFieldOffsets[FIELD_RIGHT_SIBLING_KEY] = -1; + cachedFieldOffsets[FIELD_LEFT_SIBLING_KEY] = -1; + cachedFieldOffsets[FIELD_CHILD_COUNT] = -1; + cachedFieldOffsets[FIELD_HASH] = -1; + cachedFieldOffsets[FIELD_NAME_KEY] = -1; + cachedFieldOffsets[FIELD_PATH_NODE_KEY] = -1; + cachedFieldOffsets[FIELD_VALUE] = -1; + cachedFieldOffsets[FIELD_END] = offset; } @Override public boolean moveToRightSibling() { assertNotClosed(); - // Use cursor getter and avoid unnecessary materialization. + // Use flyweight getter if available to avoid node materialization if (!hasRightSibling()) { return false; } @@ -1206,7 +1690,7 @@ public boolean moveToRightSibling() { @Override public long getNodeKey() { assertNotClosed(); - if (singletonMode) { + if ((FLYWEIGHT_ENABLED && flyweightMode) || (SINGLETON_ENABLED && singletonMode)) { return currentNodeKey; } return getCurrentNode().getNodeKey(); @@ -1215,20 +1699,23 @@ public long getNodeKey() { @Override public long getHash() { assertNotClosed(); - if (singletonMode) { - return currentSingleton != null - ? currentSingleton.getHash() - : 0L; + if (SINGLETON_ENABLED && singletonMode) { + return currentSingleton != null ? currentSingleton.getHash() : 0L; + } + if (FLYWEIGHT_ENABLED && flyweightMode) { + if (cachedFieldOffsets[FIELD_HASH] >= 0) { + return DeltaVarIntCodec.readLongFromSegment(currentSlot, cachedFieldOffsets[FIELD_HASH]); + } + N node = getCurrentNode(); + return node != null ? node.getHash() : 0L; } - return currentNode != null - ? currentNode.getHash() - : 0L; + return currentNode != null ? currentNode.getHash() : 0L; } @Override public NodeKind getKind() { assertNotClosed(); - if (singletonMode) { + if ((FLYWEIGHT_ENABLED && flyweightMode) || (SINGLETON_ENABLED && singletonMode)) { return currentNodeKind; } return getCurrentNode().getKind(); @@ -1236,12 +1723,11 @@ public NodeKind getKind() { /** * Make sure that the transaction is not yet closed when calling this method. - * Uses {@code assert} so the volatile read of {@code isClosed} is eliminated - * when assertions are disabled (the production default), removing a memory - * barrier from every getter on the read hot path. */ public void assertNotClosed() { - assert !isClosed : "Transaction is already closed."; + if (isClosed) { + throw new IllegalStateException("Transaction is already closed."); + } } /** @@ -1262,6 +1748,25 @@ public StorageEngineReader getPageTransaction() { public final void setPageReadTransaction(@Nullable final StorageEngineReader pageReadTransaction) { assertNotClosed(); storageEngineReader = pageReadTransaction; + cachedNodeReader = resolveNodeReader(pageReadTransaction); + cachedWriter = (pageReadTransaction instanceof StorageEngineWriter w) ? w : null; + } + + /** + * Resolve the underlying {@link NodeStorageEngineReader} from a storage engine reader. + * For read-only transactions, this is the reader itself. + * For write transactions (where the reader is a {@link StorageEngineWriter}), + * extracts the delegate reader via {@link StorageEngineWriter#getStorageEngineReader()}. + */ + private static NodeStorageEngineReader resolveNodeReader(@Nullable final StorageEngineReader reader) { + if (reader instanceof NodeStorageEngineReader r) { + return r; + } + if (reader instanceof StorageEngineWriter w + && w.getStorageEngineReader() instanceof NodeStorageEngineReader r) { + return r; + } + return null; } @Override @@ -1276,22 +1781,29 @@ public final long getMaxNodeKey() { * @return structural node instance of current node */ public final StructNode getStructuralNode() { - if (singletonMode && currentSingleton instanceof StructNode structNode) { + // In flyweight mode, materialize if needed + N node = getCurrentNode(); + if (node instanceof StructNode structNode) { return structNode; } + return new io.sirix.node.NullNode(node); + } - // Materialize a structural node only when needed. - final N node = getCurrentNode(); - if (node instanceof final StructNode structNode) { + @Override + public final StructNode getStructuralNodeView() { + if (currentNode instanceof StructNode structNode) { return structNode; } - return new io.sirix.node.NullNode(node); + if (SINGLETON_ENABLED && singletonMode && currentSingleton instanceof StructNode structNode) { + return structNode; + } + return getStructuralNode(); } @Override public boolean moveToNextFollowing() { assertNotClosed(); - // Use cursor getters to avoid unnecessary materialization. + // Use flyweight getters to avoid node materialization while (!hasRightSibling() && hasParent()) { moveToParent(); } @@ -1301,7 +1813,7 @@ public boolean moveToNextFollowing() { @Override public boolean hasNode(final @NonNegative long key) { assertNotClosed(); - // Save current position using cursor-compatible getters. + // Save current position using flyweight-compatible getters final long savedNodeKey = getNodeKey(); final boolean retVal = moveTo(key); // Restore to the saved position @@ -1312,8 +1824,8 @@ public boolean hasNode(final @NonNegative long key) { @Override public boolean hasParent() { assertNotClosed(); - if (singletonMode && currentSingleton != null) { - return currentSingleton.hasParent(); + if (FLYWEIGHT_ENABLED && flyweightMode && cachedFieldOffsets[FIELD_PARENT_KEY] >= 0) { + return getParentKey() != Fixed.NULL_NODE_KEY.getStandardProperty(); } return getCurrentNode().hasParent(); } @@ -1321,7 +1833,7 @@ public boolean hasParent() { @Override public boolean hasFirstChild() { assertNotClosed(); - if (singletonMode) { + if ((SINGLETON_ENABLED && singletonMode) || (FLYWEIGHT_ENABLED && flyweightMode)) { return getFirstChildKey() != Fixed.NULL_NODE_KEY.getStandardProperty(); } return getStructuralNode().hasFirstChild(); @@ -1330,7 +1842,7 @@ public boolean hasFirstChild() { @Override public boolean hasRightSibling() { assertNotClosed(); - if (singletonMode) { + if ((SINGLETON_ENABLED && singletonMode) || (FLYWEIGHT_ENABLED && flyweightMode)) { return getRightSiblingKey() != Fixed.NULL_NODE_KEY.getStandardProperty(); } return getStructuralNode().hasRightSibling(); @@ -1339,37 +1851,46 @@ public boolean hasRightSibling() { @Override public long getRightSiblingKey() { assertNotClosed(); - if (singletonMode && currentSingleton instanceof StructNode sn) { + if (SINGLETON_ENABLED && singletonMode && currentSingleton instanceof StructNode sn) { return sn.getRightSiblingKey(); } + if (FLYWEIGHT_ENABLED && flyweightMode && cachedFieldOffsets[FIELD_RIGHT_SIBLING_KEY] >= 0) { + return DeltaVarIntCodec.decodeDeltaFromSegment(currentSlot, cachedFieldOffsets[FIELD_RIGHT_SIBLING_KEY], currentNodeKey); + } return getStructuralNode().getRightSiblingKey(); } @Override public long getFirstChildKey() { assertNotClosed(); - if (singletonMode && currentSingleton instanceof StructNode sn) { + if (SINGLETON_ENABLED && singletonMode && currentSingleton instanceof StructNode sn) { return sn.getFirstChildKey(); } + if (FLYWEIGHT_ENABLED && flyweightMode && cachedFieldOffsets[FIELD_FIRST_CHILD_KEY] >= 0) { + return DeltaVarIntCodec.decodeDeltaFromSegment(currentSlot, cachedFieldOffsets[FIELD_FIRST_CHILD_KEY], currentNodeKey); + } return getStructuralNode().getFirstChildKey(); } @Override public long getParentKey() { assertNotClosed(); - if (singletonMode && currentSingleton != null) { + if (SINGLETON_ENABLED && singletonMode && currentSingleton != null) { return currentSingleton.getParentKey(); } + if (FLYWEIGHT_ENABLED && flyweightMode && cachedFieldOffsets[FIELD_PARENT_KEY] >= 0) { + return DeltaVarIntCodec.decodeDeltaFromSegment(currentSlot, cachedFieldOffsets[FIELD_PARENT_KEY], currentNodeKey); + } return getCurrentNode().getParentKey(); } @Override public NodeKind getParentKind() { assertNotClosed(); - if (getParentKey() == Fixed.NULL_NODE_KEY.getStandardProperty()) { + final long parentKey = getParentKey(); + if (parentKey == Fixed.NULL_NODE_KEY.getStandardProperty()) { return NodeKind.UNKNOWN; } - // Save current position using cursor-compatible getters. final long savedNodeKey = getNodeKey(); moveToParent(); final NodeKind parentKind = getKind(); @@ -1380,7 +1901,7 @@ public NodeKind getParentKind() { @Override public boolean moveToNext() { assertNotClosed(); - // Use cursor getter directly. + // Use flyweight getter if available if (hasRightSibling()) { // Right sibling node. return moveTo(getRightSiblingKey()); @@ -1392,7 +1913,7 @@ public boolean moveToNext() { @Override public boolean hasLastChild() { assertNotClosed(); - // If it has a first child, it has a last child. + // Use flyweight getter - if it has a first child, it also has a last child return hasFirstChild(); } @@ -1400,7 +1921,7 @@ public boolean hasLastChild() { public NodeKind getLastChildKind() { assertNotClosed(); if (hasLastChild()) { - // Save current position using cursor-compatible getters. + // Save current position using flyweight-compatible getters final long savedNodeKey = getNodeKey(); moveToLastChild(); final NodeKind lastChildKind = getKind(); @@ -1414,7 +1935,7 @@ public NodeKind getLastChildKind() { public NodeKind getFirstChildKind() { assertNotClosed(); if (hasFirstChild()) { - // Save current position using cursor-compatible getters. + // Save current position using flyweight-compatible getters final long savedNodeKey = getNodeKey(); moveToFirstChild(); final NodeKind firstChildKind = getKind(); @@ -1428,7 +1949,7 @@ public NodeKind getFirstChildKind() { public long getLastChildKey() { assertNotClosed(); if (hasLastChild()) { - // Save current position using cursor-compatible getters. + // Save current position using flyweight-compatible getters final long savedNodeKey = getNodeKey(); moveToLastChild(); final long lastChildNodeKey = getNodeKey(); @@ -1441,13 +1962,16 @@ public long getLastChildKey() { @Override public long getChildCount() { assertNotClosed(); + if (FLYWEIGHT_ENABLED && flyweightMode && cachedFieldOffsets[FIELD_CHILD_COUNT] >= 0) { + return DeltaVarIntCodec.decodeSignedFromSegment(currentSlot, cachedFieldOffsets[FIELD_CHILD_COUNT]); + } return getStructuralNode().getChildCount(); } @Override public boolean hasChildren() { assertNotClosed(); - if (singletonMode) { + if ((SINGLETON_ENABLED && singletonMode) || (FLYWEIGHT_ENABLED && flyweightMode)) { return hasFirstChild(); } return getStructuralNode().hasFirstChild(); @@ -1456,6 +1980,9 @@ public boolean hasChildren() { @Override public long getDescendantCount() { assertNotClosed(); + if (FLYWEIGHT_ENABLED && flyweightMode && cachedFieldOffsets[FIELD_DESCENDANT_COUNT] >= 0) { + return DeltaVarIntCodec.decodeSignedFromSegment(currentSlot, cachedFieldOffsets[FIELD_DESCENDANT_COUNT]); + } return getStructuralNode().getDescendantCount(); } @@ -1469,7 +1996,7 @@ public NodeKind getPathKind() { public NodeKind getRightSiblingKind() { assertNotClosed(); if (hasRightSibling()) { - // Save current position using cursor-compatible getters. + // Save current position using flyweight-compatible getters final long savedNodeKey = getNodeKey(); moveToRightSibling(); final NodeKind rightSiblingKind = getKind(); @@ -1494,58 +2021,24 @@ public CommitCredentials getCommitCredentials() { @Override public SirixDeweyID getDeweyID() { assertNotClosed(); - if (singletonMode) { - bindSingletonDeweyBytesIfNeeded(); - return currentSingleton != null - ? currentSingleton.getDeweyID() - : null; - } - return currentNode != null - ? currentNode.getDeweyID() - : null; - } - - private void bindSingletonDeweyBytesIfNeeded() { - if (singletonDeweyBound || currentSingleton == null || !resourceConfig.areDeweyIDsStored || currentPage == null - || currentSlotOffset < 0) { - return; + if (SINGLETON_ENABLED && singletonMode) { + return currentSingleton != null ? currentSingleton.getDeweyID() : null; } - - final byte[] deweyIdBytes = currentPage.getDeweyIdAsByteArray(currentSlotOffset); - switch (currentNodeKind) { - // JSON node kinds - case JSON_DOCUMENT -> ((JsonDocumentRootNode) currentSingleton).setDeweyIDBytes(deweyIdBytes); - case OBJECT -> ((ObjectNode) currentSingleton).setDeweyIDBytes(deweyIdBytes); - case ARRAY -> ((ArrayNode) currentSingleton).setDeweyIDBytes(deweyIdBytes); - case OBJECT_KEY -> ((ObjectKeyNode) currentSingleton).setDeweyIDBytes(deweyIdBytes); - case STRING_VALUE -> ((StringNode) currentSingleton).setDeweyIDBytes(deweyIdBytes); - case OBJECT_STRING_VALUE -> ((ObjectStringNode) currentSingleton).setDeweyIDBytes(deweyIdBytes); - case NUMBER_VALUE -> ((NumberNode) currentSingleton).setDeweyIDBytes(deweyIdBytes); - case OBJECT_NUMBER_VALUE -> ((ObjectNumberNode) currentSingleton).setDeweyIDBytes(deweyIdBytes); - case BOOLEAN_VALUE -> ((BooleanNode) currentSingleton).setDeweyIDBytes(deweyIdBytes); - case OBJECT_BOOLEAN_VALUE -> ((ObjectBooleanNode) currentSingleton).setDeweyIDBytes(deweyIdBytes); - case NULL_VALUE -> ((NullNode) currentSingleton).setDeweyIDBytes(deweyIdBytes); - case OBJECT_NULL_VALUE -> ((ObjectNullNode) currentSingleton).setDeweyIDBytes(deweyIdBytes); - // XML node kinds - case XML_DOCUMENT -> ((XmlDocumentRootNode) currentSingleton).setDeweyIDBytes(deweyIdBytes); - case ELEMENT -> ((ElementNode) currentSingleton).setDeweyIDBytes(deweyIdBytes); - case ATTRIBUTE -> ((AttributeNode) currentSingleton).setDeweyIDBytes(deweyIdBytes); - case NAMESPACE -> ((NamespaceNode) currentSingleton).setDeweyIDBytes(deweyIdBytes); - case TEXT -> ((TextNode) currentSingleton).setDeweyIDBytes(deweyIdBytes); - case COMMENT -> ((CommentNode) currentSingleton).setDeweyIDBytes(deweyIdBytes); - case PROCESSING_INSTRUCTION -> ((PINode) currentSingleton).setDeweyIDBytes(deweyIdBytes); - default -> { - // Unknown singleton kind - harmless. + if (FLYWEIGHT_ENABLED && flyweightMode) { + if (currentDeweyId != null) { + return new SirixDeweyID(currentDeweyId); } + N node = getCurrentNode(); + return node != null ? node.getDeweyID() : null; } - singletonDeweyBound = true; + return currentNode != null ? currentNode.getDeweyID() : null; } @Override public int getPreviousRevisionNumber() { assertNotClosed(); - if (singletonMode && currentSingleton != null) { - return currentSingleton.getPreviousRevisionNumber(); + if (FLYWEIGHT_ENABLED && flyweightMode && cachedFieldOffsets[FIELD_PREV_REVISION] >= 0) { + return DeltaVarIntCodec.decodeSignedFromSegment(currentSlot, cachedFieldOffsets[FIELD_PREV_REVISION]); } return getCurrentNode().getPreviousRevisionNumber(); } @@ -1554,31 +2047,45 @@ public int getPreviousRevisionNumber() { public boolean isClosed() { return isClosed; } - + /** - * Check if singleton mode is currently active. Package-private for testing purposes. + * Check if flyweight mode is currently active. + * Package-private for testing purposes. + * + * @return true if flyweight mode is active (reading directly from MemorySegment) + */ + boolean isFlyweightMode() { + return flyweightMode; + } + + /** + * Check if singleton mode is currently active. + * Package-private for testing purposes. * * @return true if singleton mode is active (using mutable singleton nodes) */ boolean isSingletonMode() { return singletonMode; } - + /** - * Check if zero-allocation mode is active. Package-private for testing purposes. + * Check if zero-allocation mode is active (either flyweight or singleton). + * Package-private for testing purposes. * - * @return true if zero-allocation mode is active + * @return true if any zero-allocation mode is active */ boolean isZeroAllocationMode() { - return singletonMode; + return flyweightMode || singletonMode; } @Override public void close() { if (!isClosed) { - // Release page guard first to allow page eviction. + // Release flyweight state and page guard FIRST to allow page eviction releaseCurrentPageGuard(); - + currentSlot = null; + flyweightMode = false; + // Callback on session to make sure everything is cleaned up. resourceSession.closeReadTransaction(id); diff --git a/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/AbstractNodeTrxImpl.java b/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/AbstractNodeTrxImpl.java index d47ec8959..c2d37283f 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/AbstractNodeTrxImpl.java +++ b/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/AbstractNodeTrxImpl.java @@ -21,9 +21,11 @@ import io.sirix.index.path.summary.PathSummaryWriter; import io.sirix.node.SirixDeweyID; import io.sirix.node.interfaces.DataRecord; +import io.sirix.node.interfaces.FlyweightNode; import io.sirix.node.interfaces.Node; import io.sirix.node.interfaces.StructNode; import io.sirix.node.interfaces.immutable.ImmutableNode; +import io.sirix.page.KeyValueLeafPage; import io.sirix.page.UberPage; import org.checkerframework.checker.index.qual.NonNegative; import org.checkerframework.checker.nullness.qual.Nullable; @@ -370,7 +372,15 @@ protected void checkAccessAndCommit() { } protected final void persistUpdatedRecord(final DataRecord record) { - storageEngineWriter.updateRecordSlot(record, IndexType.DOCUMENT, -1); + if (record instanceof FlyweightNode fn && fn.isWriteSingleton() && fn.getOwnerPage() != null) { + return; // Bound write singleton — mutations already on heap via inlined setters + } + // Ensure the mutated record is stored in the TIL's modified page. + // For records obtained via prepareRecordForModification(), the page is already + // in the TIL and the record is in records[] — this is a safe (redundant) setRecord. + // For records obtained via nodeReadOnlyTrx.getCurrentNode() (e.g., setName/setValue), + // this ensures the page enters the TIL and the record gets into records[]. + storageEngineWriter.persistRecord(record, IndexType.DOCUMENT, -1); } /** @@ -396,6 +406,9 @@ private void intermediateCommitIfRequired() { * @param revNumber revision number */ private void reInstantiate(final @NonNegative int trxID, final @NonNegative int revNumber) { + // Save the current cursor position. getNodeKey() reads from a Java field, always valid. + final long currentNodeKey = nodeReadOnlyTrx.getNodeKey(); + // Reset page transaction to new uber page. resourceSession.closeNodePageWriteTransaction(getId()); storageEngineWriter = @@ -414,6 +427,11 @@ private void reInstantiate(final @NonNegative int trxID, final @NonNegative int updateOperationsOrdered.clear(); reInstantiateIndexes(); + + // Re-read the current node from the new page transaction. + // FlyweightNode getters read from the page MemorySegment; after closing the old transaction, + // that MemorySegment is stale. Re-reading creates a fresh node from the new transaction. + nodeReadOnlyTrx.moveTo(currentNodeKey); } protected abstract AbstractNodeHashing reInstantiateNodeHashing(StorageEngineWriter storageEngineWriter); @@ -442,6 +460,9 @@ public synchronized W rollback() { nodeReadOnlyTrx.assertNotClosed(); + // Save the current cursor position before closing the old page transaction. + final long rollbackNodeKey = nodeReadOnlyTrx.getNodeKey(); + // Reset modification counter. modificationCount = 0L; @@ -470,6 +491,9 @@ public synchronized W rollback() { reInstantiateIndexes(); + // Re-read the current node from the new page transaction (FlyweightNode binding is stale). + nodeReadOnlyTrx.moveTo(rollbackNodeKey); + if (lock != null) { lock.unlock(); } @@ -495,6 +519,9 @@ public W revertTo(final int revision) { nodeReadOnlyTrx.assertNotClosed(); resourceSession.assertAccess(revision); + // Save the current cursor position before closing the old page transaction. + final long revertNodeKey = nodeReadOnlyTrx.getNodeKey(); + // Close current page transaction. final int trxID = getId(); final int revNumber = getRevisionNumber(); diff --git a/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/IndexController.java b/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/IndexController.java index 2e2bf6550..8a257367f 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/IndexController.java +++ b/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/IndexController.java @@ -96,6 +96,15 @@ default boolean hasNameIndex() { return containsIndex(IndexType.NAME); } + /** + * Fast-path check: returns {@code true} if any primitive index (path, name, or CAS) exists. + * Used on the insert hot path to skip expensive moveTo + snapshot operations + * when no indexes are defined. + */ + default boolean hasAnyPrimitiveIndex() { + return hasPathIndex() || hasNameIndex() || hasCASIndex(); + } + /** * Determines if an index of the specified type is available. * diff --git a/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/InternalNodeReadOnlyTrx.java b/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/InternalNodeReadOnlyTrx.java index a52ef5307..beb0de957 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/InternalNodeReadOnlyTrx.java +++ b/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/InternalNodeReadOnlyTrx.java @@ -13,6 +13,14 @@ public interface InternalNodeReadOnlyTrx extends NodeCu StructNode getStructuralNode(); + /** + * Returns a live view of the current structural node without allocating a snapshot. + * When the cursor is in singleton mode, returns the singleton directly (zero-alloc). + * The returned reference must NOT be retained across moveTo/prepareRecordForModification + * calls — extract needed values into local primitives immediately. + */ + StructNode getStructuralNodeView(); + void assertNotClosed(); void setPageReadTransaction(StorageEngineReader trx); diff --git a/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/RecordToRevisionsIndex.java b/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/RecordToRevisionsIndex.java index 067e1ab9c..7eb334337 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/RecordToRevisionsIndex.java +++ b/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/RecordToRevisionsIndex.java @@ -49,6 +49,5 @@ public void addRevisionToRecordToRevisionsIndex(long recordKey) { final RevisionReferencesNode revisionReferencesNode = storageEngineWriter.prepareRecordForModification(recordKey, IndexType.RECORD_TO_REVISIONS, 0); revisionReferencesNode.addRevision(storageEngineWriter.getRevisionNumber()); - storageEngineWriter.updateRecordSlot(revisionReferencesNode, IndexType.RECORD_TO_REVISIONS, 0); } } diff --git a/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/json/JsonNodeFactoryImpl.java b/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/json/JsonNodeFactoryImpl.java index 34861279c..d129c0688 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/json/JsonNodeFactoryImpl.java +++ b/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/json/JsonNodeFactoryImpl.java @@ -1,6 +1,5 @@ package io.sirix.access.trx.node.json; -import io.sirix.access.ResourceConfiguration; import io.sirix.api.StorageEngineWriter; import io.sirix.index.IndexType; import io.sirix.index.path.summary.PathNode; @@ -10,6 +9,7 @@ import io.sirix.node.delegates.NameNodeDelegate; import io.sirix.node.delegates.NodeDelegate; import io.sirix.node.delegates.StructNodeDelegate; +import io.sirix.node.interfaces.DataRecord; import io.sirix.node.json.ArrayNode; import io.sirix.node.json.BooleanNode; import io.sirix.node.json.NullNode; @@ -19,18 +19,22 @@ import io.sirix.node.json.ObjectNode; import io.sirix.node.json.ObjectNullNode; import io.sirix.node.json.ObjectNumberNode; +import io.sirix.node.json.JsonDocumentRootNode; import io.sirix.node.json.ObjectStringNode; import io.sirix.node.json.StringNode; +import io.sirix.page.KeyValueLeafPage; +import io.sirix.page.PageLayout; import io.sirix.page.PathSummaryPage; import io.sirix.settings.Constants; import io.sirix.settings.Fixed; -import io.sirix.settings.StringCompressionType; import io.sirix.utils.NamePageHash; import net.openhft.hashing.LongHashFunction; import io.brackit.query.atomic.QNm; import org.checkerframework.checker.index.qual.NonNegative; import org.checkerframework.checker.nullness.qual.NonNull; +import java.lang.foreign.MemorySegment; + import static java.util.Objects.requireNonNull; /** @@ -40,6 +44,9 @@ */ final class JsonNodeFactoryImpl implements JsonNodeFactory { + /** Cached null node key constant — avoids enum method call in hot path. */ + private static final long NULL_KEY = Fixed.NULL_NODE_KEY.getStandardProperty(); + /** * Hash function used to hash nodes. */ @@ -69,6 +76,7 @@ final class JsonNodeFactoryImpl implements JsonNodeFactory { private final ObjectBooleanNode reusableObjectBooleanNode; private final ObjectNumberNode reusableObjectNumberNode; private final ObjectStringNode reusableObjectStringNode; + private final JsonDocumentRootNode reusableJsonDocumentRootNode; /** * Constructor. @@ -111,177 +119,22 @@ final class JsonNodeFactoryImpl implements JsonNodeFactory { hashFunction, (SirixDeweyID) null); this.reusableObjectStringNode = new ObjectStringNode(0, 0, Constants.NULL_REVISION_NUMBER, revisionNumber, 0, new byte[0], hashFunction, (SirixDeweyID) null, false, null); - } - - private long nextNodeKey() { - return storageEngineWriter.getActualRevisionRootPage().getMaxNodeKeyInDocumentIndex() + 1; - } - - private ObjectNode bindObjectNode(final long nodeKey, final long parentKey, final long leftSibKey, - final long rightSibKey, final SirixDeweyID id) { - final ObjectNode node = reusableObjectNode; - node.setNodeKey(nodeKey); - node.setParentKey(parentKey); - node.setPreviousRevision(Constants.NULL_REVISION_NUMBER); - node.setLastModifiedRevision(revisionNumber); - node.setRightSiblingKey(rightSibKey); - node.setLeftSiblingKey(leftSibKey); - node.setFirstChildKey(Fixed.NULL_NODE_KEY.getStandardProperty()); - node.setLastChildKey(Fixed.NULL_NODE_KEY.getStandardProperty()); - node.setChildCount(0); - node.setDescendantCount(0); - node.setHash(0); - node.setDeweyID(id); - return node; - } - - private ArrayNode bindArrayNode(final long nodeKey, final long parentKey, final long leftSibKey, - final long rightSibKey, final long pathNodeKey, final SirixDeweyID id) { - final ArrayNode node = reusableArrayNode; - node.setNodeKey(nodeKey); - node.setParentKey(parentKey); - node.setPathNodeKey(pathNodeKey); - node.setPreviousRevision(Constants.NULL_REVISION_NUMBER); - node.setLastModifiedRevision(revisionNumber); - node.setRightSiblingKey(rightSibKey); - node.setLeftSiblingKey(leftSibKey); - node.setFirstChildKey(Fixed.NULL_NODE_KEY.getStandardProperty()); - node.setLastChildKey(Fixed.NULL_NODE_KEY.getStandardProperty()); - node.setChildCount(0); - node.setDescendantCount(0); - node.setHash(0); - node.setDeweyID(id); - return node; - } - - private ObjectKeyNode bindObjectKeyNode(final long nodeKey, final long parentKey, final long leftSibKey, - final long rightSibKey, final long pathNodeKey, final int nameKey, final String name, final long objectValueKey, - final SirixDeweyID id) { - final ObjectKeyNode node = reusableObjectKeyNode; - node.setNodeKey(nodeKey); - node.setParentKey(parentKey); - node.setPathNodeKey(pathNodeKey); - node.setPreviousRevision(Constants.NULL_REVISION_NUMBER); - node.setLastModifiedRevision(revisionNumber); - node.setRightSiblingKey(rightSibKey); - node.setLeftSiblingKey(leftSibKey); - node.setFirstChildKey(objectValueKey); - node.setNameKey(nameKey); - node.setName(name); - node.setDescendantCount(0); - node.setHash(0); - node.setDeweyID(id); - return node; - } - - private NullNode bindNullNode(final long nodeKey, final long parentKey, final long leftSibKey, final long rightSibKey, - final SirixDeweyID id) { - final NullNode node = reusableNullNode; - node.setNodeKey(nodeKey); - node.setParentKey(parentKey); - node.setPreviousRevision(Constants.NULL_REVISION_NUMBER); - node.setLastModifiedRevision(revisionNumber); - node.setRightSiblingKey(rightSibKey); - node.setLeftSiblingKey(leftSibKey); - node.setHash(0); - node.setDeweyID(id); - return node; - } - - private BooleanNode bindBooleanNode(final long nodeKey, final long parentKey, final long leftSibKey, - final long rightSibKey, final boolean boolValue, final SirixDeweyID id) { - final BooleanNode node = reusableBooleanNode; - node.setNodeKey(nodeKey); - node.setParentKey(parentKey); - node.setPreviousRevision(Constants.NULL_REVISION_NUMBER); - node.setLastModifiedRevision(revisionNumber); - node.setRightSiblingKey(rightSibKey); - node.setLeftSiblingKey(leftSibKey); - node.setHash(0); - node.setValue(boolValue); - node.setDeweyID(id); - return node; - } - - private NumberNode bindNumberNode(final long nodeKey, final long parentKey, final long leftSibKey, - final long rightSibKey, final Number value, final SirixDeweyID id) { - final NumberNode node = reusableNumberNode; - node.setNodeKey(nodeKey); - node.setParentKey(parentKey); - node.setPreviousRevision(Constants.NULL_REVISION_NUMBER); - node.setLastModifiedRevision(revisionNumber); - node.setRightSiblingKey(rightSibKey); - node.setLeftSiblingKey(leftSibKey); - node.setHash(0); - node.setValue(value); - node.setDeweyID(id); - return node; - } - - private StringNode bindStringNode(final long nodeKey, final long parentKey, final long leftSibKey, - final long rightSibKey, final byte[] value, final boolean isCompressed, final byte[] fsstSymbolTable, - final SirixDeweyID id) { - final StringNode node = reusableStringNode; - node.setNodeKey(nodeKey); - node.setParentKey(parentKey); - node.setPreviousRevision(Constants.NULL_REVISION_NUMBER); - node.setLastModifiedRevision(revisionNumber); - node.setRightSiblingKey(rightSibKey); - node.setLeftSiblingKey(leftSibKey); - node.setHash(0); - node.setRawValue(value, isCompressed, fsstSymbolTable); - node.setDeweyID(id); - return node; - } - private ObjectNullNode bindObjectNullNode(final long nodeKey, final long parentKey, final SirixDeweyID id) { - final ObjectNullNode node = reusableObjectNullNode; - node.setNodeKey(nodeKey); - node.setParentKey(parentKey); - node.setPreviousRevision(Constants.NULL_REVISION_NUMBER); - node.setLastModifiedRevision(revisionNumber); - node.setHash(0); - node.setDeweyID(id); - return node; - } - - private ObjectBooleanNode bindObjectBooleanNode(final long nodeKey, final long parentKey, final boolean boolValue, - final SirixDeweyID id) { - final ObjectBooleanNode node = reusableObjectBooleanNode; - node.setNodeKey(nodeKey); - node.setParentKey(parentKey); - node.setPreviousRevision(Constants.NULL_REVISION_NUMBER); - node.setLastModifiedRevision(revisionNumber); - node.setHash(0); - node.setValue(boolValue); - node.setDeweyID(id); - return node; - } - - private ObjectNumberNode bindObjectNumberNode(final long nodeKey, final long parentKey, final Number value, - final SirixDeweyID id) { - final ObjectNumberNode node = reusableObjectNumberNode; - node.setNodeKey(nodeKey); - node.setParentKey(parentKey); - node.setPreviousRevision(Constants.NULL_REVISION_NUMBER); - node.setLastModifiedRevision(revisionNumber); - node.setHash(0); - node.setValue(value); - node.setDeweyID(id); - return node; - } - - private ObjectStringNode bindObjectStringNode(final long nodeKey, final long parentKey, final byte[] value, - final boolean isCompressed, final byte[] fsstSymbolTable, final SirixDeweyID id) { - final ObjectStringNode node = reusableObjectStringNode; - node.setNodeKey(nodeKey); - node.setParentKey(parentKey); - node.setPreviousRevision(Constants.NULL_REVISION_NUMBER); - node.setLastModifiedRevision(revisionNumber); - node.setHash(0); - node.setRawValue(value, isCompressed, fsstSymbolTable); - node.setDeweyID(id); - return node; + this.reusableJsonDocumentRootNode = new JsonDocumentRootNode(0, hashFunction); + + // Mark all singletons as write singletons so setRecord skips records[] storage. + reusableJsonDocumentRootNode.setWriteSingleton(true); + reusableObjectNode.setWriteSingleton(true); + reusableArrayNode.setWriteSingleton(true); + reusableObjectKeyNode.setWriteSingleton(true); + reusableNullNode.setWriteSingleton(true); + reusableBooleanNode.setWriteSingleton(true); + reusableNumberNode.setWriteSingleton(true); + reusableStringNode.setWriteSingleton(true); + reusableObjectNullNode.setWriteSingleton(true); + reusableObjectBooleanNode.setWriteSingleton(true); + reusableObjectNumberNode.setWriteSingleton(true); + reusableObjectStringNode.setWriteSingleton(true); } @Override @@ -310,110 +163,338 @@ public PathNode createPathNode(final @NonNegative long parentKey, final long lef @Override public ArrayNode createJsonArrayNode(long parentKey, long leftSibKey, long rightSibKey, long pathNodeKey, SirixDeweyID id) { - final long nodeKey = nextNodeKey(); - final ArrayNode node = bindArrayNode(nodeKey, parentKey, leftSibKey, rightSibKey, pathNodeKey, id); - return storageEngineWriter.createRecord(node, IndexType.DOCUMENT, -1); + storageEngineWriter.allocateForDocumentCreation(); + final KeyValueLeafPage kvl = storageEngineWriter.getAllocKvl(); + final long nodeKey = storageEngineWriter.getAllocNodeKey(); + final int slotOffset = storageEngineWriter.getAllocSlotOffset(); + final byte[] deweyIdBytes = (id != null && kvl.areDeweyIDsStored()) ? id.toBytes() : null; + final int deweyIdLen = deweyIdBytes != null ? deweyIdBytes.length : 0; + final long absOffset = kvl.prepareHeapForDirectWrite( + reusableArrayNode.estimateSerializedSize(), deweyIdLen); + final int recordBytes = ArrayNode.writeNewRecord(kvl.getSlottedPage(), absOffset, + reusableArrayNode.getHeapOffsets(), nodeKey, parentKey, rightSibKey, leftSibKey, + NULL_KEY, NULL_KEY, pathNodeKey, + Constants.NULL_REVISION_NUMBER, revisionNumber, 0, 0, 0); + kvl.completeDirectWrite(NodeKind.ARRAY.getId(), nodeKey, slotOffset, recordBytes, deweyIdBytes); + reusableArrayNode.bind(kvl.getSlottedPage(), absOffset, nodeKey, slotOffset); + reusableArrayNode.setOwnerPage(kvl); + reusableArrayNode.setDeweyIDAfterCreation(id, deweyIdBytes); + return reusableArrayNode; } @Override public ObjectNode createJsonObjectNode(long parentKey, long leftSibKey, long rightSibKey, SirixDeweyID id) { - final long nodeKey = nextNodeKey(); - final ObjectNode node = bindObjectNode(nodeKey, parentKey, leftSibKey, rightSibKey, id); - return storageEngineWriter.createRecord(node, IndexType.DOCUMENT, -1); + storageEngineWriter.allocateForDocumentCreation(); + final KeyValueLeafPage kvl = storageEngineWriter.getAllocKvl(); + final long nodeKey = storageEngineWriter.getAllocNodeKey(); + final int slotOffset = storageEngineWriter.getAllocSlotOffset(); + final byte[] deweyIdBytes = (id != null && kvl.areDeweyIDsStored()) ? id.toBytes() : null; + final int deweyIdLen = deweyIdBytes != null ? deweyIdBytes.length : 0; + final long absOffset = kvl.prepareHeapForDirectWrite( + reusableObjectNode.estimateSerializedSize(), deweyIdLen); + final int recordBytes = ObjectNode.writeNewRecord(kvl.getSlottedPage(), absOffset, + reusableObjectNode.getHeapOffsets(), nodeKey, parentKey, rightSibKey, leftSibKey, + NULL_KEY, NULL_KEY, + Constants.NULL_REVISION_NUMBER, revisionNumber, 0, 0, 0); + kvl.completeDirectWrite(NodeKind.OBJECT.getId(), nodeKey, slotOffset, recordBytes, deweyIdBytes); + reusableObjectNode.bind(kvl.getSlottedPage(), absOffset, nodeKey, slotOffset); + reusableObjectNode.setOwnerPage(kvl); + reusableObjectNode.setDeweyIDAfterCreation(id, deweyIdBytes); + return reusableObjectNode; } @Override public NullNode createJsonNullNode(long parentKey, long leftSibKey, long rightSibKey, SirixDeweyID id) { - final long nodeKey = nextNodeKey(); - final NullNode node = bindNullNode(nodeKey, parentKey, leftSibKey, rightSibKey, id); - return storageEngineWriter.createRecord(node, IndexType.DOCUMENT, -1); + storageEngineWriter.allocateForDocumentCreation(); + final KeyValueLeafPage kvl = storageEngineWriter.getAllocKvl(); + final long nodeKey = storageEngineWriter.getAllocNodeKey(); + final int slotOffset = storageEngineWriter.getAllocSlotOffset(); + final byte[] deweyIdBytes = (id != null && kvl.areDeweyIDsStored()) ? id.toBytes() : null; + final int deweyIdLen = deweyIdBytes != null ? deweyIdBytes.length : 0; + final long absOffset = kvl.prepareHeapForDirectWrite( + reusableNullNode.estimateSerializedSize(), deweyIdLen); + final int recordBytes = NullNode.writeNewRecord(kvl.getSlottedPage(), absOffset, + reusableNullNode.getHeapOffsets(), nodeKey, parentKey, rightSibKey, leftSibKey, + Constants.NULL_REVISION_NUMBER, revisionNumber); + kvl.completeDirectWrite(NodeKind.NULL_VALUE.getId(), nodeKey, slotOffset, recordBytes, deweyIdBytes); + reusableNullNode.bind(kvl.getSlottedPage(), absOffset, nodeKey, slotOffset); + reusableNullNode.setOwnerPage(kvl); + reusableNullNode.setDeweyIDAfterCreation(id, deweyIdBytes); + return reusableNullNode; } @Override public ObjectKeyNode createJsonObjectKeyNode(long parentKey, long leftSibKey, long rightSibKey, long pathNodeKey, String name, long objectValueKey, SirixDeweyID id) { final int localNameKey = storageEngineWriter.createNameKey(name, NodeKind.OBJECT_KEY); - final long nodeKey = nextNodeKey(); - final ObjectKeyNode node = bindObjectKeyNode(nodeKey, parentKey, leftSibKey, rightSibKey, pathNodeKey, localNameKey, - name, objectValueKey, id); - return storageEngineWriter.createRecord(node, IndexType.DOCUMENT, -1); + storageEngineWriter.allocateForDocumentCreation(); + final KeyValueLeafPage kvl = storageEngineWriter.getAllocKvl(); + final long nodeKey = storageEngineWriter.getAllocNodeKey(); + final int slotOffset = storageEngineWriter.getAllocSlotOffset(); + final byte[] deweyIdBytes = (id != null && kvl.areDeweyIDsStored()) ? id.toBytes() : null; + final int deweyIdLen = deweyIdBytes != null ? deweyIdBytes.length : 0; + final long absOffset = kvl.prepareHeapForDirectWrite( + reusableObjectKeyNode.estimateSerializedSize(), deweyIdLen); + final int recordBytes = ObjectKeyNode.writeNewRecord(kvl.getSlottedPage(), absOffset, + reusableObjectKeyNode.getHeapOffsets(), nodeKey, parentKey, rightSibKey, leftSibKey, + objectValueKey, localNameKey, pathNodeKey, + Constants.NULL_REVISION_NUMBER, revisionNumber, 0, 0); + kvl.completeDirectWrite(NodeKind.OBJECT_KEY.getId(), nodeKey, slotOffset, recordBytes, deweyIdBytes); + reusableObjectKeyNode.bind(kvl.getSlottedPage(), absOffset, nodeKey, slotOffset); + reusableObjectKeyNode.setOwnerPage(kvl); + reusableObjectKeyNode.setDeweyIDAfterCreation(id, deweyIdBytes); + return reusableObjectKeyNode; } @Override public StringNode createJsonStringNode(long parentKey, long leftSibKey, long rightSibKey, byte[] value, boolean doCompress, SirixDeweyID id) { - final long nodeKey = nextNodeKey(); - - // For FSST, page-level symbol tables are required for decoding. - // Until symbol table plumbing is complete, keep stored values uncompressed. - final ResourceConfiguration config = storageEngineWriter.getResourceSession().getResourceConfig(); - final boolean shouldUseCompression = doCompress && config.stringCompressionType == StringCompressionType.FSST; - if (shouldUseCompression) { - // Intentionally not compressing here: no symbol table is available on this path yet. - } - final boolean isCompressed = false; - - final StringNode node = bindStringNode(nodeKey, parentKey, leftSibKey, rightSibKey, value, isCompressed, null, id); - return storageEngineWriter.createRecord(node, IndexType.DOCUMENT, -1); + storageEngineWriter.allocateForDocumentCreation(); + final KeyValueLeafPage kvl = storageEngineWriter.getAllocKvl(); + final long nodeKey = storageEngineWriter.getAllocNodeKey(); + final int slotOffset = storageEngineWriter.getAllocSlotOffset(); + final byte[] deweyIdBytes = (id != null && kvl.areDeweyIDsStored()) ? id.toBytes() : null; + final int deweyIdLen = deweyIdBytes != null ? deweyIdBytes.length : 0; + final long absOffset = kvl.prepareHeapForDirectWrite( + 55 + value.length, deweyIdLen); + final int recordBytes = StringNode.writeNewRecord(kvl.getSlottedPage(), absOffset, + reusableStringNode.getHeapOffsets(), nodeKey, parentKey, rightSibKey, leftSibKey, + Constants.NULL_REVISION_NUMBER, revisionNumber, value, false); + kvl.completeDirectWrite(NodeKind.STRING_VALUE.getId(), nodeKey, slotOffset, recordBytes, deweyIdBytes); + reusableStringNode.bind(kvl.getSlottedPage(), absOffset, nodeKey, slotOffset); + reusableStringNode.setOwnerPage(kvl); + reusableStringNode.setDeweyIDAfterCreation(id, deweyIdBytes); + return reusableStringNode; } @Override public BooleanNode createJsonBooleanNode(long parentKey, long leftSibKey, long rightSibKey, boolean boolValue, SirixDeweyID id) { - final long nodeKey = nextNodeKey(); - final BooleanNode node = bindBooleanNode(nodeKey, parentKey, leftSibKey, rightSibKey, boolValue, id); - return storageEngineWriter.createRecord(node, IndexType.DOCUMENT, -1); + storageEngineWriter.allocateForDocumentCreation(); + final KeyValueLeafPage kvl = storageEngineWriter.getAllocKvl(); + final long nodeKey = storageEngineWriter.getAllocNodeKey(); + final int slotOffset = storageEngineWriter.getAllocSlotOffset(); + final byte[] deweyIdBytes = (id != null && kvl.areDeweyIDsStored()) ? id.toBytes() : null; + final int deweyIdLen = deweyIdBytes != null ? deweyIdBytes.length : 0; + final long absOffset = kvl.prepareHeapForDirectWrite( + reusableBooleanNode.estimateSerializedSize(), deweyIdLen); + final int recordBytes = BooleanNode.writeNewRecord(kvl.getSlottedPage(), absOffset, + reusableBooleanNode.getHeapOffsets(), nodeKey, parentKey, rightSibKey, leftSibKey, + Constants.NULL_REVISION_NUMBER, revisionNumber, boolValue); + kvl.completeDirectWrite(NodeKind.BOOLEAN_VALUE.getId(), nodeKey, slotOffset, recordBytes, deweyIdBytes); + reusableBooleanNode.bind(kvl.getSlottedPage(), absOffset, nodeKey, slotOffset); + reusableBooleanNode.setOwnerPage(kvl); + reusableBooleanNode.setDeweyIDAfterCreation(id, deweyIdBytes); + return reusableBooleanNode; } @Override public NumberNode createJsonNumberNode(long parentKey, long leftSibKey, long rightSibKey, Number value, SirixDeweyID id) { - final long nodeKey = nextNodeKey(); - final NumberNode node = bindNumberNode(nodeKey, parentKey, leftSibKey, rightSibKey, value, id); - return storageEngineWriter.createRecord(node, IndexType.DOCUMENT, -1); + storageEngineWriter.allocateForDocumentCreation(); + final KeyValueLeafPage kvl = storageEngineWriter.getAllocKvl(); + final long nodeKey = storageEngineWriter.getAllocNodeKey(); + final int slotOffset = storageEngineWriter.getAllocSlotOffset(); + final byte[] deweyIdBytes = (id != null && kvl.areDeweyIDsStored()) ? id.toBytes() : null; + final int deweyIdLen = deweyIdBytes != null ? deweyIdBytes.length : 0; + final long absOffset = kvl.prepareHeapForDirectWrite( + reusableNumberNode.estimateSerializedSize(), deweyIdLen); + final int recordBytes = NumberNode.writeNewRecord(kvl.getSlottedPage(), absOffset, + reusableNumberNode.getHeapOffsets(), nodeKey, parentKey, rightSibKey, leftSibKey, + Constants.NULL_REVISION_NUMBER, revisionNumber, value); + kvl.completeDirectWrite(NodeKind.NUMBER_VALUE.getId(), nodeKey, slotOffset, recordBytes, deweyIdBytes); + reusableNumberNode.bind(kvl.getSlottedPage(), absOffset, nodeKey, slotOffset); + reusableNumberNode.setOwnerPage(kvl); + reusableNumberNode.setDeweyIDAfterCreation(id, deweyIdBytes); + return reusableNumberNode; } @Override public ObjectNullNode createJsonObjectNullNode(long parentKey, SirixDeweyID id) { - final long nodeKey = nextNodeKey(); - final ObjectNullNode node = bindObjectNullNode(nodeKey, parentKey, id); - return storageEngineWriter.createRecord(node, IndexType.DOCUMENT, -1); + storageEngineWriter.allocateForDocumentCreation(); + final KeyValueLeafPage kvl = storageEngineWriter.getAllocKvl(); + final long nodeKey = storageEngineWriter.getAllocNodeKey(); + final int slotOffset = storageEngineWriter.getAllocSlotOffset(); + final byte[] deweyIdBytes = (id != null && kvl.areDeweyIDsStored()) ? id.toBytes() : null; + final int deweyIdLen = deweyIdBytes != null ? deweyIdBytes.length : 0; + final long absOffset = kvl.prepareHeapForDirectWrite( + reusableObjectNullNode.estimateSerializedSize(), deweyIdLen); + final int recordBytes = ObjectNullNode.writeNewRecord(kvl.getSlottedPage(), absOffset, + reusableObjectNullNode.getHeapOffsets(), nodeKey, parentKey, + Constants.NULL_REVISION_NUMBER, revisionNumber); + kvl.completeDirectWrite(NodeKind.OBJECT_NULL_VALUE.getId(), nodeKey, slotOffset, recordBytes, deweyIdBytes); + reusableObjectNullNode.bind(kvl.getSlottedPage(), absOffset, nodeKey, slotOffset); + reusableObjectNullNode.setOwnerPage(kvl); + reusableObjectNullNode.setDeweyIDAfterCreation(id, deweyIdBytes); + return reusableObjectNullNode; } @Override public ObjectStringNode createJsonObjectStringNode(long parentKey, byte[] value, boolean doCompress, SirixDeweyID id) { - final long nodeKey = nextNodeKey(); - - // For FSST, page-level symbol tables are required for decoding. - // Until symbol table plumbing is complete, keep stored values uncompressed. - final ResourceConfiguration config = storageEngineWriter.getResourceSession().getResourceConfig(); - final boolean shouldUseCompression = doCompress && config.stringCompressionType == StringCompressionType.FSST; - if (shouldUseCompression) { - // Intentionally not compressing here: no symbol table is available on this path yet. - } - final boolean isCompressed = false; - - final ObjectStringNode node = bindObjectStringNode(nodeKey, parentKey, value, isCompressed, null, id); - return storageEngineWriter.createRecord(node, IndexType.DOCUMENT, -1); + storageEngineWriter.allocateForDocumentCreation(); + final KeyValueLeafPage kvl = storageEngineWriter.getAllocKvl(); + final long nodeKey = storageEngineWriter.getAllocNodeKey(); + final int slotOffset = storageEngineWriter.getAllocSlotOffset(); + final byte[] deweyIdBytes = (id != null && kvl.areDeweyIDsStored()) ? id.toBytes() : null; + final int deweyIdLen = deweyIdBytes != null ? deweyIdBytes.length : 0; + final long absOffset = kvl.prepareHeapForDirectWrite( + 55 + value.length, deweyIdLen); + final int recordBytes = ObjectStringNode.writeNewRecord(kvl.getSlottedPage(), absOffset, + reusableObjectStringNode.getHeapOffsets(), nodeKey, parentKey, + Constants.NULL_REVISION_NUMBER, revisionNumber, value, false); + kvl.completeDirectWrite(NodeKind.OBJECT_STRING_VALUE.getId(), nodeKey, slotOffset, recordBytes, deweyIdBytes); + reusableObjectStringNode.bind(kvl.getSlottedPage(), absOffset, nodeKey, slotOffset); + reusableObjectStringNode.setOwnerPage(kvl); + reusableObjectStringNode.setDeweyIDAfterCreation(id, deweyIdBytes); + return reusableObjectStringNode; } @Override public ObjectBooleanNode createJsonObjectBooleanNode(long parentKey, boolean boolValue, SirixDeweyID id) { - final long nodeKey = nextNodeKey(); - final ObjectBooleanNode node = bindObjectBooleanNode(nodeKey, parentKey, boolValue, id); - return storageEngineWriter.createRecord(node, IndexType.DOCUMENT, -1); + storageEngineWriter.allocateForDocumentCreation(); + final KeyValueLeafPage kvl = storageEngineWriter.getAllocKvl(); + final long nodeKey = storageEngineWriter.getAllocNodeKey(); + final int slotOffset = storageEngineWriter.getAllocSlotOffset(); + final byte[] deweyIdBytes = (id != null && kvl.areDeweyIDsStored()) ? id.toBytes() : null; + final int deweyIdLen = deweyIdBytes != null ? deweyIdBytes.length : 0; + final long absOffset = kvl.prepareHeapForDirectWrite( + reusableObjectBooleanNode.estimateSerializedSize(), deweyIdLen); + final int recordBytes = ObjectBooleanNode.writeNewRecord(kvl.getSlottedPage(), absOffset, + reusableObjectBooleanNode.getHeapOffsets(), nodeKey, parentKey, + Constants.NULL_REVISION_NUMBER, revisionNumber, boolValue); + kvl.completeDirectWrite(NodeKind.OBJECT_BOOLEAN_VALUE.getId(), nodeKey, slotOffset, recordBytes, deweyIdBytes); + reusableObjectBooleanNode.bind(kvl.getSlottedPage(), absOffset, nodeKey, slotOffset); + reusableObjectBooleanNode.setOwnerPage(kvl); + reusableObjectBooleanNode.setDeweyIDAfterCreation(id, deweyIdBytes); + return reusableObjectBooleanNode; } @Override public ObjectNumberNode createJsonObjectNumberNode(long parentKey, Number value, SirixDeweyID id) { - final long nodeKey = nextNodeKey(); - final ObjectNumberNode node = bindObjectNumberNode(nodeKey, parentKey, value, id); - return storageEngineWriter.createRecord(node, IndexType.DOCUMENT, -1); + storageEngineWriter.allocateForDocumentCreation(); + final KeyValueLeafPage kvl = storageEngineWriter.getAllocKvl(); + final long nodeKey = storageEngineWriter.getAllocNodeKey(); + final int slotOffset = storageEngineWriter.getAllocSlotOffset(); + final byte[] deweyIdBytes = (id != null && kvl.areDeweyIDsStored()) ? id.toBytes() : null; + final int deweyIdLen = deweyIdBytes != null ? deweyIdBytes.length : 0; + final long absOffset = kvl.prepareHeapForDirectWrite( + reusableObjectNumberNode.estimateSerializedSize(), deweyIdLen); + final int recordBytes = ObjectNumberNode.writeNewRecord(kvl.getSlottedPage(), absOffset, + reusableObjectNumberNode.getHeapOffsets(), nodeKey, parentKey, + Constants.NULL_REVISION_NUMBER, revisionNumber, value); + kvl.completeDirectWrite(NodeKind.OBJECT_NUMBER_VALUE.getId(), nodeKey, slotOffset, recordBytes, deweyIdBytes); + reusableObjectNumberNode.bind(kvl.getSlottedPage(), absOffset, nodeKey, slotOffset); + reusableObjectNumberNode.setOwnerPage(kvl); + reusableObjectNumberNode.setDeweyIDAfterCreation(id, deweyIdBytes); + return reusableObjectNumberNode; } @Override public DeweyIDNode createDeweyIdNode(long nodeKey, @NonNull SirixDeweyID id) { return storageEngineWriter.createRecord(new DeweyIDNode(nodeKey, id), IndexType.DEWEYID_TO_RECORDID, 0); } + + /** + * Bind the correct write singleton to a slotted page slot for zero-allocation modification. + * Reads the nodeKindId from the page directory, selects the matching singleton, unbinds if + * currently bound elsewhere, binds to the slot, and propagates DeweyID. + * + * @param page the KeyValueLeafPage containing the slotted page + * @param offset the slot index (0-1023) + * @param nodeKey the record key + * @return the bound write singleton, or null if the slot is not a JSON node type + */ + DataRecord bindWriteSingleton(final KeyValueLeafPage page, final int offset, final long nodeKey) { + final MemorySegment slottedPage = page.getSlottedPage(); + if (slottedPage == null || !PageLayout.isSlotPopulated(slottedPage, offset)) { + return null; + } + final int nodeKindId = PageLayout.getDirNodeKindId(slottedPage, offset); + final int heapOffset = PageLayout.getDirHeapOffset(slottedPage, offset); + final long recordBase = PageLayout.heapAbsoluteOffset(heapOffset); + final byte[] deweyIdBytes = page.getDeweyIdAsByteArray(offset); + + // Concrete-type switch eliminates 3 itable stubs per bind (bind, setDeweyIDBytes, setOwnerPage). + // Each case is monomorphic — JVM can inline directly. + // setDeweyIDBytes stores raw bytes lazily (no SirixDeweyID parsing). + // No setOwnerPage(null) needed — setDeweyIDBytes doesn't trigger resize. + return switch (nodeKindId) { + case 24 -> { // OBJECT + reusableObjectNode.bind(slottedPage, recordBase, nodeKey, offset); + reusableObjectNode.setDeweyIDBytes(deweyIdBytes); + reusableObjectNode.setOwnerPage(page); + yield reusableObjectNode; + } + case 25 -> { // ARRAY + reusableArrayNode.bind(slottedPage, recordBase, nodeKey, offset); + reusableArrayNode.setDeweyIDBytes(deweyIdBytes); + reusableArrayNode.setOwnerPage(page); + yield reusableArrayNode; + } + case 26 -> { // OBJECT_KEY + reusableObjectKeyNode.bind(slottedPage, recordBase, nodeKey, offset); + reusableObjectKeyNode.setDeweyIDBytes(deweyIdBytes); + reusableObjectKeyNode.setOwnerPage(page); + yield reusableObjectKeyNode; + } + case 27 -> { // BOOLEAN_VALUE + reusableBooleanNode.bind(slottedPage, recordBase, nodeKey, offset); + reusableBooleanNode.setDeweyIDBytes(deweyIdBytes); + reusableBooleanNode.setOwnerPage(page); + yield reusableBooleanNode; + } + case 28 -> { // NUMBER_VALUE + reusableNumberNode.bind(slottedPage, recordBase, nodeKey, offset); + reusableNumberNode.setDeweyIDBytes(deweyIdBytes); + reusableNumberNode.setOwnerPage(page); + yield reusableNumberNode; + } + case 29 -> { // NULL_VALUE + reusableNullNode.bind(slottedPage, recordBase, nodeKey, offset); + reusableNullNode.setDeweyIDBytes(deweyIdBytes); + reusableNullNode.setOwnerPage(page); + yield reusableNullNode; + } + case 30 -> { // STRING_VALUE + reusableStringNode.bind(slottedPage, recordBase, nodeKey, offset); + reusableStringNode.setDeweyIDBytes(deweyIdBytes); + reusableStringNode.setOwnerPage(page); + reusableStringNode.setFsstSymbolTable(page.getFsstSymbolTable()); + yield reusableStringNode; + } + case 31 -> { // JSON_DOCUMENT + reusableJsonDocumentRootNode.bind(slottedPage, recordBase, nodeKey, offset); + reusableJsonDocumentRootNode.setDeweyIDBytes(deweyIdBytes); + reusableJsonDocumentRootNode.setOwnerPage(page); + yield reusableJsonDocumentRootNode; + } + case 40 -> { // OBJECT_STRING_VALUE + reusableObjectStringNode.bind(slottedPage, recordBase, nodeKey, offset); + reusableObjectStringNode.setDeweyIDBytes(deweyIdBytes); + reusableObjectStringNode.setOwnerPage(page); + reusableObjectStringNode.setFsstSymbolTable(page.getFsstSymbolTable()); + yield reusableObjectStringNode; + } + case 41 -> { // OBJECT_BOOLEAN_VALUE + reusableObjectBooleanNode.bind(slottedPage, recordBase, nodeKey, offset); + reusableObjectBooleanNode.setDeweyIDBytes(deweyIdBytes); + reusableObjectBooleanNode.setOwnerPage(page); + yield reusableObjectBooleanNode; + } + case 42 -> { // OBJECT_NUMBER_VALUE + reusableObjectNumberNode.bind(slottedPage, recordBase, nodeKey, offset); + reusableObjectNumberNode.setDeweyIDBytes(deweyIdBytes); + reusableObjectNumberNode.setOwnerPage(page); + yield reusableObjectNumberNode; + } + case 43 -> { // OBJECT_NULL_VALUE + reusableObjectNullNode.bind(slottedPage, recordBase, nodeKey, offset); + reusableObjectNullNode.setDeweyIDBytes(deweyIdBytes); + reusableObjectNullNode.setOwnerPage(page); + yield reusableObjectNullNode; + } + default -> null; + }; + } } diff --git a/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/json/JsonNodeHashing.java b/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/json/JsonNodeHashing.java index 1f8a17889..61de27ca4 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/json/JsonNodeHashing.java +++ b/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/json/JsonNodeHashing.java @@ -26,7 +26,7 @@ final class JsonNodeHashing extends AbstractNodeHashing value) { @Override public JsonNodeTrx insertStringValueAsFirstChild(final String value) { requireNonNull(value); - final byte[] textValue = getBytes(value); - return insertPrimitiveAsChild( - (parentKey, id) -> nodeFactory.createJsonObjectStringNode(parentKey, textValue, useTextCompression, id), - (parentKey, leftSib, rightSib, id) -> nodeFactory.createJsonStringNode(parentKey, leftSib, rightSib, textValue, - useTextCompression, id), - true, true); + return insertPrimitiveAsChild(PrimitiveNodeType.STRING, getBytes(value), null, false, true, true); } @Override public JsonNodeTrx insertStringValueAsLastChild(final String value) { requireNonNull(value); - final byte[] textValue = getBytes(value); - return insertPrimitiveAsChild( - (parentKey, id) -> nodeFactory.createJsonObjectStringNode(parentKey, textValue, useTextCompression, id), - (parentKey, leftSib, rightSib, id) -> nodeFactory.createJsonStringNode(parentKey, leftSib, rightSib, textValue, - useTextCompression, id), - true, false); + return insertPrimitiveAsChild(PrimitiveNodeType.STRING, getBytes(value), null, false, true, false); } private long getPathNodeKey(StructNode structNode) { @@ -1293,56 +1333,50 @@ private long getPathNodeKey(StructNode structNode) { return pathNodeKey; } - private void adaptNodesAndHashesForInsertAsChild(final ImmutableJsonNode node) { - // Adapt local nodes and hashes. - nodeReadOnlyTrx.setCurrentNode(node); - adaptForInsert((StructNode) node); - nodeReadOnlyTrx.setCurrentNode(node); - nodeHashing.adaptHashesWithAdd(); + private void adaptNodesAndHashesForInsertAsChild(final long nodeKey, final long parentKey, + final long leftSibKey, final long rightSibKey) { + // Pass structural keys directly — eliminates moveTo before adaptForInsert. + // Old code did: moveTo(nodeKey) → adaptForInsert(getStructuralNodeView()) → moveTo(nodeKey) → hash. + // New code: adaptForInsert(keys) → hash(nodeKey) → moveTo(nodeKey). + // Net: eliminated 1 moveTo (the first one before adaptForInsert). + adaptForInsert(nodeKey, parentKey, leftSibKey, rightSibKey); + nodeHashing.adaptHashesWithAdd(nodeKey); + // Restore cursor to new node — callers expect this (e.g., notifyPrimitiveIndexChange). + // When hashing runs, rollingAdd already does moveTo(startNodeKey) at end, so this is + // only needed when hashing is NONE (bulkInsert && !autoCommit). + nodeReadOnlyTrx.moveTo(nodeKey); } @Override public JsonNodeTrx insertStringValueAsLeftSibling(final String value) { requireNonNull(value); - final byte[] textValue = getBytes(value); - return insertPrimitiveAsSibling((parentKey, leftSib, rightSib, id) -> nodeFactory.createJsonStringNode(parentKey, - leftSib, rightSib, textValue, useTextCompression, id), true); + return insertPrimitiveAsSibling(PrimitiveNodeType.STRING, getBytes(value), null, false, true); } @Override public JsonNodeTrx insertStringValueAsRightSibling(final String value) { requireNonNull(value); - final byte[] textValue = getBytes(value); - return insertPrimitiveAsSibling((parentKey, leftSib, rightSib, id) -> nodeFactory.createJsonStringNode(parentKey, - leftSib, rightSib, textValue, useTextCompression, id), false); + return insertPrimitiveAsSibling(PrimitiveNodeType.STRING, getBytes(value), null, false, false); } @Override public JsonNodeTrx insertBooleanValueAsFirstChild(boolean value) { - return insertPrimitiveAsChild((parentKey, id) -> nodeFactory.createJsonObjectBooleanNode(parentKey, value, id), - (parentKey, leftSib, rightSib, id) -> nodeFactory.createJsonBooleanNode(parentKey, leftSib, rightSib, value, - id), - true, true); + return insertPrimitiveAsChild(PrimitiveNodeType.BOOLEAN, null, null, value, true, true); } @Override public JsonNodeTrx insertBooleanValueAsLastChild(boolean value) { - return insertPrimitiveAsChild((parentKey, id) -> nodeFactory.createJsonObjectBooleanNode(parentKey, value, id), - (parentKey, leftSib, rightSib, id) -> nodeFactory.createJsonBooleanNode(parentKey, leftSib, rightSib, value, - id), - true, false); + return insertPrimitiveAsChild(PrimitiveNodeType.BOOLEAN, null, null, value, true, false); } @Override public JsonNodeTrx insertBooleanValueAsLeftSibling(boolean value) { - return insertPrimitiveAsSibling((parentKey, leftSib, rightSib, id) -> nodeFactory.createJsonBooleanNode(parentKey, - leftSib, rightSib, value, id), true); + return insertPrimitiveAsSibling(PrimitiveNodeType.BOOLEAN, null, null, value, true); } @Override public JsonNodeTrx insertBooleanValueAsRightSibling(boolean value) { - return insertPrimitiveAsSibling((parentKey, leftSib, rightSib, id) -> nodeFactory.createJsonBooleanNode(parentKey, - leftSib, rightSib, value, id), false); + return insertPrimitiveAsSibling(PrimitiveNodeType.BOOLEAN, null, null, value, false); } private void checkPrecondition() { @@ -1351,40 +1385,66 @@ private void checkPrecondition() { } } - private void insertAsSibling(final ImmutableJsonNode node) { - // Adapt local nodes and hashes. - nodeReadOnlyTrx.setCurrentNode(node); - adaptForInsert((StructNode) node); - nodeReadOnlyTrx.setCurrentNode(node); - nodeHashing.adaptHashesWithAdd(); - - // Get the path node key. - final long pathNodeKey; + private void insertAsSibling(final long nodeKey, final long parentKey, + final long leftSibKey, final long rightSibKey, final ImmutableNode insertedNode) { + // Pass structural keys directly — eliminates moveTo before adaptForInsert. + adaptForInsert(nodeKey, parentKey, leftSibKey, rightSibKey); + nodeHashing.adaptHashesWithAdd(nodeKey); + // Restore cursor to new node (rollingAdd does this when hashing, but not when NONE). + nodeReadOnlyTrx.moveTo(nodeKey); - if (buildPathSummary) { - moveToParentObjectKeyArrayOrDocumentRoot(); - pathNodeKey = getPathNodeKey(nodeReadOnlyTrx.getStructuralNode()); - } else { - pathNodeKey = 0; + if (indexController.hasAnyPrimitiveIndex()) { + // Resolve path node key and notify indexes — only when indexes exist. + final long pathNodeKey; + if (buildPathSummary) { + moveToParentObjectKeyArrayOrDocumentRoot(); + pathNodeKey = getPathNodeKey(nodeReadOnlyTrx.getStructuralNodeView()); + nodeReadOnlyTrx.moveTo(nodeKey); + } else { + pathNodeKey = 0; + } + notifyPrimitiveIndexChange(IndexController.ChangeType.INSERT, + (ImmutableNode) nodeReadOnlyTrx.getStructuralNodeView(), pathNodeKey); } - - nodeReadOnlyTrx.setCurrentNode(node); - - notifyPrimitiveIndexChange(IndexController.ChangeType.INSERT, node, pathNodeKey); } - @FunctionalInterface - private interface ObjectKeyNodeCreator { - StructNode create(long parentKey, SirixDeweyID id); + /** + * Enumeration of primitive node types to avoid lambda allocation on the insert hot path. + */ + private enum PrimitiveNodeType { + STRING, NUMBER, BOOLEAN, NULL } - @FunctionalInterface - private interface SiblingNodeCreator { - StructNode create(long parentKey, long leftSibKey, long rightSibKey, SirixDeweyID id); + /** + * Create an object-key child node (direct child of ObjectKeyNode) based on primitive type. + */ + private StructNode createObjectKeyNode(final PrimitiveNodeType type, final long parentKey, + final byte[] stringValue, final Number numberValue, final boolean booleanValue, final SirixDeweyID id) { + return switch (type) { + case STRING -> nodeFactory.createJsonObjectStringNode(parentKey, stringValue, useTextCompression, id); + case NUMBER -> nodeFactory.createJsonObjectNumberNode(parentKey, numberValue, id); + case BOOLEAN -> nodeFactory.createJsonObjectBooleanNode(parentKey, booleanValue, id); + case NULL -> nodeFactory.createJsonObjectNullNode(parentKey, id); + }; } - private JsonNodeTrx insertPrimitiveAsChild(final ObjectKeyNodeCreator objectKeyCreator, - final SiblingNodeCreator arrayCreator, final boolean notifyIndex, final boolean isFirstChild) { + /** + * Create a sibling node (child of array) based on primitive type. + */ + private StructNode createSiblingNode(final PrimitiveNodeType type, final long parentKey, + final long leftSibKey, final long rightSibKey, final byte[] stringValue, final Number numberValue, + final boolean booleanValue, final SirixDeweyID id) { + return switch (type) { + case STRING -> nodeFactory.createJsonStringNode(parentKey, leftSibKey, rightSibKey, + stringValue, useTextCompression, id); + case NUMBER -> nodeFactory.createJsonNumberNode(parentKey, leftSibKey, rightSibKey, numberValue, id); + case BOOLEAN -> nodeFactory.createJsonBooleanNode(parentKey, leftSibKey, rightSibKey, booleanValue, id); + case NULL -> nodeFactory.createJsonNullNode(parentKey, leftSibKey, rightSibKey, id); + }; + } + + private JsonNodeTrx insertPrimitiveAsChild(final PrimitiveNodeType type, final byte[] stringValue, + final Number numberValue, final boolean booleanValue, final boolean notifyIndex, final boolean isFirstChild) { if (lock != null) { lock.lock(); } @@ -1399,43 +1459,52 @@ private JsonNodeTrx insertPrimitiveAsChild(final ObjectKeyNodeCreator objectKeyC checkAccessAndCommit(); } - final StructNode structNode = nodeReadOnlyTrx.getStructuralNode(); - final long pathNodeKey = notifyIndex + final StructNode structNode = nodeReadOnlyTrx.getStructuralNodeView(); + final long pathNodeKey = (notifyIndex && indexController.hasAnyPrimitiveIndex()) ? getPathNodeKey(structNode) : 0; final long parentKey = structNode.getNodeKey(); + final long firstChildKey = structNode.getFirstChildKey(); + final long lastChildKey = structNode.getLastChildKey(); final SirixDeweyID id; final StructNode node; + final long leftSibKey; + final long rightSibKey; if (kind == NodeKind.OBJECT_KEY) { id = deweyIDManager.newRecordValueID(); - node = objectKeyCreator.create(parentKey, id); + leftSibKey = Fixed.NULL_NODE_KEY.getStandardProperty(); + rightSibKey = Fixed.NULL_NODE_KEY.getStandardProperty(); + node = createObjectKeyNode(type, parentKey, stringValue, numberValue, booleanValue, id); } else if (isFirstChild) { id = deweyIDManager.newFirstChildID(); - final long rightSibKey = structNode.getFirstChildKey(); - final long leftSibKey = Fixed.NULL_NODE_KEY.getStandardProperty(); - node = arrayCreator.create(parentKey, leftSibKey, rightSibKey, id); + leftSibKey = Fixed.NULL_NODE_KEY.getStandardProperty(); + rightSibKey = firstChildKey; + node = createSiblingNode(type, parentKey, leftSibKey, rightSibKey, stringValue, numberValue, booleanValue, id); } else { - id = structNode.getFirstChildKey() == Fixed.NULL_NODE_KEY.getStandardProperty() + id = firstChildKey == Fixed.NULL_NODE_KEY.getStandardProperty() ? deweyIDManager.newFirstChildID() : deweyIDManager.newLastChildID(); - final long leftSibKey = structNode.getLastChildKey(); - final long rightSibKey = Fixed.NULL_NODE_KEY.getStandardProperty(); - node = arrayCreator.create(parentKey, leftSibKey, rightSibKey, id); + leftSibKey = lastChildKey; + rightSibKey = Fixed.NULL_NODE_KEY.getStandardProperty(); + node = createSiblingNode(type, parentKey, leftSibKey, rightSibKey, stringValue, numberValue, booleanValue, id); } - adaptNodesAndHashesForInsertAsChild((ImmutableJsonNode) node); + final long nodeKey = node.getNodeKey(); - if (notifyIndex) { - notifyPrimitiveIndexChange(IndexController.ChangeType.INSERT, node, pathNodeKey); + adaptNodesAndHashesForInsertAsChild(nodeKey, parentKey, leftSibKey, rightSibKey); + + if (notifyIndex && indexController.hasAnyPrimitiveIndex()) { + notifyPrimitiveIndexChange(IndexController.ChangeType.INSERT, + (ImmutableNode) nodeReadOnlyTrx.getStructuralNodeView(), pathNodeKey); } if (getParentKind() != NodeKind.OBJECT_KEY && !nodeHashing.isBulkInsert()) { - adaptUpdateOperationsForInsert(id, node.getNodeKey()); + adaptUpdateOperationsForInsert(id, nodeKey); } if (storeNodeHistory) { - nodeToRevisionsIndex.addToRecordToRevisionsIndex(node.getNodeKey()); + nodeToRevisionsIndex.addToRecordToRevisionsIndex(nodeKey); } return this; @@ -1446,7 +1515,8 @@ private JsonNodeTrx insertPrimitiveAsChild(final ObjectKeyNodeCreator objectKeyC } } - private JsonNodeTrx insertPrimitiveAsSibling(final SiblingNodeCreator nodeCreator, final boolean isLeftSibling) { + private JsonNodeTrx insertPrimitiveAsSibling(final PrimitiveNodeType type, final byte[] stringValue, + final Number numberValue, final boolean booleanValue, final boolean isLeftSibling) { if (lock != null) { lock.lock(); } @@ -1455,7 +1525,7 @@ private JsonNodeTrx insertPrimitiveAsSibling(final SiblingNodeCreator nodeCreato checkAccessAndCommit(); checkPrecondition(); - final StructNode currentNode = nodeReadOnlyTrx.getStructuralNode(); + final StructNode currentNode = nodeReadOnlyTrx.getStructuralNodeView(); final long parentKey = currentNode.getParentKey(); final long leftSibKey; @@ -1471,16 +1541,18 @@ private JsonNodeTrx insertPrimitiveAsSibling(final SiblingNodeCreator nodeCreato id = deweyIDManager.newRightSiblingID(); } - final StructNode node = nodeCreator.create(parentKey, leftSibKey, rightSibKey, id); + final StructNode node = createSiblingNode(type, parentKey, leftSibKey, rightSibKey, + stringValue, numberValue, booleanValue, id); + final long nodeKey = node.getNodeKey(); - insertAsSibling((ImmutableJsonNode) node); + insertAsSibling(nodeKey, parentKey, leftSibKey, rightSibKey, (ImmutableNode) node); if (!nodeHashing.isBulkInsert()) { - adaptUpdateOperationsForInsert(id, node.getNodeKey()); + adaptUpdateOperationsForInsert(id, nodeKey); } if (storeNodeHistory) { - nodeToRevisionsIndex.addToRecordToRevisionsIndex(node.getNodeKey()); + nodeToRevisionsIndex.addToRecordToRevisionsIndex(nodeKey); } return this; @@ -1494,25 +1566,19 @@ private JsonNodeTrx insertPrimitiveAsSibling(final SiblingNodeCreator nodeCreato @Override public JsonNodeTrx insertNumberValueAsFirstChild(Number value) { requireNonNull(value); - return insertPrimitiveAsChild((parentKey, id) -> nodeFactory.createJsonObjectNumberNode(parentKey, value, id), - (parentKey, leftSib, rightSib, id) -> nodeFactory.createJsonNumberNode(parentKey, leftSib, rightSib, value, id), - true, true); + return insertPrimitiveAsChild(PrimitiveNodeType.NUMBER, null, value, false, true, true); } @Override public JsonNodeTrx insertNumberValueAsLastChild(Number value) { requireNonNull(value); - return insertPrimitiveAsChild((parentKey, id) -> nodeFactory.createJsonObjectNumberNode(parentKey, value, id), - (parentKey, leftSib, rightSib, id) -> nodeFactory.createJsonNumberNode(parentKey, leftSib, rightSib, value, id), - true, false); + return insertPrimitiveAsChild(PrimitiveNodeType.NUMBER, null, value, false, true, false); } @Override public JsonNodeTrx insertNumberValueAsLeftSibling(Number value) { requireNonNull(value); - return insertPrimitiveAsSibling( - (parentKey, leftSib, rightSib, id) -> nodeFactory.createJsonNumberNode(parentKey, leftSib, rightSib, value, id), - true); + return insertPrimitiveAsSibling(PrimitiveNodeType.NUMBER, null, value, false, true); } @Override @@ -1523,35 +1589,27 @@ public JsonNodeReadOnlyTrx nodeReadOnlyTrxDelegate() { @Override public JsonNodeTrx insertNumberValueAsRightSibling(Number value) { requireNonNull(value); - return insertPrimitiveAsSibling( - (parentKey, leftSib, rightSib, id) -> nodeFactory.createJsonNumberNode(parentKey, leftSib, rightSib, value, id), - false); + return insertPrimitiveAsSibling(PrimitiveNodeType.NUMBER, null, value, false, false); } @Override public JsonNodeTrx insertNullValueAsFirstChild() { - return insertPrimitiveAsChild((parentKey, id) -> nodeFactory.createJsonObjectNullNode(parentKey, id), - (parentKey, leftSib, rightSib, id) -> nodeFactory.createJsonNullNode(parentKey, leftSib, rightSib, id), false, - true); + return insertPrimitiveAsChild(PrimitiveNodeType.NULL, null, null, false, false, true); } @Override public JsonNodeTrx insertNullValueAsLastChild() { - return insertPrimitiveAsChild((parentKey, id) -> nodeFactory.createJsonObjectNullNode(parentKey, id), - (parentKey, leftSib, rightSib, id) -> nodeFactory.createJsonNullNode(parentKey, leftSib, rightSib, id), false, - false); + return insertPrimitiveAsChild(PrimitiveNodeType.NULL, null, null, false, false, false); } @Override public JsonNodeTrx insertNullValueAsLeftSibling() { - return insertPrimitiveAsSibling( - (parentKey, leftSib, rightSib, id) -> nodeFactory.createJsonNullNode(parentKey, leftSib, rightSib, id), true); + return insertPrimitiveAsSibling(PrimitiveNodeType.NULL, null, null, false, true); } @Override public JsonNodeTrx insertNullValueAsRightSibling() { - return insertPrimitiveAsSibling( - (parentKey, leftSib, rightSib, id) -> nodeFactory.createJsonNullNode(parentKey, leftSib, rightSib, id), false); + return insertPrimitiveAsSibling(PrimitiveNodeType.NULL, null, null, false, false); } /** @@ -1676,7 +1734,17 @@ private void notifyPrimitiveIndexChange(final IndexController.ChangeType type, f final QNm name; if (kind == NodeKind.OBJECT_KEY && indexController.hasNameIndex() && node instanceof ObjectKeyNode objectKeyNode) { - name = objectKeyNode.getName(); + // getName() may be null for flyweight-bound nodes (cachedName is a Java field, not in MemorySegment). + // Fall back to resolving the name from the name key via the storage engine. + QNm resolvedName = objectKeyNode.getName(); + if (resolvedName == null) { + final int nameKey = objectKeyNode.getNameKey(); + final String localName = storageEngineWriter.getName(nameKey, NodeKind.OBJECT_KEY); + if (localName != null) { + resolvedName = new QNm(localName); + } + } + name = resolvedName; } else { name = null; } @@ -1990,22 +2058,19 @@ public JsonNodeTrx setNumberValue(final Number value) { // //////////////////////////////////////////////////////////// /** - * Adapting everything for insert operations. + * Adapting everything for insert operations. Accepts the new node's structural keys directly + * to avoid a moveTo call — the caller already knows these values from the factory call. * - * @param structNode pointer of the new node to be inserted + * @param structNodeKey the new node's key + * @param parentKey the new node's parent key + * @param leftSibKey the new node's left sibling key + * @param rightSibKey the new node's right sibling key * @throws SirixIOException if anything weird happens */ - private void adaptForInsert(final StructNode structNode) { - assert structNode != null; - // Capture all needed keys from structNode before any prepareRecordForModification calls. - // With write-path singletons, prepareRecordForModification for a node of the same kind - // would overwrite the singleton, invalidating prior references. - final long structNodeKey = structNode.getNodeKey(); - final long parentKey = structNode.getParentKey(); - final long leftSibKey = structNode.getLeftSiblingKey(); - final long rightSibKey = structNode.getRightSiblingKey(); - final boolean hasLeft = structNode.hasLeftSibling(); - final boolean hasRight = structNode.hasRightSibling(); + private void adaptForInsert(final long structNodeKey, final long parentKey, + final long leftSibKey, final long rightSibKey) { + final boolean hasLeft = leftSibKey != Fixed.NULL_NODE_KEY.getStandardProperty(); + final boolean hasRight = rightSibKey != Fixed.NULL_NODE_KEY.getStandardProperty(); // Phase 1: Update parent — childCount + firstChild/lastChild if no siblings. // Complete all parent modifications and persist BEFORE acquiring any sibling singletons. @@ -2156,7 +2221,14 @@ protected AbstractNodeHashing reInstantiateN @Override protected JsonNodeFactory reInstantiateNodeFactory(StorageEngineWriter storageEngineWriter) { - return new JsonNodeFactoryImpl(hashFunction, storageEngineWriter); + final var factory = new JsonNodeFactoryImpl(hashFunction, storageEngineWriter); + wireWriteSingletonBinder(factory, storageEngineWriter); + return factory; + } + + private static void wireWriteSingletonBinder(final JsonNodeFactoryImpl factory, + final StorageEngineWriter storageEngineWriter) { + storageEngineWriter.setWriteSingletonBinder(factory::bindWriteSingleton); } @Override diff --git a/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/xml/InsertPos.java b/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/xml/InsertPos.java index 989454e82..81b071d70 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/xml/InsertPos.java +++ b/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/xml/InsertPos.java @@ -26,6 +26,7 @@ import io.sirix.index.IndexType; import io.sirix.node.NodeKind; import io.sirix.node.interfaces.DataRecord; +import io.sirix.node.interfaces.FlyweightNode; import io.sirix.node.interfaces.StructNode; import io.sirix.settings.Fixed; import io.brackit.query.atomic.QNm; @@ -359,6 +360,10 @@ abstract void processMove(final StructNode fromNode, final StructNode toNode, fi abstract void insertNode(final XmlNodeTrx wtx, final XmlNodeReadOnlyTrx rtx) throws SirixException; private static void persistUpdatedRecord(final XmlNodeTrx wtx, final DataRecord record) { - wtx.getStorageEngineWriter().updateRecordSlot(record, IndexType.DOCUMENT, -1); + if (record instanceof FlyweightNode fn && fn.isWriteSingleton() && fn.getOwnerPage() != null) { + return; // Bound write singleton — mutations already on heap via inlined setters + } + // Ensure the mutated record is stored in the TIL's modified page. + wtx.getStorageEngineWriter().persistRecord(record, IndexType.DOCUMENT, -1); } } diff --git a/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/xml/XmlDeweyIDManager.java b/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/xml/XmlDeweyIDManager.java index fd9bac62d..0a3303077 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/xml/XmlDeweyIDManager.java +++ b/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/xml/XmlDeweyIDManager.java @@ -7,6 +7,7 @@ import io.sirix.index.IndexType; import io.sirix.node.SirixDeweyID; import io.sirix.node.interfaces.DataRecord; +import io.sirix.node.interfaces.FlyweightNode; import io.sirix.node.interfaces.Node; import io.sirix.node.interfaces.StructNode; import io.sirix.node.xml.ElementNode; @@ -182,7 +183,11 @@ SirixDeweyID newAttributeID() { } private void persistUpdatedRecord(final DataRecord record) { - storageEngineWriter.updateRecordSlot(record, IndexType.DOCUMENT, -1); + if (record instanceof FlyweightNode fn && fn.isWriteSingleton() && fn.getOwnerPage() != null) { + return; // Bound write singleton — mutations already on heap via inlined setters + } + // Ensure the mutated record is stored in the TIL's modified page. + storageEngineWriter.persistRecord(record, IndexType.DOCUMENT, -1); } } diff --git a/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/xml/XmlNodeFactoryImpl.java b/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/xml/XmlNodeFactoryImpl.java index 9cb4c03cf..8334e02a7 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/xml/XmlNodeFactoryImpl.java +++ b/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/xml/XmlNodeFactoryImpl.java @@ -8,12 +8,16 @@ import io.sirix.node.delegates.NameNodeDelegate; import io.sirix.node.delegates.NodeDelegate; import io.sirix.node.delegates.StructNodeDelegate; +import io.sirix.node.interfaces.DataRecord; import io.sirix.node.xml.AttributeNode; import io.sirix.node.xml.CommentNode; import io.sirix.node.xml.ElementNode; import io.sirix.node.xml.NamespaceNode; import io.sirix.node.xml.PINode; import io.sirix.node.xml.TextNode; +import io.sirix.node.xml.XmlDocumentRootNode; +import io.sirix.page.KeyValueLeafPage; +import io.sirix.page.PageLayout; import io.sirix.page.PathSummaryPage; import io.sirix.settings.Constants; import io.sirix.settings.Fixed; @@ -25,6 +29,7 @@ import org.checkerframework.checker.index.qual.NonNegative; import org.checkerframework.checker.nullness.qual.NonNull; +import java.lang.foreign.MemorySegment; import java.util.zip.Deflater; import static java.util.Objects.requireNonNull; @@ -36,6 +41,8 @@ */ final class XmlNodeFactoryImpl implements XmlNodeFactory { + private static final long NULL_KEY = Fixed.NULL_NODE_KEY.getStandardProperty(); + /** * {@link StorageEngineWriter} implementation. */ @@ -62,6 +69,7 @@ final class XmlNodeFactoryImpl implements XmlNodeFactory { private final LongArrayList reusableElementAttributeKeys; private final LongArrayList reusableElementNamespaceKeys; private final ElementNode reusableElementNode; + private final XmlDocumentRootNode reusableXmlDocumentRootNode; /** * Constructor. @@ -97,129 +105,16 @@ final class XmlNodeFactoryImpl implements XmlNodeFactory { this.reusableCommentNode = new CommentNode(0, 0, Constants.NULL_REVISION_NUMBER, revisionNumber, Fixed.NULL_NODE_KEY.getStandardProperty(), Fixed.NULL_NODE_KEY.getStandardProperty(), 0, new byte[0], false, hashFunction, (SirixDeweyID) null); - } - - private long nextNodeKey() { - return storageEngineWriter.getActualRevisionRootPage().getMaxNodeKeyInDocumentIndex() + 1; - } - - private AttributeNode bindAttributeNode(final long nodeKey, final long parentKey, final QNm name, final byte[] value, - final long pathNodeKey, final int prefixKey, final int localNameKey, final int uriKey, final SirixDeweyID id) { - final AttributeNode node = reusableAttributeNode; - node.setNodeKey(nodeKey); - node.setParentKey(parentKey); - node.setPathNodeKey(pathNodeKey); - node.setPrefixKey(prefixKey); - node.setLocalNameKey(localNameKey); - node.setURIKey(uriKey); - node.setPreviousRevision(Constants.NULL_REVISION_NUMBER); - node.setLastModifiedRevision(revisionNumber); - node.setRawValue(value); - node.setHash(0); - node.setName(name); - node.setDeweyID(id); - return node; - } - - private NamespaceNode bindNamespaceNode(final long nodeKey, final long parentKey, final QNm name, - final long pathNodeKey, final int prefixKey, final int uriKey, final SirixDeweyID id) { - final NamespaceNode node = reusableNamespaceNode; - node.setNodeKey(nodeKey); - node.setParentKey(parentKey); - node.setPathNodeKey(pathNodeKey); - node.setPrefixKey(prefixKey); - node.setLocalNameKey(-1); - node.setURIKey(uriKey); - node.setPreviousRevision(Constants.NULL_REVISION_NUMBER); - node.setLastModifiedRevision(revisionNumber); - node.setHash(0); - node.setName(name); - node.setDeweyID(id); - return node; - } - - private PINode bindPINode(final long nodeKey, final long parentKey, final long leftSibKey, final long rightSibKey, - final QNm target, final byte[] content, final long pathNodeKey, final int prefixKey, final int localNameKey, - final int uriKey, final boolean isCompressed, final SirixDeweyID id) { - final PINode node = reusablePINode; - node.setNodeKey(nodeKey); - node.setParentKey(parentKey); - node.setRightSiblingKey(rightSibKey); - node.setLeftSiblingKey(leftSibKey); - node.setFirstChildKey(Fixed.NULL_NODE_KEY.getStandardProperty()); - node.setLastChildKey(Fixed.NULL_NODE_KEY.getStandardProperty()); - node.setChildCount(0); - node.setDescendantCount(0); - node.setPathNodeKey(pathNodeKey); - node.setPrefixKey(prefixKey); - node.setLocalNameKey(localNameKey); - node.setURIKey(uriKey); - node.setPreviousRevision(Constants.NULL_REVISION_NUMBER); - node.setLastModifiedRevision(revisionNumber); - node.setRawValue(content); - node.setCompressed(isCompressed); - node.setHash(0); - node.setName(target); - node.setDeweyID(id); - return node; - } - - private ElementNode bindElementNode(final long nodeKey, final long parentKey, final long leftSibKey, - final long rightSibKey, final QNm name, final long pathNodeKey, final int prefixKey, final int localNameKey, - final int uriKey, final SirixDeweyID id) { - reusableElementAttributeKeys.clear(); - reusableElementNamespaceKeys.clear(); - final ElementNode node = reusableElementNode; - node.setNodeKey(nodeKey); - node.setParentKey(parentKey); - node.setRightSiblingKey(rightSibKey); - node.setLeftSiblingKey(leftSibKey); - node.setFirstChildKey(Fixed.NULL_NODE_KEY.getStandardProperty()); - node.setLastChildKey(Fixed.NULL_NODE_KEY.getStandardProperty()); - node.setChildCount(0); - node.setDescendantCount(0); - node.setPathNodeKey(pathNodeKey); - node.setPrefixKey(prefixKey); - node.setLocalNameKey(localNameKey); - node.setURIKey(uriKey); - node.setPreviousRevision(Constants.NULL_REVISION_NUMBER); - node.setLastModifiedRevision(revisionNumber); - node.setHash(0); - node.setName(name); - node.setDeweyID(id); - return node; - } - - private TextNode bindTextNode(final long nodeKey, final long parentKey, final long leftSibKey, final long rightSibKey, - final byte[] value, final boolean isCompressed, final SirixDeweyID id) { - final TextNode node = reusableTextNode; - node.setNodeKey(nodeKey); - node.setParentKey(parentKey); - node.setPreviousRevision(Constants.NULL_REVISION_NUMBER); - node.setLastModifiedRevision(revisionNumber); - node.setRightSiblingKey(rightSibKey); - node.setLeftSiblingKey(leftSibKey); - node.setRawValue(value); - node.setCompressed(isCompressed); - node.setHash(0); - node.setDeweyID(id); - return node; - } + this.reusableXmlDocumentRootNode = new XmlDocumentRootNode(0, hashFunction); - private CommentNode bindCommentNode(final long nodeKey, final long parentKey, final long leftSibKey, - final long rightSibKey, final byte[] value, final boolean isCompressed, final SirixDeweyID id) { - final CommentNode node = reusableCommentNode; - node.setNodeKey(nodeKey); - node.setParentKey(parentKey); - node.setPreviousRevision(Constants.NULL_REVISION_NUMBER); - node.setLastModifiedRevision(revisionNumber); - node.setRightSiblingKey(rightSibKey); - node.setLeftSiblingKey(leftSibKey); - node.setRawValue(value); - node.setCompressed(isCompressed); - node.setHash(0); - node.setDeweyID(id); - return node; + // Mark all singletons as write singletons so setRecord skips records[] storage. + reusableElementNode.setWriteSingleton(true); + reusableAttributeNode.setWriteSingleton(true); + reusableNamespaceNode.setWriteSingleton(true); + reusablePINode.setWriteSingleton(true); + reusableTextNode.setWriteSingleton(true); + reusableCommentNode.setWriteSingleton(true); + reusableXmlDocumentRootNode.setWriteSingleton(true); } @Override @@ -258,25 +153,53 @@ public ElementNode createElementNode(final @NonNegative long parentKey, final @N ? storageEngineWriter.createNameKey(name.getPrefix(), NodeKind.ELEMENT) : -1; final int localNameKey = storageEngineWriter.createNameKey(name.getLocalName(), NodeKind.ELEMENT); - final long nodeKey = nextNodeKey(); - final ElementNode node = bindElementNode(nodeKey, parentKey, leftSibKey, rightSibKey, name, pathNodeKey, prefixKey, - localNameKey, uriKey, id); - return storageEngineWriter.createRecord(node, IndexType.DOCUMENT, -1); + storageEngineWriter.allocateForDocumentCreation(); + final KeyValueLeafPage kvl = storageEngineWriter.getAllocKvl(); + final long nodeKey = storageEngineWriter.getAllocNodeKey(); + final int slotOffset = storageEngineWriter.getAllocSlotOffset(); + final byte[] deweyIdBytes = (id != null && kvl.areDeweyIDsStored()) ? id.toBytes() : null; + final int deweyIdLen = deweyIdBytes != null ? deweyIdBytes.length : 0; + final long absOffset = kvl.prepareHeapForDirectWrite( + reusableElementNode.estimateSerializedSize(), deweyIdLen); + reusableElementAttributeKeys.clear(); + reusableElementNamespaceKeys.clear(); + final int recordBytes = ElementNode.writeNewRecord(kvl.getSlottedPage(), absOffset, + reusableElementNode.getHeapOffsets(), nodeKey, parentKey, rightSibKey, leftSibKey, + NULL_KEY, NULL_KEY, pathNodeKey, prefixKey, localNameKey, uriKey, + Constants.NULL_REVISION_NUMBER, revisionNumber, 0, 0, 0); + kvl.completeDirectWrite(NodeKind.ELEMENT.getId(), nodeKey, slotOffset, recordBytes, deweyIdBytes); + reusableElementNode.bind(kvl.getSlottedPage(), absOffset, nodeKey, slotOffset); + reusableElementNode.setOwnerPage(kvl); + reusableElementNode.setDeweyIDAfterCreation(id, deweyIdBytes); + reusableElementNode.setName(name); + return reusableElementNode; } @Override public TextNode createTextNode(final @NonNegative long parentKey, final @NonNegative long leftSibKey, final @NonNegative long rightSibKey, final byte[] value, final boolean isCompressed, final SirixDeweyID id) { - final long nodeKey = nextNodeKey(); - // Compress value if needed final boolean compression = isCompressed && value.length > 10; final byte[] compressedValue = compression ? Compression.compress(value, Deflater.HUFFMAN_ONLY) : value; - final TextNode node = bindTextNode(nodeKey, parentKey, leftSibKey, rightSibKey, compressedValue, compression, id); - return storageEngineWriter.createRecord(node, IndexType.DOCUMENT, -1); + storageEngineWriter.allocateForDocumentCreation(); + final KeyValueLeafPage kvl = storageEngineWriter.getAllocKvl(); + final long nodeKey = storageEngineWriter.getAllocNodeKey(); + final int slotOffset = storageEngineWriter.getAllocSlotOffset(); + final byte[] deweyIdBytes = (id != null && kvl.areDeweyIDsStored()) ? id.toBytes() : null; + final int deweyIdLen = deweyIdBytes != null ? deweyIdBytes.length : 0; + final long absOffset = kvl.prepareHeapForDirectWrite( + 55 + compressedValue.length, deweyIdLen); + final int recordBytes = TextNode.writeNewRecord(kvl.getSlottedPage(), absOffset, + reusableTextNode.getHeapOffsets(), nodeKey, parentKey, rightSibKey, leftSibKey, + Constants.NULL_REVISION_NUMBER, revisionNumber, compressedValue, compression); + kvl.completeDirectWrite(NodeKind.TEXT.getId(), nodeKey, slotOffset, recordBytes, deweyIdBytes); + reusableTextNode.bind(kvl.getSlottedPage(), absOffset, nodeKey, slotOffset); + reusableTextNode.setOwnerPage(kvl); + reusableTextNode.setDeweyIDAfterCreation(id, deweyIdBytes); + return reusableTextNode; } @Override @@ -287,10 +210,24 @@ public AttributeNode createAttributeNode(final @NonNegative long parentKey, fina ? storageEngineWriter.createNameKey(name.getPrefix(), NodeKind.ATTRIBUTE) : -1; final int localNameKey = storageEngineWriter.createNameKey(name.getLocalName(), NodeKind.ATTRIBUTE); - final long nodeKey = nextNodeKey(); - final AttributeNode node = - bindAttributeNode(nodeKey, parentKey, name, value, pathNodeKey, prefixKey, localNameKey, uriKey, id); - return storageEngineWriter.createRecord(node, IndexType.DOCUMENT, -1); + storageEngineWriter.allocateForDocumentCreation(); + final KeyValueLeafPage kvl = storageEngineWriter.getAllocKvl(); + final long nodeKey = storageEngineWriter.getAllocNodeKey(); + final int slotOffset = storageEngineWriter.getAllocSlotOffset(); + final byte[] deweyIdBytes = (id != null && kvl.areDeweyIDsStored()) ? id.toBytes() : null; + final int deweyIdLen = deweyIdBytes != null ? deweyIdBytes.length : 0; + final long absOffset = kvl.prepareHeapForDirectWrite( + 64 + value.length, deweyIdLen); + final int recordBytes = AttributeNode.writeNewRecord(kvl.getSlottedPage(), absOffset, + reusableAttributeNode.getHeapOffsets(), nodeKey, parentKey, pathNodeKey, + prefixKey, localNameKey, uriKey, + Constants.NULL_REVISION_NUMBER, revisionNumber, value); + kvl.completeDirectWrite(NodeKind.ATTRIBUTE.getId(), nodeKey, slotOffset, recordBytes, deweyIdBytes); + reusableAttributeNode.bind(kvl.getSlottedPage(), absOffset, nodeKey, slotOffset); + reusableAttributeNode.setOwnerPage(kvl); + reusableAttributeNode.setDeweyIDAfterCreation(id, deweyIdBytes); + reusableAttributeNode.setName(name); + return reusableAttributeNode; } @Override @@ -301,9 +238,24 @@ public NamespaceNode createNamespaceNode(final @NonNegative long parentKey, fina ? storageEngineWriter.createNameKey(name.getPrefix(), NodeKind.NAMESPACE) : -1; - final long nodeKey = nextNodeKey(); - final NamespaceNode node = bindNamespaceNode(nodeKey, parentKey, name, pathNodeKey, prefixKey, uriKey, id); - return storageEngineWriter.createRecord(node, IndexType.DOCUMENT, -1); + storageEngineWriter.allocateForDocumentCreation(); + final KeyValueLeafPage kvl = storageEngineWriter.getAllocKvl(); + final long nodeKey = storageEngineWriter.getAllocNodeKey(); + final int slotOffset = storageEngineWriter.getAllocSlotOffset(); + final byte[] deweyIdBytes = (id != null && kvl.areDeweyIDsStored()) ? id.toBytes() : null; + final int deweyIdLen = deweyIdBytes != null ? deweyIdBytes.length : 0; + final long absOffset = kvl.prepareHeapForDirectWrite( + reusableNamespaceNode.estimateSerializedSize(), deweyIdLen); + final int recordBytes = NamespaceNode.writeNewRecord(kvl.getSlottedPage(), absOffset, + reusableNamespaceNode.getHeapOffsets(), nodeKey, parentKey, pathNodeKey, + prefixKey, -1, uriKey, + Constants.NULL_REVISION_NUMBER, revisionNumber, 0); + kvl.completeDirectWrite(NodeKind.NAMESPACE.getId(), nodeKey, slotOffset, recordBytes, deweyIdBytes); + reusableNamespaceNode.bind(kvl.getSlottedPage(), absOffset, nodeKey, slotOffset); + reusableNamespaceNode.setOwnerPage(kvl); + reusableNamespaceNode.setDeweyIDAfterCreation(id, deweyIdBytes); + reusableNamespaceNode.setName(name); + return reusableNamespaceNode; } @Override @@ -315,29 +267,126 @@ public PINode createPINode(final @NonNegative long parentKey, final @NonNegative : -1; final int localNameKey = storageEngineWriter.createNameKey(target.getLocalName(), NodeKind.PROCESSING_INSTRUCTION); final int uriKey = storageEngineWriter.createNameKey(target.getNamespaceURI(), NodeKind.NAMESPACE); - final long nodeKey = nextNodeKey(); final boolean compression = isCompressed && content.length > 10; final byte[] compressedContent = compression ? Compression.compress(content, Deflater.HUFFMAN_ONLY) : content; - final PINode node = bindPINode(nodeKey, parentKey, leftSibKey, rightSibKey, target, compressedContent, pathNodeKey, - prefixKey, localNameKey, uriKey, compression, id); - return storageEngineWriter.createRecord(node, IndexType.DOCUMENT, -1); + storageEngineWriter.allocateForDocumentCreation(); + final KeyValueLeafPage kvl = storageEngineWriter.getAllocKvl(); + final long nodeKey = storageEngineWriter.getAllocNodeKey(); + final int slotOffset = storageEngineWriter.getAllocSlotOffset(); + final byte[] deweyIdBytes = (id != null && kvl.areDeweyIDsStored()) ? id.toBytes() : null; + final int deweyIdLen = deweyIdBytes != null ? deweyIdBytes.length : 0; + final long absOffset = kvl.prepareHeapForDirectWrite( + 64 + compressedContent.length, deweyIdLen); + final int recordBytes = PINode.writeNewRecord(kvl.getSlottedPage(), absOffset, + reusablePINode.getHeapOffsets(), nodeKey, parentKey, rightSibKey, leftSibKey, + NULL_KEY, NULL_KEY, pathNodeKey, prefixKey, localNameKey, uriKey, + Constants.NULL_REVISION_NUMBER, revisionNumber, 0, 0, + compressedContent, compression); + kvl.completeDirectWrite(NodeKind.PROCESSING_INSTRUCTION.getId(), nodeKey, slotOffset, recordBytes, deweyIdBytes); + reusablePINode.bind(kvl.getSlottedPage(), absOffset, nodeKey, slotOffset); + reusablePINode.setOwnerPage(kvl); + reusablePINode.setDeweyIDAfterCreation(id, deweyIdBytes); + reusablePINode.setName(target); + return reusablePINode; } @Override public CommentNode createCommentNode(final @NonNegative long parentKey, final @NonNegative long leftSibKey, final @NonNegative long rightSibKey, final byte[] value, final boolean isCompressed, final SirixDeweyID id) { - final long nodeKey = nextNodeKey(); - // Compress value if needed final boolean compression = isCompressed && value.length > 10; final byte[] compressedValue = compression ? Compression.compress(value, Deflater.HUFFMAN_ONLY) : value; - final CommentNode node = - bindCommentNode(nodeKey, parentKey, leftSibKey, rightSibKey, compressedValue, compression, id); - return storageEngineWriter.createRecord(node, IndexType.DOCUMENT, -1); + storageEngineWriter.allocateForDocumentCreation(); + final KeyValueLeafPage kvl = storageEngineWriter.getAllocKvl(); + final long nodeKey = storageEngineWriter.getAllocNodeKey(); + final int slotOffset = storageEngineWriter.getAllocSlotOffset(); + final byte[] deweyIdBytes = (id != null && kvl.areDeweyIDsStored()) ? id.toBytes() : null; + final int deweyIdLen = deweyIdBytes != null ? deweyIdBytes.length : 0; + final long absOffset = kvl.prepareHeapForDirectWrite( + 55 + compressedValue.length, deweyIdLen); + final int recordBytes = CommentNode.writeNewRecord(kvl.getSlottedPage(), absOffset, + reusableCommentNode.getHeapOffsets(), nodeKey, parentKey, rightSibKey, leftSibKey, + Constants.NULL_REVISION_NUMBER, revisionNumber, compressedValue, compression); + kvl.completeDirectWrite(NodeKind.COMMENT.getId(), nodeKey, slotOffset, recordBytes, deweyIdBytes); + reusableCommentNode.bind(kvl.getSlottedPage(), absOffset, nodeKey, slotOffset); + reusableCommentNode.setOwnerPage(kvl); + reusableCommentNode.setDeweyIDAfterCreation(id, deweyIdBytes); + return reusableCommentNode; + } + + /** + * Bind the correct write singleton to a slotted page slot for zero-allocation modification. + * Reads the nodeKindId from the page directory, selects the matching singleton, binds to the + * slot, and propagates DeweyID. + * + * @param page the KeyValueLeafPage containing the slotted page + * @param offset the slot index (0-1023) + * @param nodeKey the record key + * @return the bound write singleton, or null if the slot is not an XML node type + */ + DataRecord bindWriteSingleton(final KeyValueLeafPage page, final int offset, final long nodeKey) { + final MemorySegment slottedPage = page.getSlottedPage(); + if (slottedPage == null || !PageLayout.isSlotPopulated(slottedPage, offset)) { + return null; + } + final int nodeKindId = PageLayout.getDirNodeKindId(slottedPage, offset); + final int heapOffset = PageLayout.getDirHeapOffset(slottedPage, offset); + final long recordBase = PageLayout.heapAbsoluteOffset(heapOffset); + final byte[] deweyIdBytes = page.getDeweyIdAsByteArray(offset); + + // Concrete-type switch eliminates 3 itable stubs per bind (bind, setDeweyIDBytes, setOwnerPage). + // Each case is monomorphic — JVM can inline directly. + // setDeweyIDBytes stores raw bytes lazily (no SirixDeweyID parsing). + // No setOwnerPage(null) needed — setDeweyIDBytes doesn't trigger resize. + return switch (nodeKindId) { + case 1 -> { // ELEMENT + reusableElementNode.bind(slottedPage, recordBase, nodeKey, offset); + reusableElementNode.setDeweyIDBytes(deweyIdBytes); + reusableElementNode.setOwnerPage(page); + yield reusableElementNode; + } + case 2 -> { // ATTRIBUTE + reusableAttributeNode.bind(slottedPage, recordBase, nodeKey, offset); + reusableAttributeNode.setDeweyIDBytes(deweyIdBytes); + reusableAttributeNode.setOwnerPage(page); + yield reusableAttributeNode; + } + case 3 -> { // TEXT + reusableTextNode.bind(slottedPage, recordBase, nodeKey, offset); + reusableTextNode.setDeweyIDBytes(deweyIdBytes); + reusableTextNode.setOwnerPage(page); + yield reusableTextNode; + } + case 7 -> { // PROCESSING_INSTRUCTION + reusablePINode.bind(slottedPage, recordBase, nodeKey, offset); + reusablePINode.setDeweyIDBytes(deweyIdBytes); + reusablePINode.setOwnerPage(page); + yield reusablePINode; + } + case 8 -> { // COMMENT + reusableCommentNode.bind(slottedPage, recordBase, nodeKey, offset); + reusableCommentNode.setDeweyIDBytes(deweyIdBytes); + reusableCommentNode.setOwnerPage(page); + yield reusableCommentNode; + } + case 9 -> { // XML_DOCUMENT + reusableXmlDocumentRootNode.bind(slottedPage, recordBase, nodeKey, offset); + reusableXmlDocumentRootNode.setDeweyIDBytes(deweyIdBytes); + reusableXmlDocumentRootNode.setOwnerPage(page); + yield reusableXmlDocumentRootNode; + } + case 13 -> { // NAMESPACE + reusableNamespaceNode.bind(slottedPage, recordBase, nodeKey, offset); + reusableNamespaceNode.setDeweyIDBytes(deweyIdBytes); + reusableNamespaceNode.setOwnerPage(page); + yield reusableNamespaceNode; + } + default -> null; + }; } } diff --git a/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/xml/XmlNodeTrxImpl.java b/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/xml/XmlNodeTrxImpl.java index 5ed7d46f1..022461bdd 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/xml/XmlNodeTrxImpl.java +++ b/bundles/sirix-core/src/main/java/io/sirix/access/trx/node/xml/XmlNodeTrxImpl.java @@ -146,6 +146,11 @@ final class XmlNodeTrxImpl extends useTextCompression = resourceSession.getResourceConfig().useTextCompression; deweyIDManager = new XmlDeweyIDManager(this); + // Wire write singleton binder for zero-allocation write path. + if (nodeFactory instanceof XmlNodeFactoryImpl factoryImpl) { + wireWriteSingletonBinder(factoryImpl, storageEngineWriter); + } + // Register index listeners for any existing indexes. // This is critical for subsequent write transactions to update indexes on node modifications. final var existingIndexDefs = indexController.getIndexes().getIndexDefs(); @@ -543,13 +548,13 @@ public XmlNodeTrx insertElementAsFirstChild(final QNm name) { : 0; final SirixDeweyID id = deweyIDManager.newFirstChildID(); final ElementNode node = nodeFactory.createElementNode(parentKey, leftSibKey, rightSibKey, name, pathNodeKey, id); + final long nodeKey = node.getNodeKey(); - nodeReadOnlyTrx.setCurrentNode(node); adaptForInsert(node, InsertPos.ASFIRSTCHILD); - nodeReadOnlyTrx.setCurrentNode(node); - nodeHashing.adaptHashesWithAdd(); + nodeHashing.adaptHashesWithAdd(nodeKey); + moveTo(nodeKey); - notifyPrimitiveIndexChange(IndexController.ChangeType.INSERT, node, pathNodeKey); + notifyPrimitiveIndexChange(IndexController.ChangeType.INSERT, nodeReadOnlyTrx.getCurrentNode(), pathNodeKey); return this; } finally { @@ -590,13 +595,13 @@ public XmlNodeTrx insertElementAsLeftSibling(final QNm name) { final SirixDeweyID id = deweyIDManager.newLeftSiblingID(); final ElementNode node = nodeFactory.createElementNode(parentKey, leftSibKey, rightSibKey, name, pathNodeKey, id); + final long nodeKey = node.getNodeKey(); - nodeReadOnlyTrx.setCurrentNode(node); adaptForInsert(node, InsertPos.ASLEFTSIBLING); - nodeReadOnlyTrx.setCurrentNode(node); - nodeHashing.adaptHashesWithAdd(); + nodeHashing.adaptHashesWithAdd(nodeKey); + moveTo(nodeKey); - notifyPrimitiveIndexChange(IndexController.ChangeType.INSERT, node, pathNodeKey); + notifyPrimitiveIndexChange(IndexController.ChangeType.INSERT, nodeReadOnlyTrx.getCurrentNode(), pathNodeKey); return this; } finally { @@ -629,7 +634,15 @@ public XmlNodeTrx insertElementAsRightSibling(final QNm name) { final long parentKey = currentNode.getParentKey(); final long leftSibKey = currentNode.getNodeKey(); final long rightSibKey = currentNode.getRightSiblingKey(); - moveToParent(); + final boolean moveResult = moveToParent(); + if (!moveResult) { + throw new IllegalStateException("moveToParent() failed from nodeKey=" + key + + " kind=" + currentKind + " parentKey=" + parentKey); + } + if (getKind() != NodeKind.ELEMENT && getKind() != NodeKind.XML_DOCUMENT) { + throw new IllegalStateException("After moveToParent(), expected ELEMENT or XML_DOCUMENT but got kind=" + + getKind() + " nodeKey=" + getNodeKey() + " from child nodeKey=" + key + " kind=" + currentKind); + } final long pathNodeKey = buildPathSummary ? pathSummaryWriter.getPathNodeKey(name, NodeKind.ELEMENT) : 0; @@ -637,13 +650,13 @@ public XmlNodeTrx insertElementAsRightSibling(final QNm name) { final SirixDeweyID id = deweyIDManager.newRightSiblingID(); final ElementNode node = nodeFactory.createElementNode(parentKey, leftSibKey, rightSibKey, name, pathNodeKey, id); + final long nodeKey = node.getNodeKey(); - nodeReadOnlyTrx.setCurrentNode(node); adaptForInsert(node, InsertPos.ASRIGHTSIBLING); - nodeReadOnlyTrx.setCurrentNode(node); - nodeHashing.adaptHashesWithAdd(); + nodeHashing.adaptHashesWithAdd(nodeKey); + moveTo(nodeKey); - notifyPrimitiveIndexChange(IndexController.ChangeType.INSERT, node, pathNodeKey); + notifyPrimitiveIndexChange(IndexController.ChangeType.INSERT, nodeReadOnlyTrx.getCurrentNode(), pathNodeKey); return this; } finally { @@ -818,12 +831,12 @@ private XmlNodeTrx pi(final String target, final String content, final InsertPos : 0; final PINode node = nodeFactory.createPINode(pk.parentKey(), pk.leftSibKey(), pk.rightSibKey(), targetName, processingContent, useTextCompression, pathNodeKey, pk.id()); + final long nodeKey = node.getNodeKey(); // Adapt local nodes and hashes. - nodeReadOnlyTrx.setCurrentNode(node); adaptForInsert(node, pk.pos()); - nodeReadOnlyTrx.setCurrentNode(node); - nodeHashing.adaptHashesWithAdd(); + nodeHashing.adaptHashesWithAdd(nodeKey); + moveTo(nodeKey); return this; } finally { @@ -881,12 +894,12 @@ private XmlNodeTrx comment(final String value, final InsertPosition insert) { final byte[] commentValue = getBytes(value); final CommentNode node = nodeFactory.createCommentNode(pk.parentKey(), pk.leftSibKey(), pk.rightSibKey(), commentValue, useTextCompression, pk.id()); + final long nodeKey = node.getNodeKey(); // Adapt local nodes and hashes. - nodeReadOnlyTrx.setCurrentNode(node); adaptForInsert(node, pk.pos()); - nodeReadOnlyTrx.setCurrentNode(node); - nodeHashing.adaptHashesWithAdd(); + nodeHashing.adaptHashesWithAdd(nodeKey); + moveTo(nodeKey); return this; } finally { @@ -933,15 +946,15 @@ public XmlNodeTrx insertTextAsFirstChild(final String value) { final SirixDeweyID id = deweyIDManager.newFirstChildID(); final TextNode node = nodeFactory.createTextNode(parentKey, leftSibKey, rightSibKey, textValue, useTextCompression, id); + final long nodeKey = node.getNodeKey(); // Adapt local nodes and hashes. - nodeReadOnlyTrx.setCurrentNode(node); adaptForInsert(node, InsertPos.ASFIRSTCHILD); - nodeReadOnlyTrx.setCurrentNode(node); - nodeHashing.adaptHashesWithAdd(); + nodeHashing.adaptHashesWithAdd(nodeKey); + moveTo(nodeKey); // Index text value. - notifyPrimitiveIndexChange(IndexController.ChangeType.INSERT, node, pathNodeKey); + notifyPrimitiveIndexChange(IndexController.ChangeType.INSERT, nodeReadOnlyTrx.getCurrentNode(), pathNodeKey); return this; } finally { @@ -1002,22 +1015,22 @@ public XmlNodeTrx insertTextAsLeftSibling(final String value) { final SirixDeweyID id = deweyIDManager.newLeftSiblingID(); final TextNode node = nodeFactory.createTextNode(parentKey, leftSibKey, rightSibKey, textValue, useTextCompression, id); + final long nodeKey = node.getNodeKey(); // Adapt local nodes and hashes. - nodeReadOnlyTrx.setCurrentNode(node); adaptForInsert(node, InsertPos.ASLEFTSIBLING); - nodeReadOnlyTrx.setCurrentNode(node); - nodeHashing.adaptHashesWithAdd(); + nodeHashing.adaptHashesWithAdd(nodeKey); // Get the path node key. + moveTo(nodeKey); moveToParent(); final long pathNodeKey = isElement() ? getNameNode().getPathNodeKey() : -1; - nodeReadOnlyTrx.setCurrentNode(node); + moveTo(nodeKey); // Index text value. - notifyPrimitiveIndexChange(IndexController.ChangeType.INSERT, node, pathNodeKey); + notifyPrimitiveIndexChange(IndexController.ChangeType.INSERT, nodeReadOnlyTrx.getCurrentNode(), pathNodeKey); return this; } finally { @@ -1080,22 +1093,22 @@ public XmlNodeTrx insertTextAsRightSibling(final String value) { final SirixDeweyID id = deweyIDManager.newRightSiblingID(); final TextNode node = nodeFactory.createTextNode(parentKey, leftSibKey, rightSibKey, textValue, useTextCompression, id); + final long nodeKey = node.getNodeKey(); // Adapt local nodes and hashes. - nodeReadOnlyTrx.setCurrentNode(node); adaptForInsert(node, InsertPos.ASRIGHTSIBLING); - nodeReadOnlyTrx.setCurrentNode(node); - nodeHashing.adaptHashesWithAdd(); + nodeHashing.adaptHashesWithAdd(nodeKey); // Get the path node key. + moveTo(nodeKey); moveToParent(); final long pathNodeKey = isElement() ? getNameNode().getPathNodeKey() : -1; - nodeReadOnlyTrx.setCurrentNode(node); + moveTo(nodeKey); // Index text value. - notifyPrimitiveIndexChange(IndexController.ChangeType.INSERT, node, pathNodeKey); + notifyPrimitiveIndexChange(IndexController.ChangeType.INSERT, nodeReadOnlyTrx.getCurrentNode(), pathNodeKey); return this; } finally { @@ -1175,16 +1188,17 @@ public XmlNodeTrx insertAttribute(final QNm name, @NonNull final String value, @ final SirixDeweyID id = deweyIDManager.newAttributeID(); final AttributeNode node = nodeFactory.createAttributeNode(elementKey, name, attValue, pathNodeKey, id); + final long nodeKey = node.getNodeKey(); - final Node parentNode = storageEngineWriter.prepareRecordForModification(node.getParentKey(), IndexType.DOCUMENT, -1); - ((ElementNode) parentNode).insertAttribute(node.getNodeKey()); + final Node parentNode = storageEngineWriter.prepareRecordForModification(elementKey, IndexType.DOCUMENT, -1); + ((ElementNode) parentNode).insertAttribute(nodeKey); persistUpdatedRecord(parentNode); - nodeReadOnlyTrx.setCurrentNode(node); + moveTo(nodeKey); nodeHashing.adaptHashesWithAdd(); // Index text value. - notifyPrimitiveIndexChange(IndexController.ChangeType.INSERT, node, pathNodeKey); + notifyPrimitiveIndexChange(IndexController.ChangeType.INSERT, nodeReadOnlyTrx.getCurrentNode(), pathNodeKey); if (move == Movement.TOPARENT) { moveToParent(); @@ -1235,12 +1249,13 @@ public XmlNodeTrx insertNamespace(@NonNull final QNm name, @NonNull final Moveme final SirixDeweyID id = deweyIDManager.newNamespaceID(); final NamespaceNode node = nodeFactory.createNamespaceNode(elementKey, name, pathNodeKey, id); + final long nodeKey = node.getNodeKey(); - final Node parentNode = storageEngineWriter.prepareRecordForModification(node.getParentKey(), IndexType.DOCUMENT, -1); - ((ElementNode) parentNode).insertNamespace(node.getNodeKey()); + final Node parentNode = storageEngineWriter.prepareRecordForModification(elementKey, IndexType.DOCUMENT, -1); + ((ElementNode) parentNode).insertNamespace(nodeKey); persistUpdatedRecord(parentNode); - nodeReadOnlyTrx.setCurrentNode(node); + moveTo(nodeKey); nodeHashing.adaptHashesWithAdd(); if (move == Movement.TOPARENT) { moveToParent(); @@ -1475,12 +1490,9 @@ public XmlNodeTrx setName(final QNm name) { if (!getName().equals(name)) { checkAccessAndCommit(); - final NameNode node; - if (currentKind == NodeKind.ELEMENT || currentKind == NodeKind.PROCESSING_INSTRUCTION) { - node = (NameNode) nodeReadOnlyTrx.getStructuralNode(); - } else { - node = (NameNode) nodeReadOnlyTrx.getCurrentNode(); - } + // Get a TIL-owned copy via prepareRecordForModification (proper COW). + final NameNode node = + (NameNode) storageEngineWriter.prepareRecordForModification(getNodeKey(), IndexType.DOCUMENT, -1); final long oldHash = node.computeHash(bytes); // Remove old keys from mapping. @@ -1505,6 +1517,7 @@ public XmlNodeTrx setName(final QNm name) { : -1; // Set new keys for current node. + final long savedNodeKey = node.getNodeKey(); node.setLocalNameKey(localNameKey); node.setURIKey(uriKey); node.setPrefixKey(prefixKey); @@ -1515,13 +1528,18 @@ public XmlNodeTrx setName(final QNm name) { PathSummaryWriter.OPType.SETNAME); } + // Re-acquire the record: adaptPathForChangedNode may have rebound the write + // singleton to a different node via resetPathNodeKey → prepareRecordForModification. + final NameNode node2 = + (NameNode) storageEngineWriter.prepareRecordForModification(savedNodeKey, IndexType.DOCUMENT, -1); + // Set path node key. - node.setPathNodeKey(buildPathSummary + node2.setPathNodeKey(buildPathSummary ? pathSummaryWriter.getNodeKey() : 0); - nodeReadOnlyTrx.setCurrentNode((ImmutableXmlNode) node); - persistUpdatedRecord(node); + nodeReadOnlyTrx.setCurrentNode((ImmutableXmlNode) node2); + persistUpdatedRecord(node2); nodeHashing.adaptHashedWithUpdate(oldHash); } @@ -1560,13 +1578,11 @@ public XmlNodeTrx setValue(final String value) { final long pathNodeKey = getPathNodeKey(); moveTo(nodeKey); - final ValueNode node; - if (currentKind == NodeKind.TEXT || currentKind == NodeKind.COMMENT - || currentKind == NodeKind.PROCESSING_INSTRUCTION) { - node = (ValueNode) nodeReadOnlyTrx.getStructuralNode(); - } else { - node = (ValueNode) nodeReadOnlyTrx.getCurrentNode(); - } + // Get a TIL-owned copy via prepareRecordForModification (proper COW). + // This ensures mutations don't leak to read-only transactions that share + // the same cached page reference. + final ValueNode node = + (ValueNode) storageEngineWriter.prepareRecordForModification(nodeKey, IndexType.DOCUMENT, -1); // Remove old value from indexes before mutating the node. notifyPrimitiveIndexChange(IndexController.ChangeType.DELETE, (ImmutableNode) node, pathNodeKey); final long oldHash = node.computeHash(bytes); @@ -2074,6 +2090,14 @@ protected AbstractNodeHashing reInstantiat @Override protected XmlNodeFactory reInstantiateNodeFactory(StorageEngineWriter storageEngineWriter) { - return new XmlNodeFactoryImpl(resourceSession.getResourceConfig().nodeHashFunction, storageEngineWriter); + final var factory = new XmlNodeFactoryImpl( + resourceSession.getResourceConfig().nodeHashFunction, storageEngineWriter); + wireWriteSingletonBinder(factory, storageEngineWriter); + return factory; + } + + private static void wireWriteSingletonBinder(final XmlNodeFactoryImpl factory, + final StorageEngineWriter storageEngineWriter) { + storageEngineWriter.setWriteSingletonBinder(factory::bindWriteSingleton); } } diff --git a/bundles/sirix-core/src/main/java/io/sirix/access/trx/page/AbstractForwardingStorageEngineWriter.java b/bundles/sirix-core/src/main/java/io/sirix/access/trx/page/AbstractForwardingStorageEngineWriter.java index a5f27d9c1..a916e361f 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/access/trx/page/AbstractForwardingStorageEngineWriter.java +++ b/bundles/sirix-core/src/main/java/io/sirix/access/trx/page/AbstractForwardingStorageEngineWriter.java @@ -46,8 +46,8 @@ public V prepareRecordForModification(@NonNegative long r } @Override - public void updateRecordSlot(@NonNull DataRecord record, @NonNull IndexType indexType, int index) { - delegate().updateRecordSlot(record, indexType, index); + public void persistRecord(@NonNull DataRecord record, @NonNull IndexType indexType, int index) { + delegate().persistRecord(record, indexType, index); } @Override diff --git a/bundles/sirix-core/src/main/java/io/sirix/access/trx/page/HOTTrieWriter.java b/bundles/sirix-core/src/main/java/io/sirix/access/trx/page/HOTTrieWriter.java index dcd414df4..ecd65a590 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/access/trx/page/HOTTrieWriter.java +++ b/bundles/sirix-core/src/main/java/io/sirix/access/trx/page/HOTTrieWriter.java @@ -507,14 +507,13 @@ public byte[] handleLeafSplit(@NonNull StorageEngineWriter storageEngineReader, } else { // Root split - create new BiNode as root // CRITICAL: When pathDepth=0, leafRef may be the same object as rootReference. - // We need to create a SEPARATE reference for the left child to avoid circular references. + // We need a SEPARATE reference for the left child, and it MUST be in the log + // so that HOTIndirectPage.commit() can find and write it to disk. PageReference leftChildRef; if (leafRef == rootReference) { - // Create a new reference for the left child that points to the leaf's log entry + // Put the left child in the log so commit can find it by identity leftChildRef = new PageReference(); - leftChildRef.setLogKey(leafRef.getLogKey()); - leftChildRef.setKey(fullPage.getPageKey()); - leftChildRef.setPage(fullPage); + log.put(leftChildRef, PageContainer.getInstance(fullPage, fullPage)); } else { leftChildRef = leafRef; } diff --git a/bundles/sirix-core/src/main/java/io/sirix/access/trx/page/NodeStorageEngineReader.java b/bundles/sirix-core/src/main/java/io/sirix/access/trx/page/NodeStorageEngineReader.java index cd660c93c..7e8adcbfc 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/access/trx/page/NodeStorageEngineReader.java +++ b/bundles/sirix-core/src/main/java/io/sirix/access/trx/page/NodeStorageEngineReader.java @@ -30,36 +30,21 @@ import io.sirix.api.NodeTrx; import io.sirix.api.StorageEngineReader; import io.sirix.api.ResourceSession; -import io.sirix.cache.BufferManager; -import io.sirix.cache.Cache; -import io.sirix.cache.FrameReusedException; -import io.sirix.cache.IndexLogKey; -import io.sirix.cache.PageContainer; +import io.sirix.cache.*; import io.sirix.cache.PageGuard; -import io.sirix.cache.RevisionRootPageCacheKey; -import io.sirix.cache.TransactionIntentLog; import io.sirix.exception.SirixIOException; import io.sirix.index.IndexType; import io.sirix.io.Reader; import io.sirix.node.DeletedNode; import io.sirix.node.MemorySegmentBytesIn; import io.sirix.node.NodeKind; +import io.sirix.node.SirixDeweyID; import io.sirix.node.interfaces.DataRecord; +import io.sirix.node.interfaces.FlyweightNode; +import io.sirix.node.interfaces.Node; import io.sirix.node.json.ObjectStringNode; import io.sirix.node.json.StringNode; -import io.sirix.page.CASPage; -import io.sirix.page.DeweyIDPage; -import io.sirix.page.HOTIndirectPage; -import io.sirix.page.HOTLeafPage; -import io.sirix.page.IndirectPage; -import io.sirix.page.KeyValueLeafPage; -import io.sirix.page.NamePage; -import io.sirix.page.OverflowPage; -import io.sirix.page.PageReference; -import io.sirix.page.PathPage; -import io.sirix.page.PathSummaryPage; -import io.sirix.page.RevisionRootPage; -import io.sirix.page.UberPage; +import io.sirix.page.*; import io.sirix.page.interfaces.KeyValuePage; import io.sirix.page.interfaces.Page; import io.sirix.page.interfaces.PageFragmentKey; @@ -84,7 +69,7 @@ import static java.util.Objects.requireNonNull; /** - * Storage engine reader. The only thing shared amongst transactions is the resource session. + * Page read-only transaction. The only thing shared amongst transactions is the resource manager. * Everything else is exclusive to this transaction. It is required that only a single thread has * access to this transaction. */ @@ -94,13 +79,12 @@ public final class NodeStorageEngineReader implements StorageEngineReader { /** * Enable path summary cache debugging. - * * @see DiagnosticSettings#PATH_SUMMARY_DEBUG */ private static final boolean DEBUG_PATH_SUMMARY = DiagnosticSettings.PATH_SUMMARY_DEBUG; private record RecordPage(int index, IndexType indexType, long recordPageKey, int revision, - PageReference pageReference, KeyValueLeafPage page) { + PageReference pageReference, KeyValueLeafPage page) { } /** @@ -119,12 +103,12 @@ private record RecordPage(int index, IndexType indexType, long recordPageKey, in final InternalResourceSession resourceSession; /** - * The revision number, this storage engine reader is bound to. + * The revision number, this page trx is bound to. */ private final int revisionNumber; /** - * Determines if storage engine reader is closed or not. + * Determines if page reading transaction is closed or not. */ private volatile boolean isClosed; @@ -159,19 +143,22 @@ private record RecordPage(int index, IndexType indexType, long recordPageKey, in private final long resourceId; /** - * Epoch tracker ticket for this transaction (for MVCC-aware eviction). Registered when transaction - * opens, deregistered when it closes. + * Epoch tracker ticket for this transaction (for MVCC-aware eviction). + * Registered when transaction opens, deregistered when it closes. */ private final RevisionEpochTracker.Ticket epochTicket; /** * Current page guard - protects the page where cursor is currently positioned. *

- * Guard lifecycle: - Acquired when cursor moves to a page - Released when cursor moves to a - * DIFFERENT page - Released on transaction close + * Guard lifecycle: + * - Acquired when cursor moves to a page + * - Released when cursor moves to a DIFFERENT page + * - Released on transaction close *

- * This matches database cursor semantics: only the "current" page is guarded. Node keys are - * primitives (copied from MemorySegments), so old pages can be evicted after cursor moves away. + * This matches database cursor semantics: only the "current" page is guarded. + * Node keys are primitives (copied from MemorySegments), so old pages can be + * evicted after cursor moves away. */ private PageGuard currentPageGuard; @@ -186,8 +173,9 @@ private record RecordPage(int index, IndexType indexType, long recordPageKey, in private final NamePage namePage; /** - * Most recently read pages by type and index. Using specific fields instead of generic cache for - * clear ownership and lifecycle. Index-aware: NAME/PATH/CAS can have multiple indexes (0-3). + * Most recently read pages by type and index. + * Using specific fields instead of generic cache for clear ownership and lifecycle. + * Index-aware: NAME/PATH/CAS can have multiple indexes (0-3). */ private RecordPage mostRecentDocumentPage; private RecordPage mostRecentChangedNodesPage; @@ -199,21 +187,21 @@ private record RecordPage(int index, IndexType indexType, long recordPageKey, in private RecordPage mostRecentDeweyIdPage; /** - * Reusable IndexLogKey to avoid allocations on every getRecord/lookupSlot call. Safe to reuse - * because this transaction is single-threaded (see class javadoc). + * Reusable IndexLogKey to avoid allocations on every getRecord/lookupSlot call. + * Safe to reuse because this transaction is single-threaded (see class javadoc). */ private final IndexLogKey reusableIndexLogKey = new IndexLogKey(null, 0, 0, 0); /** * Standard constructor. * - * @param trxId the transaction-ID. - * @param resourceSession the resource session - * @param uberPage {@link UberPage} to start reading from - * @param revision key of revision to read from uber page - * @param reader to read stored pages for this transaction + * @param trxId the transaction-ID. + * @param resourceSession the resource manager + * @param uberPage {@link UberPage} to start reading from + * @param revision key of revision to read from uber page + * @param reader to read stored pages for this transaction * @param resourceBufferManager caches in-memory reconstructed pages - * @param trxIntentLog the transaction intent log (can be {@code null}) + * @param trxIntentLog the transaction intent log (can be {@code null}) * @throws SirixIOException if reading of the persistent storage fails */ public NodeStorageEngineReader(final int trxId, @@ -260,7 +248,7 @@ private Page loadPage(final PageReference reference) { // logKey might still be set, so don't assert it's NULL_ID_INT } - // if (trxIntentLog == null) { + // if (trxIntentLog == null) { // REMOVED INCORRECT ASSERTION: logKey can be != NULL_ID_INT if page was in TIL then cleared // assert reference.getLogKey() == Constants.NULL_ID_INT; page = resourceBufferManager.getPageCache().get(reference, (_, _) -> { @@ -275,18 +263,17 @@ private Page loadPage(final PageReference reference) { reference.setPage(page); } return page; - // } + // } - // if (reference.getKey() != Constants.NULL_ID_LONG || reference.getLogKey() != - // Constants.NULL_ID_INT) { - // page = pageReader.read(reference, resourceSession.getResourceConfig()); - // } + // if (reference.getKey() != Constants.NULL_ID_LONG || reference.getLogKey() != Constants.NULL_ID_INT) { + // page = pageReader.read(reference, resourceSession.getResourceConfig()); + // } // - // if (page != null) { - // putIntoPageCache(reference, page); - // reference.setPage(page); - // } - // return page; + // if (page != null) { + // putIntoPageCache(reference, page); + // reference.setPage(page); + // } + // return page; } @Override @@ -298,9 +285,7 @@ public boolean hasTrxIntentLog() { private Page getFromTrxIntentLog(PageReference reference) { // Try to get it from the transaction log if it's present. final PageContainer cont = trxIntentLog.get(reference); - return cont == null - ? null - : cont.getComplete(); + return cont == null ? null : cont.getComplete(); } @Override @@ -349,14 +334,13 @@ public V getRecord(final long recordKey, @NonNull final I // OPTIMIZATION: Reuse IndexLogKey instance to avoid allocation on every getRecord call reusableIndexLogKey.setIndexType(indexType) - .setRecordPageKey(recordPageKey) - .setIndexNumber(index) - .setRevisionNumber(revisionNumber); + .setRecordPageKey(recordPageKey) + .setIndexNumber(index) + .setRevisionNumber(revisionNumber); // $CASES-OMITTED$ final PageReferenceToPage pageReferenceToPage = switch (indexType) { - case DOCUMENT, CHANGED_NODES, RECORD_TO_REVISIONS, PATH_SUMMARY, PATH, CAS, NAME -> - getRecordPage(reusableIndexLogKey); + case DOCUMENT, CHANGED_NODES, RECORD_TO_REVISIONS, PATH_SUMMARY, PATH, CAS, NAME -> getRecordPage(reusableIndexLogKey); default -> throw new IllegalStateException(); }; @@ -366,7 +350,7 @@ public V getRecord(final long recordKey, @NonNull final I final var dataRecord = getValue(((KeyValueLeafPage) pageReferenceToPage.page), recordKey); - // noinspection unchecked + //noinspection unchecked return (V) checkItemIfDeleted(dataRecord); } @@ -375,60 +359,102 @@ public DataRecord getValue(final KeyValuePage page, final final var offset = StorageEngineReader.recordPageOffset(nodeKey); DataRecord record = page.getRecord(offset); if (record == null) { - var data = page.getSlot(offset); - if (data != null) { - record = getDataRecord(nodeKey, offset, data, page); + // Unified page path: check directory for flyweight vs legacy format + if (page instanceof KeyValueLeafPage kvlPage) { + record = getRecordFromSlottedPage(kvlPage, nodeKey, offset); + } else { + var data = page.getSlot(offset); + if (data != null) { + record = getDataRecord(nodeKey, offset, data, page); + } } if (record != null) { return record; } + // Overflow page fallback try { final PageReference reference = page.getPageReference(nodeKey); if (reference != null && reference.getKey() != Constants.NULL_ID_LONG) { - data = ((OverflowPage) pageReader.read(reference, resourceSession.getResourceConfig())).getData(); + final var data = ((OverflowPage) pageReader.read(reference, resourceSession.getResourceConfig())).getData(); + record = getDataRecord(nodeKey, offset, data, page); } else { return null; } } catch (final SirixIOException e) { return null; } - record = getDataRecord(nodeKey, offset, data, page); + } else if (page instanceof KeyValueLeafPage kvlPage) { + // Record was found in records[] cache. Ensure FSST symbol table is propagated + // (needed when a cached page from the write transaction is reused by a read session + // — the FSST table is built at commit time but records[] may already be populated) + propagateFsstSymbolTableToRecord(record, kvlPage); } return record; } + /** + * Get a record from a slotted page. Flyweight records (nodeKindId > 0) are + * created via FlyweightNodeFactory and bound directly to page memory. + * Legacy records (nodeKindId == 0) are deserialized from the heap bytes. + */ @SuppressWarnings({"unchecked", "rawtypes"}) - private DataRecord getDataRecord(long key, int offset, MemorySegment data, KeyValuePage page) { - final boolean fixedSlotFormat = page instanceof KeyValueLeafPage kvPage && kvPage.isFixedSlotFormat(offset); - if (fixedSlotFormat) { - throw new IllegalStateException( - "Fixed-slot bytes must be read through singleton cursor access (moveTo/lookupSlotWithGuard) " - + "or writer-specific fixed-slot materialization (key=" + key + ", slot=" + offset + ")."); + private DataRecord getRecordFromSlottedPage(final KeyValueLeafPage kvlPage, + final long nodeKey, final int offset) { + final MemorySegment slottedPage = kvlPage.getSlottedPage(); + if (!PageLayout.isSlotPopulated(slottedPage, offset)) { + return null; + } + final int nodeKindId = PageLayout.getDirNodeKindId(slottedPage, offset); + if (nodeKindId > 0) { + // Flyweight format: create binding shell and bind to page memory (zero-copy read) + final FlyweightNode fn = FlyweightNodeFactory.createAndBind( + slottedPage, offset, nodeKey, resourceConfig.nodeHashFunction); + // Propagate DeweyID from page to flyweight node (stored inline after record data) + if (resourceConfig.areDeweyIDsStored && fn instanceof Node node) { + final byte[] deweyIdBytes = kvlPage.getDeweyIdAsByteArray(offset); + if (deweyIdBytes != null) { + node.setDeweyID(new SirixDeweyID(deweyIdBytes)); + } + } + // Propagate FSST symbol table to flyweight string nodes for lazy decompression + propagateFsstSymbolTableToRecord((DataRecord) fn, kvlPage); + // Do NOT cache FlyweightNode in page's records[] — pages are shared between transactions. + return (DataRecord) fn; + } else { + // Legacy format in slotted page heap: deserialize normally + final var data = kvlPage.getSlot(offset); + if (data != null) { + final var record = getDataRecord(nodeKey, offset, data, kvlPage); + return record; + } + return null; } + } - final byte[] deweyIdBytes = page.getDeweyIdAsByteArray(offset); - final DataRecord record = deserializeCompactRecord(key, data, deweyIdBytes); + @SuppressWarnings({"unchecked", "rawtypes"}) + private DataRecord getDataRecord(long key, int offset, MemorySegment data, KeyValuePage page) { + var record = resourceConfig.recordPersister.deserialize(new MemorySegmentBytesIn(data), + key, + page.getDeweyIdAsByteArray(offset), + resourceConfig); // Propagate FSST symbol table to string nodes for lazy decompression // Only KeyValueLeafPage has FSST symbol table support if (page instanceof KeyValueLeafPage kvPage) { propagateFsstSymbolTableToRecord(record, kvPage); - kvPage.onRecordRematerialized(); } - // Use raw type to avoid generic mismatch with different KeyValuePage implementations. - ((KeyValuePage) page).setRecord(record); + // Do NOT cache deserialized records in the page's records[] here. + // Pages in the buffer manager are shared between transactions. + // Caching creates shared mutable references that violate snapshot isolation: + // a write transaction mutating the cached record would be visible to + // read-only transactions reading from the same committed page. return record; } - private DataRecord deserializeCompactRecord(final long key, final MemorySegment data, final byte[] deweyIdBytes) { - return resourceConfig.recordPersister.deserialize(new MemorySegmentBytesIn(data), key, deweyIdBytes, - resourceConfig); - } - /** - * Propagate FSST symbol table from page to string nodes. This enables lazy decompression when - * getValue() is called. + * Propagate FSST symbol table from page to string nodes. + * This enables lazy decompression when getValue() is called. */ private void propagateFsstSymbolTableToRecord(DataRecord record, KeyValueLeafPage page) { if (record == null || page == null) { @@ -436,29 +462,27 @@ private void propagateFsstSymbolTableToRecord(DataRecord record, KeyValueLeafPag } final byte[] fsstSymbolTable = page.getFsstSymbolTable(); if (fsstSymbolTable != null && fsstSymbolTable.length > 0) { - final byte[][] parsedSymbols = page.getParsedFsstSymbols(); if (record instanceof StringNode stringNode) { - stringNode.setFsstSymbolTable(fsstSymbolTable, parsedSymbols); + stringNode.setFsstSymbolTable(fsstSymbolTable); } else if (record instanceof ObjectStringNode objectStringNode) { - objectStringNode.setFsstSymbolTable(fsstSymbolTable, parsedSymbols); + objectStringNode.setFsstSymbolTable(fsstSymbolTable); } } } // ==================== FLYWEIGHT CURSOR SUPPORT ==================== - + /** - * Record containing slot location data for zero-allocation access. Holds all information needed to - * read node fields directly from memory. + * Record containing slot location data for zero-allocation access. + * Holds all information needed to read node fields directly from memory. * - * @param page the KeyValueLeafPage containing the slot + * @param page the KeyValueLeafPage containing the slot * @param offset the slot offset within the page (for DeweyID lookup) - * @param data the MemorySegment containing the serialized node data - * @param guard the PageGuard protecting the page from eviction + * @param data the MemorySegment containing the serialized node data + * @param guard the PageGuard protecting the page from eviction */ - public record SlotLocation(KeyValueLeafPage page, int offset, MemorySegment data, PageGuard guard) { - } - + public record SlotLocation(KeyValueLeafPage page, int offset, MemorySegment data, PageGuard guard) {} + /** * Result of lookupSlotOrCached - either a cached record or a slot location. */ @@ -466,19 +490,18 @@ public record SlotOrCachedResult(DataRecord cachedRecord, SlotLocation slotLocat public boolean hasCachedRecord() { return cachedRecord != null; } - public boolean hasSlotLocation() { return slotLocation != null; } } - + /** - * Lookup a node, returning cached record if available, otherwise slot location. This does ONE page - * lookup and checks the cache first, avoiding double lookups. + * Lookup a node, returning cached record if available, otherwise slot location. + * This does ONE page lookup and checks the cache first, avoiding double lookups. * * @param recordKey the node key to look up * @param indexType the index type - * @param index the index number + * @param index the index number * @return SlotOrCachedResult with either cachedRecord or slotLocation, or both null if not found */ public SlotOrCachedResult lookupSlotOrCached(final long recordKey, @NonNull final IndexType indexType, @@ -493,14 +516,13 @@ public SlotOrCachedResult lookupSlotOrCached(final long recordKey, @NonNull fina final long recordPageKey = pageKey(recordKey, indexType); // OPTIMIZATION: Reuse IndexLogKey instance to avoid allocation reusableIndexLogKey.setIndexType(indexType) - .setRecordPageKey(recordPageKey) - .setIndexNumber(index) - .setRevisionNumber(revisionNumber); + .setRecordPageKey(recordPageKey) + .setIndexNumber(index) + .setRevisionNumber(revisionNumber); // Get the page reference (uses cache) - ONE lookup for both paths final PageReferenceToPage pageReferenceToPage = switch (indexType) { - case DOCUMENT, CHANGED_NODES, RECORD_TO_REVISIONS, PATH_SUMMARY, PATH, CAS, NAME -> - getRecordPage(reusableIndexLogKey); + case DOCUMENT, CHANGED_NODES, RECORD_TO_REVISIONS, PATH_SUMMARY, PATH, CAS, NAME -> getRecordPage(reusableIndexLogKey); default -> null; }; @@ -521,7 +543,7 @@ public SlotOrCachedResult lookupSlotOrCached(final long recordKey, @NonNull fina // Record was deleted - return not found return new SlotOrCachedResult(null, null); } - + // Not cached - acquire guard and return slot location page.acquireGuard(); @@ -557,29 +579,28 @@ public SlotOrCachedResult lookupSlotOrCached(final long recordKey, @NonNull fina } /** - * Lookup a slot directly without deserializing to a node object. This is the core method for - * zero-allocation flyweight cursor access. + * Lookup a slot directly without deserializing to a node object. + * This is the core method for zero-allocation flyweight cursor access. *

- * IMPORTANT: The returned PageGuard MUST be closed when the slot is no longer needed. Failure to - * close the guard will prevent page eviction and cause memory issues. + * IMPORTANT: The returned PageGuard MUST be closed when the slot is no longer needed. + * Failure to close the guard will prevent page eviction and cause memory issues. *

* Usage: - * * 

{@code
    * var location = reader.lookupSlotWithGuard(nodeKey, IndexType.DOCUMENT, -1);
    * if (location != null) {
-   *   try {
-   *     // Read directly from location.data()
-   *     long parentKey = DeltaVarIntCodec.decodeDeltaFromSegment(location.data(), offset, nodeKey);
-   *   } finally {
-   *     location.guard().close();
-   *   }
+   *     try {
+   *         // Read directly from location.data()
+   *         long parentKey = DeltaVarIntCodec.decodeDeltaFromSegment(location.data(), offset, nodeKey);
+   *     } finally {
+   *         location.guard().close();
+   *     }
    * }
    * }
* * @param recordKey the node key to lookup * @param indexType the index type (typically DOCUMENT for regular nodes) - * @param index the index number (-1 for DOCUMENT) + * @param index the index number (-1 for DOCUMENT) * @return SlotLocation with page guard, or null if not found */ public SlotLocation lookupSlotWithGuard(long recordKey, IndexType indexType, int index) { @@ -593,14 +614,13 @@ public SlotLocation lookupSlotWithGuard(long recordKey, IndexType indexType, int final long recordPageKey = pageKey(recordKey, indexType); // OPTIMIZATION: Reuse IndexLogKey instance to avoid allocation reusableIndexLogKey.setIndexType(indexType) - .setRecordPageKey(recordPageKey) - .setIndexNumber(index) - .setRevisionNumber(revisionNumber); + .setRecordPageKey(recordPageKey) + .setIndexNumber(index) + .setRevisionNumber(revisionNumber); // Get the page reference final PageReferenceToPage pageReferenceToPage = switch (indexType) { - case DOCUMENT, CHANGED_NODES, RECORD_TO_REVISIONS, PATH_SUMMARY, PATH, CAS, NAME -> - getRecordPage(reusableIndexLogKey); + case DOCUMENT, CHANGED_NODES, RECORD_TO_REVISIONS, PATH_SUMMARY, PATH, CAS, NAME -> getRecordPage(reusableIndexLogKey); default -> throw new IllegalStateException("Unsupported index type: " + indexType); }; @@ -755,11 +775,11 @@ public record PageReferenceToPage(PageReference reference, Page page) { /** * Prefetch a page into the cache without blocking on the result. *

- * This method loads the specified page into the buffer cache so that subsequent accesses to nodes - * on that page will be cache hits. + * This method loads the specified page into the buffer cache so that + * subsequent accesses to nodes on that page will be cache hits. *

- * Called by prefetching axes (e.g., PrefetchingDescendantAxis) to asynchronously load pages that - * will be needed soon. + * Called by prefetching axes (e.g., PrefetchingDescendantAxis) to + * asynchronously load pages that will be needed soon. * * @param recordPageKey the page key to prefetch * @param indexType the index type (typically DOCUMENT) @@ -778,9 +798,9 @@ public PageReferenceToPage getRecordPage(@NonNull IndexLogKey indexLogKey) { // This prevents TOCTOU race where page is closed between check and guard acquisition closeCurrentPageGuard(); page.acquireGuard(); - + // Now check if page is still valid (not closed, memory not released) - if (!page.isClosed() && page.getSlotMemory() != null) { + if (!page.isClosed() && page.getSlottedPage() != null) { currentPageGuard = PageGuard.wrapAlreadyGuarded(page); return new PageReferenceToPage(pathSummaryRecordPage.pageReference, page); } else { @@ -792,8 +812,10 @@ public PageReferenceToPage getRecordPage(@NonNull IndexLogKey indexLogKey) { } // Check the most recent page for this type/index - var cachedPage = getMostRecentPage(indexLogKey.getIndexType(), indexLogKey.getIndexNumber(), - indexLogKey.getRecordPageKey(), indexLogKey.getRevisionNumber()); + var cachedPage = getMostRecentPage(indexLogKey.getIndexType(), + indexLogKey.getIndexNumber(), + indexLogKey.getRecordPageKey(), + indexLogKey.getRevisionNumber()); if (cachedPage != null) { var page = cachedPage.page(); @@ -802,9 +824,9 @@ public PageReferenceToPage getRecordPage(@NonNull IndexLogKey indexLogKey) { // This prevents TOCTOU race where page is closed between check and guard acquisition closeCurrentPageGuard(); page.acquireGuard(); - + // Now check if page is still valid (not closed, memory not released) - if (!page.isClosed() && page.getSlotMemory() != null) { + if (!page.isClosed() && page.getSlottedPage() != null) { currentPageGuard = PageGuard.wrapAlreadyGuarded(page); return new PageReferenceToPage(cachedPage.pageReference, page); } else { @@ -818,7 +840,8 @@ public PageReferenceToPage getRecordPage(@NonNull IndexLogKey indexLogKey) { // Second: Traverse trie. final var pageReferenceToRecordPage = getLeafPageReference(indexLogKey.getRecordPageKey(), - indexLogKey.getIndexNumber(), requireNonNull(indexLogKey.getIndexType())); + indexLogKey.getIndexNumber(), + requireNonNull(indexLogKey.getIndexType())); if (pageReferenceToRecordPage == null) { return null; @@ -844,12 +867,12 @@ public PageReferenceToPage getRecordPage(@NonNull IndexLogKey indexLogKey) { if (DEBUG_PATH_SUMMARY && indexLogKey.getIndexType() == IndexType.PATH_SUMMARY && page instanceof KeyValueLeafPage kvp) { - LOGGER.debug("[PATH_SUMMARY-NORMAL] -> Got page from cache: pageKey={}, revision={}", kvp.getPageKey(), - kvp.getRevision()); + LOGGER.debug("[PATH_SUMMARY-NORMAL] -> Got page from cache: pageKey={}, revision={}", + kvp.getPageKey(), + kvp.getRevision()); } - // CRITICAL: Handle case where page doesn't exist (e.g., temporal queries accessing non-existent - // revisions) + // CRITICAL: Handle case where page doesn't exist (e.g., temporal queries accessing non-existent revisions) if (page == null) { // Page doesn't exist for this revision/index - this can happen with temporal queries // Return null to signal page not found (caller should handle gracefully) @@ -863,8 +886,7 @@ public PageReferenceToPage getRecordPage(@NonNull IndexLogKey indexLogKey) { // PATH_SUMMARY bypass for write transactions - REQUIRED due to cache key limitations // RecordPageCache uses PageReference (key + logKey) as cache key, which doesn't include revision. - // Different revisions of the same page can have the same PageReference → cache returns wrong - // revision. + // Different revisions of the same page can have the same PageReference → cache returns wrong revision. // Bypass loads directly from disk to avoid stale cached pages. if (DEBUG_PATH_SUMMARY) { LOGGER.debug("\n[PATH_SUMMARY-DECISION] Using bypass (write trx):"); @@ -908,15 +930,9 @@ private RecordPage getMostRecentPage(IndexType indexType, int index, long record case CHANGED_NODES -> mostRecentChangedNodesPage; case RECORD_TO_REVISIONS -> mostRecentRecordToRevisionsPage; case PATH_SUMMARY -> pathSummaryRecordPage; - case PATH -> index < mostRecentPathPages.length - ? mostRecentPathPages[index] - : null; - case CAS -> index < mostRecentCasPages.length - ? mostRecentCasPages[index] - : null; - case NAME -> index < mostRecentNamePages.length - ? mostRecentNamePages[index] - : null; + case PATH -> index < mostRecentPathPages.length ? mostRecentPathPages[index] : null; + case CAS -> index < mostRecentCasPages.length ? mostRecentCasPages[index] : null; + case NAME -> index < mostRecentNamePages.length ? mostRecentNamePages[index] : null; case DEWEYID_TO_RECORDID -> mostRecentDeweyIdPage; default -> null; }; @@ -955,27 +971,21 @@ private void setMostRecentPage(IndexType indexType, int index, RecordPage page) yield old; } case PATH -> { - RecordPage old = index < mostRecentPathPages.length - ? mostRecentPathPages[index] - : null; + RecordPage old = index < mostRecentPathPages.length ? mostRecentPathPages[index] : null; if (index < mostRecentPathPages.length) { mostRecentPathPages[index] = page; } yield old; } case CAS -> { - RecordPage old = index < mostRecentCasPages.length - ? mostRecentCasPages[index] - : null; + RecordPage old = index < mostRecentCasPages.length ? mostRecentCasPages[index] : null; if (index < mostRecentCasPages.length) { mostRecentCasPages[index] = page; } yield old; } case NAME -> { - RecordPage old = index < mostRecentNamePages.length - ? mostRecentNamePages[index] - : null; + RecordPage old = index < mostRecentNamePages.length ? mostRecentNamePages[index] : null; if (index < mostRecentNamePages.length) { mostRecentNamePages[index] = page; } @@ -998,14 +1008,16 @@ private void setMostRecentPage(IndexType indexType, int index, RecordPage page) /** * Close a mostRecent page if it has been orphaned (evicted from cache). *

- * Pages still in cache will be closed by the cache eviction process. Orphaned pages (no longer in - * cache) need to have any remaining guards released and then be closed. + * Pages still in cache will be closed by the cache eviction process. + * Orphaned pages (no longer in cache) need to have any remaining guards released + * and then be closed. *

- * IMPORTANT: For orphaned pages (not in cache), any remaining guards must be from this transaction - * since: 1. Pages can only be evicted/replaced in cache if guardCount == 0 2. If a page has guards - * and is not in cache, those guards are from transactions that hold mostRecent references to a page - * instance that was replaced in cache 3. When this transaction closes, we must release our guard to - * allow the page to close + * IMPORTANT: For orphaned pages (not in cache), any remaining guards must be from + * this transaction since: + * 1. Pages can only be evicted/replaced in cache if guardCount == 0 + * 2. If a page has guards and is not in cache, those guards are from transactions + * that hold mostRecent references to a page instance that was replaced in cache + * 3. When this transaction closes, we must release our guard to allow the page to close * * @param recordPage the record page to potentially close */ @@ -1046,9 +1058,9 @@ private void closeMostRecentPageIfOrphaned(RecordPage recordPage) { /** * Load a page from the buffer manager's cache, or from storage if not cached. *

- * Uses atomic compute() to prevent race conditions between cache lookup and guard acquisition. - * Guards are acquired inside the compute block to ensure the page cannot be evicted before this - * transaction has protected it. + * Uses atomic compute() to prevent race conditions between cache lookup and + * guard acquisition. Guards are acquired inside the compute block to ensure + * the page cannot be evicted before this transaction has protected it. * * @param indexLogKey the index log key for lookup * @param pageReferenceToRecordPage reference to the page @@ -1057,8 +1069,8 @@ private void closeMostRecentPageIfOrphaned(RecordPage recordPage) { @Nullable private Page getFromBufferManager(@NonNull IndexLogKey indexLogKey, PageReference pageReferenceToRecordPage) { if (DEBUG_PATH_SUMMARY && indexLogKey.getIndexType() == IndexType.PATH_SUMMARY && LOGGER.isDebugEnabled()) { - LOGGER.debug("Path summary cache lookup: key={}, revision={}", pageReferenceToRecordPage.getKey(), - indexLogKey.getRevisionNumber()); + LOGGER.debug("Path summary cache lookup: key={}, revision={}", + pageReferenceToRecordPage.getKey(), indexLogKey.getRevisionNumber()); } final ResourceConfiguration config = resourceSession.getResourceConfig(); @@ -1067,8 +1079,8 @@ private Page getFromBufferManager(@NonNull IndexLogKey indexLogKey, PageReferenc // This saves 100% of the allocation and copy overhead for reads if (config.versioningType == VersioningType.FULL) { KeyValueLeafPage page = resourceBufferManager.getRecordPageCache() - .getOrLoadAndGuard(pageReferenceToRecordPage, - ref -> (KeyValueLeafPage) pageReader.read(ref, config)); + .getOrLoadAndGuard(pageReferenceToRecordPage, + ref -> (KeyValueLeafPage) pageReader.read(ref, config)); if (page != null) { pageReferenceToRecordPage.setPage(page); @@ -1079,10 +1091,9 @@ private Page getFromBufferManager(@NonNull IndexLogKey indexLogKey, PageReferenc } // Other versioning types: load fragments → combine → cache - KeyValueLeafPage page = - resourceBufferManager.getRecordPageCache() - .getOrLoadAndGuard(pageReferenceToRecordPage, - ref -> (KeyValueLeafPage) loadDataPageFromDurableStorageAndCombinePageFragments(ref)); + KeyValueLeafPage page = resourceBufferManager.getRecordPageCache() + .getOrLoadAndGuard(pageReferenceToRecordPage, + ref -> (KeyValueLeafPage) loadDataPageFromDurableStorageAndCombinePageFragments(ref)); if (page != null) { pageReferenceToRecordPage.setPage(page); @@ -1104,7 +1115,9 @@ private void setMostRecentlyReadRecordPage(@NonNull IndexLogKey indexLogKey, @No if (DEBUG_PATH_SUMMARY && recordPage != null) { LOGGER.debug( "[PATH_SUMMARY-REPLACE] Replacing old pathSummaryRecordPage: oldPageKey={}, newPageKey={}, trxIntentLog={}", - pathSummaryRecordPage.page.getPageKey(), recordPage.getPageKey(), (trxIntentLog != null)); + pathSummaryRecordPage.page.getPageKey(), + recordPage.getPageKey(), + (trxIntentLog != null)); } if (trxIntentLog == null) { @@ -1120,24 +1133,33 @@ private void setMostRecentlyReadRecordPage(@NonNull IndexLogKey indexLogKey, @No // But if bypass is disabled for testing, they might be cached // Remove from cache before closing to prevent "closed page in cache" errors pathSummaryRecordPage.pageReference.setPage(null); - // resourceBufferManager.getRecordPageCache().remove(pathSummaryRecordPage.pageReference); + //resourceBufferManager.getRecordPageCache().remove(pathSummaryRecordPage.pageReference); if (!pathSummaryRecordPage.page.isClosed()) { if (DEBUG_PATH_SUMMARY) { LOGGER.debug("[PATH_SUMMARY-REPLACE] -> Write trx: Closing bypassed page pageKey={}, revision={}", - pathSummaryRecordPage.page.getPageKey(), pathSummaryRecordPage.page.getRevision()); + pathSummaryRecordPage.page.getPageKey(), + pathSummaryRecordPage.page.getRevision()); } pathSummaryRecordPage.page.close(); } } } - pathSummaryRecordPage = new RecordPage(indexLogKey.getIndexNumber(), indexLogKey.getIndexType(), - indexLogKey.getRecordPageKey(), indexLogKey.getRevisionNumber(), pageReference, recordPage); + pathSummaryRecordPage = new RecordPage(indexLogKey.getIndexNumber(), + indexLogKey.getIndexType(), + indexLogKey.getRecordPageKey(), + indexLogKey.getRevisionNumber(), + pageReference, + recordPage); } else { // Set as most recent page for this type/index (auto-unpins previous) - var newRecordPage = new RecordPage(indexLogKey.getIndexNumber(), indexLogKey.getIndexType(), - indexLogKey.getRecordPageKey(), indexLogKey.getRevisionNumber(), pageReference, recordPage); + var newRecordPage = new RecordPage(indexLogKey.getIndexNumber(), + indexLogKey.getIndexType(), + indexLogKey.getRecordPageKey(), + indexLogKey.getRevisionNumber(), + pageReference, + recordPage); setMostRecentPage(indexLogKey.getIndexType(), indexLogKey.getIndexNumber(), newRecordPage); } } @@ -1145,9 +1167,9 @@ private void setMostRecentlyReadRecordPage(@NonNull IndexLogKey indexLogKey, @No /** * Load a page from storage and combine with historical fragments for versioning. *

- * This method handles the versioning reconstruction by loading the current page fragment and - * combining it with previous revisions according to the configured versioning strategy (e.g., - * incremental, differential, full). + * This method handles the versioning reconstruction by loading the current page + * fragment and combining it with previous revisions according to the configured + * versioning strategy (e.g., incremental, differential, full). * * @param pageReferenceToRecordPage reference to the page to load * @return the combined page, or null if no page exists at this reference @@ -1201,8 +1223,9 @@ private Page getInMemoryPageInstance(@NonNull IndexLogKey indexLogKey, if (trxIntentLog == null || indexLogKey.getIndexType() != IndexType.PATH_SUMMARY) { var kvLeafPage = ((KeyValueLeafPage) page); if (DEBUG_PATH_SUMMARY && indexLogKey.getIndexType() == IndexType.PATH_SUMMARY) { - LOGGER.debug("[PATH_SUMMARY-SWIZZLED] Found swizzled page: pageKey={}, revision={}", kvLeafPage.getPageKey(), - kvLeafPage.getRevision()); + LOGGER.debug("[PATH_SUMMARY-SWIZZLED] Found swizzled page: pageKey={}, revision={}", + kvLeafPage.getPageKey(), + kvLeafPage.getRevision()); } // Fast path: Use swizzled page directly if still valid @@ -1210,15 +1233,15 @@ private Page getInMemoryPageInstance(@NonNull IndexLogKey indexLogKey, // This prevents TOCTOU race where page is closed between check and guard acquisition closeCurrentPageGuard(); kvLeafPage.acquireGuard(); - + // Now check if page is still valid (not closed, memory not released) - if (!kvLeafPage.isClosed() && kvLeafPage.getSlotMemory() != null) { + if (!kvLeafPage.isClosed() && kvLeafPage.getSlottedPage() != null) { currentPageGuard = PageGuard.wrapAlreadyGuarded(kvLeafPage); } else { // Swizzled page was closed - release guard and reload kvLeafPage.releaseGuard(); - pageReferenceToRecordPage.setPage(null); // Clear stale swizzled reference - return null; // Signal caller to reload + pageReferenceToRecordPage.setPage(null); // Clear stale swizzled reference + return null; // Signal caller to reload } } return page; @@ -1240,19 +1263,18 @@ PageReference getLeafPageReference(final PageReference pageReferenceToSubtree, f } /** - * Result of loading page fragments, including pages, original fragment keys, and storage key for - * pages[0]. + * Result of loading page fragments, including pages, original fragment keys, and storage key for pages[0]. */ record PageFragmentsResult(List> pages, List originalKeys, - long storageKeyForFirstFragment) { + long storageKeyForFirstFragment) { } /** * Dereference key/value page reference and get all page fragments from revision-trees. *

- * For versioning systems (incremental, differential), a complete page may be composed of multiple - * fragments from different revisions. This method loads all required fragments and returns them in - * order for combining. + * For versioning systems (incremental, differential), a complete page may be composed + * of multiple fragments from different revisions. This method loads all required + * fragments and returns them in order for combining. * * @param pageReference reference pointing to the first (most recent) page fragment * @return result containing all page fragments and their original keys @@ -1265,23 +1287,31 @@ PageFragmentsResult getPageFragments(final PageReference pageReference) { // FULL versioning fast path: Page IS complete - use RecordPageCache directly // This bypasses the fragment cache since there are no fragments to combine if (config.versioningType == VersioningType.FULL) { - final var pageReferenceWithKey = - new PageReference().setKey(pageReference.getKey()).setDatabaseId(databaseId).setResourceId(resourceId); + final var pageReferenceWithKey = new PageReference() + .setKey(pageReference.getKey()) + .setDatabaseId(databaseId) + .setResourceId(resourceId); // Copy hash for checksum verification if (pageReference.getHash() != null) { pageReferenceWithKey.setHash(pageReference.getHash()); } KeyValueLeafPage page = resourceBufferManager.getRecordPageCache() - .getOrLoadAndGuard(pageReferenceWithKey, - key -> (KeyValueLeafPage) pageReader.read(key, config)); + .getOrLoadAndGuard(pageReferenceWithKey, + key -> (KeyValueLeafPage) pageReader.read(key, config)); if (page != null && !page.isClosed()) { - return new PageFragmentsResult(java.util.Collections.singletonList(page), java.util.Collections.emptyList(), - pageReference.getKey()); + return new PageFragmentsResult( + java.util.Collections.singletonList(page), + java.util.Collections.emptyList(), + pageReference.getKey() + ); } - return new PageFragmentsResult(java.util.Collections.emptyList(), java.util.Collections.emptyList(), - pageReference.getKey()); + return new PageFragmentsResult( + java.util.Collections.emptyList(), + java.util.Collections.emptyList(), + pageReference.getKey() + ); } // Other versioning types: load fragments from RecordPageFragmentCache @@ -1300,10 +1330,9 @@ PageFragmentsResult getPageFragments(final PageReference pageReference) { } // Load first fragment atomically with guard - KeyValueLeafPage page = - resourceBufferManager.getRecordPageFragmentCache() - .getOrLoadAndGuard(pageReferenceWithKey, - key -> (KeyValueLeafPage) pageReader.read(key, resourceSession.getResourceConfig())); + KeyValueLeafPage page = resourceBufferManager.getRecordPageFragmentCache() + .getOrLoadAndGuard(pageReferenceWithKey, + key -> (KeyValueLeafPage) pageReader.read(key, resourceSession.getResourceConfig())); assert page != null && !page.isClosed(); pages.add(page); @@ -1338,28 +1367,27 @@ private CompletableFuture> readPage(final PageFragmentK KeyValueLeafPage pageFromCache = resourceBufferManager.getRecordPageFragmentCache().getAndGuard(pageReference); if (pageFromCache != null) { - assert pageFragmentKey.revision() == pageFromCache.getRevision() - : "Revision mismatch: key=" + pageFragmentKey.revision() + ", page=" + pageFromCache.getRevision(); + assert pageFragmentKey.revision() == pageFromCache.getRevision() : + "Revision mismatch: key=" + pageFragmentKey.revision() + ", page=" + pageFromCache.getRevision(); return CompletableFuture.completedFuture(pageFromCache); } // Cache miss - load async, then cache with atomic guard acquisition final var reader = resourceSession.createReader(); - return reader.readAsync(pageReference, resourceSession.getResourceConfig()).thenApply(loadedPage -> { - reader.close(); - assert pageFragmentKey.revision() == ((KeyValuePage) loadedPage).getRevision() - : "Revision mismatch: key=" + pageFragmentKey.revision() + ", page=" - + ((KeyValuePage) loadedPage).getRevision(); - - // Atomic cache-or-store with guard (handles race with other threads) - // If another thread cached the page first, returns that cached page with guard. - // Otherwise caches our loaded page with guard. - KeyValueLeafPage cachedPage = - resourceBufferManager.getRecordPageFragmentCache() - .getOrLoadAndGuard(pageReference, _ -> (KeyValueLeafPage) loadedPage); - - return (KeyValuePage) cachedPage; - }); + return reader.readAsync(pageReference, resourceSession.getResourceConfig()) + .thenApply(loadedPage -> { + reader.close(); + assert pageFragmentKey.revision() == ((KeyValuePage) loadedPage).getRevision() : + "Revision mismatch: key=" + pageFragmentKey.revision() + ", page=" + ((KeyValuePage) loadedPage).getRevision(); + + // Atomic cache-or-store with guard (handles race with other threads) + // If another thread cached the page first, returns that cached page with guard. + // Otherwise caches our loaded page with guard. + KeyValueLeafPage cachedPage = resourceBufferManager.getRecordPageFragmentCache() + .getOrLoadAndGuard(pageReference, _ -> (KeyValueLeafPage) loadedPage); + + return (KeyValuePage) cachedPage; + }); } static CompletableFuture> sequence(List> listOfCompletableFutures) { @@ -1374,8 +1402,8 @@ static CompletableFuture> sequence(List> listOf * nodes, Path index nodes or Name index nodes). * * @param revisionRoot {@link RevisionRootPage} instance - * @param indexType the index type - * @param index the index to use + * @param indexType the index type + * @param index the index to use */ PageReference getPageReference(final RevisionRootPage revisionRoot, final IndexType indexType, final int index) { assert revisionRoot != null; @@ -1390,7 +1418,7 @@ PageReference getPageReference(final RevisionRootPage revisionRoot, final IndexT case NAME -> getNamePage(revisionRoot).getIndirectPageReference(index); case PATH_SUMMARY -> getPathSummaryPage(revisionRoot).getIndirectPageReference(index); default -> - throw new IllegalStateException("Only defined for node, path summary, text value and attribute value pages!"); + throw new IllegalStateException("Only defined for node, path summary, text value and attribute value pages!"); }; } @@ -1399,7 +1427,7 @@ PageReference getPageReference(final RevisionRootPage revisionRoot, final IndexT * * @param reference reference to dereference * @return dereferenced page - * @throws SirixIOException if something odd happens within the creation process + * @throws SirixIOException if something odd happens within the creation process * @throws NullPointerException if {@code reference} is {@code null} */ @Override @@ -1411,7 +1439,7 @@ public IndirectPage dereferenceIndirectPageReference(final PageReference referen * Find reference pointing to leaf page of an indirect tree. * * @param startReference start reference pointing to the indirect tree - * @param pageKey key to look up in the indirect tree + * @param pageKey key to look up in the indirect tree * @return reference denoted by key pointing to the leaf page * @throws SirixIOException if an I/O error occurs */ @@ -1429,8 +1457,8 @@ public PageReference getReferenceToLeafOfSubtree(final PageReference startRefere final int maxHeight = getCurrentMaxIndirectPageTreeLevel(indexType, indexNumber, revisionRootPage); // Iterate through all levels. - for (int level = inpLevelPageCountExp.length - maxHeight, - height = inpLevelPageCountExp.length; level < height; level++) { + for (int level = inpLevelPageCountExp.length - maxHeight, height = inpLevelPageCountExp.length; + level < height; level++) { final Page derefPage = dereferenceIndirectPageReference(reference); if (derefPage == null) { reference = null; @@ -1467,9 +1495,7 @@ public long pageKey(@NonNegative final long recordKey, @NonNull final IndexType public int getCurrentMaxIndirectPageTreeLevel(final IndexType indexType, final int index, final RevisionRootPage revisionRootPage) { final int maxLevel; - final RevisionRootPage currentRevisionRootPage = revisionRootPage == null - ? rootPage - : revisionRootPage; + final RevisionRootPage currentRevisionRootPage = revisionRootPage == null ? rootPage : revisionRootPage; // $CASES-OMITTED$ maxLevel = switch (indexType) { @@ -1504,8 +1530,8 @@ public String toString() { } /** - * Close the current page guard if one is active. Should be called before fetching a different page - * or when transaction closes. + * Close the current page guard if one is active. + * Should be called before fetching a different page or when transaction closes. *

* Package-private to allow NodeStorageEngineWriter to release guards before TIL operations. */ @@ -1522,15 +1548,13 @@ void closeCurrentPageGuard() { } /** - * Get the page that the current page guard is protecting. Used by NodeStorageEngineWriter for - * acquiring additional guards on the current page. + * Get the page that the current page guard is protecting. + * Used by NodeStorageEngineWriter for acquiring additional guards on the current page. * * @return the current page, or null if no page is currently guarded */ public KeyValueLeafPage getCurrentPage() { - return currentPageGuard != null - ? currentPageGuard.page() - : null; + return currentPageGuard != null ? currentPageGuard.page() : null; } @Override @@ -1621,13 +1645,13 @@ public CommitCredentials getCommitCredentials() { @Override public @Nullable HOTLeafPage getHOTLeafPage(@NonNull IndexType indexType, int indexNumber) { assertNotClosed(); - + // CRITICAL: Use getActualRevisionRootPage() to get the current revision root, // which for write transactions is the NEW revision root page where HOT pages are stored. // Using the old 'rootPage' field would fail for write transactions because the HOT // pages are stored against the new revision's PathPage/CASPage/NamePage references. final RevisionRootPage actualRootPage = getActualRevisionRootPage(); - + // Get the root reference for the index final PageReference rootRef = switch (indexType) { case PATH -> { @@ -1653,11 +1677,11 @@ public CommitCredentials getCommitCredentials() { } default -> null; }; - + if (rootRef == null) { return null; } - + // FIRST: Check transaction log for uncommitted pages (write transactions) // This must be checked before anything else since uncommitted pages won't // be on the reference or in the buffer cache @@ -1675,23 +1699,23 @@ public CommitCredentials getCommitCredentials() { } } } - + // Check if page is swizzled (directly on reference) if (rootRef.getPage() instanceof HOTLeafPage hotLeaf) { return hotLeaf; } - + // For uncommitted pages with no log key, we're done if (rootRef.getKey() < 0 && rootRef.getLogKey() < 0) { return null; } - + // Try to get from buffer cache Page cachedPage = resourceBufferManager.getRecordPageCache().get(rootRef); if (cachedPage instanceof HOTLeafPage hotLeaf) { return hotLeaf; } - + // Load from storage with proper versioning fragment combining if (rootRef.getKey() >= 0) { try { @@ -1701,17 +1725,15 @@ public CommitCredentials getCommitCredentials() { return null; } } - + return null; } - + /** * Load a HOTLeafPage from storage with proper versioning fragment combining. * - *

- * For FULL versioning, loads a single complete page. For INCREMENTAL/DIFFERENTIAL/SLIDING_SNAPSHOT, - * loads all fragments and combines them. - *

+ *

For FULL versioning, loads a single complete page. + * For INCREMENTAL/DIFFERENTIAL/SLIDING_SNAPSHOT, loads all fragments and combines them.

* * @param pageRef the page reference * @return the combined HOTLeafPage, or null if not found @@ -1719,29 +1741,29 @@ public CommitCredentials getCommitCredentials() { private @Nullable HOTLeafPage loadHOTLeafPageWithVersioning(PageReference pageRef) { final VersioningType versioningType = resourceConfig.versioningType; final int revsToRestore = resourceConfig.maxNumberOfRevisionsToRestore; - + // FULL versioning fast path: Page on disk IS complete - load directly if (versioningType == VersioningType.FULL) { Page loadedPage = pageReader.read(pageRef, resourceConfig); - if (loadedPage instanceof HOTLeafPage hotLeaf) { + if (loadedPage instanceof HOTLeafPage hotLeaf) { pageRef.setPage(hotLeaf); - return hotLeaf; + return hotLeaf; } return null; } - + // Other versioning types: load fragments and combine List fragments = loadHOTPageFragments(pageRef); if (fragments.isEmpty()) { return null; } - + // Combine fragments using VersioningType HOTLeafPage combinedPage = versioningType.combineHOTLeafPages(fragments, revsToRestore, this); pageRef.setPage(combinedPage); return combinedPage; } - + /** * Load all HOTLeafPage fragments for versioning reconstruction. * @@ -1750,44 +1772,46 @@ public CommitCredentials getCommitCredentials() { */ private List loadHOTPageFragments(PageReference pageRef) { final List fragments = new ArrayList<>(); - + // Load the first (most recent) fragment Page firstPage = pageReader.read(pageRef, resourceConfig); if (!(firstPage instanceof HOTLeafPage hotLeaf)) { return fragments; } fragments.add(hotLeaf); - + // Check if this is already a complete page (for FULL versioning) or no fragments List pageFragments = pageRef.getPageFragments(); if (pageFragments.isEmpty()) { return fragments; } - + // Load additional fragments from the versioning chain // Note: Fragment keys don't include hashes - only the first fragment can be verified // Future improvement: Store fragment hashes in PageFragmentKey for complete verification for (PageFragmentKey fragmentKey : pageFragments) { - PageReference fragmentRef = - new PageReference().setKey(fragmentKey.key()).setDatabaseId(databaseId).setResourceId(resourceId); - + PageReference fragmentRef = new PageReference() + .setKey(fragmentKey.key()) + .setDatabaseId(databaseId) + .setResourceId(resourceId); + Page fragmentPage = pageReader.read(fragmentRef, resourceConfig); if (fragmentPage instanceof HOTLeafPage hotFragment) { fragments.add(hotFragment); } } - + return fragments; } - + @Override public @Nullable Page loadHOTPage(@NonNull PageReference reference) { assertNotClosed(); - + if (reference == null) { return null; } - + // FIRST: Check transaction log for uncommitted pages (write transactions) if (trxIntentLog != null) { final PageContainer container = trxIntentLog.get(reference); @@ -1803,24 +1827,24 @@ private List loadHOTPageFragments(PageReference pageRef) { } } } - + // Check if page is swizzled (directly on reference) Page swizzled = reference.getPage(); if (swizzled instanceof HOTLeafPage || swizzled instanceof HOTIndirectPage) { return swizzled; } - + // For uncommitted pages with no log key, we're done if (reference.getKey() < 0 && reference.getLogKey() < 0) { return null; } - + // Try to get from buffer cache Page cachedPage = resourceBufferManager.getRecordPageCache().get(reference); if (cachedPage instanceof HOTLeafPage || cachedPage instanceof HOTIndirectPage) { return cachedPage; } - + // Load from storage (only if key >= 0) if (reference.getKey() >= 0) { try { @@ -1832,7 +1856,7 @@ private List loadHOTPageFragments(PageReference pageRef) { reference.setPage(loadedPage); return loadedPage; } - + if (loadedPage instanceof HOTLeafPage) { // HOTLeafPage needs proper versioning fragment combining HOTLeafPage combinedPage = loadHOTLeafPageWithVersioning(reference); @@ -1843,7 +1867,7 @@ private List loadHOTPageFragments(PageReference pageRef) { return null; } } - + return null; } } diff --git a/bundles/sirix-core/src/main/java/io/sirix/access/trx/page/NodeStorageEngineWriter.java b/bundles/sirix-core/src/main/java/io/sirix/access/trx/page/NodeStorageEngineWriter.java index c70cff98d..0807d930c 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/access/trx/page/NodeStorageEngineWriter.java +++ b/bundles/sirix-core/src/main/java/io/sirix/access/trx/page/NodeStorageEngineWriter.java @@ -21,7 +21,6 @@ package io.sirix.access.trx.page; -import io.brackit.query.atomic.QNm; import io.sirix.access.ResourceConfiguration; import io.sirix.access.User; import io.sirix.access.trx.node.CommitCredentials; @@ -39,48 +38,24 @@ import io.sirix.exception.SirixIOException; import io.sirix.io.SerializationBufferPool; import io.sirix.node.PooledBytesOut; -import io.sirix.node.MemorySegmentBytesIn; -import io.sirix.node.MemorySegmentBytesOut; import io.sirix.utils.OS; import io.sirix.index.IndexType; import io.sirix.io.Writer; import io.sirix.node.DeletedNode; import io.sirix.node.NodeKind; import io.sirix.node.SirixDeweyID; -import io.sirix.node.json.ArrayNode; -import io.sirix.node.json.BooleanNode; -import io.sirix.node.json.JsonDocumentRootNode; -import io.sirix.node.json.NullNode; -import io.sirix.node.json.NumberNode; -import io.sirix.node.json.ObjectBooleanNode; -import io.sirix.node.json.ObjectKeyNode; -import io.sirix.node.json.ObjectNode; -import io.sirix.node.json.ObjectNullNode; -import io.sirix.node.json.ObjectNumberNode; -import io.sirix.node.json.ObjectStringNode; -import io.sirix.node.json.StringNode; -import io.sirix.node.xml.AttributeNode; -import io.sirix.node.xml.CommentNode; -import io.sirix.node.xml.NamespaceNode; -import io.sirix.node.xml.PINode; -import io.sirix.node.xml.TextNode; -import io.sirix.node.xml.ElementNode; -import io.sirix.node.xml.XmlDocumentRootNode; -import io.sirix.node.layout.FixedSlotRecordMaterializer; -import io.sirix.node.layout.FixedSlotRecordProjector; -import io.sirix.node.layout.NodeKindLayout; import io.sirix.node.delegates.NodeDelegate; import io.sirix.node.interfaces.DataRecord; +import io.sirix.node.interfaces.FlyweightNode; import io.sirix.node.interfaces.Node; -import io.sirix.node.interfaces.ReusableNodeProxy; import io.sirix.page.CASPage; import io.sirix.page.DeweyIDPage; import io.sirix.page.HOTIndirectPage; import io.sirix.page.HOTLeafPage; import io.sirix.page.IndirectPage; import io.sirix.page.KeyValueLeafPage; +import io.sirix.page.PageLayout; import io.sirix.page.NamePage; -import io.sirix.page.PageConstants; import io.sirix.page.PageKind; import io.sirix.page.PageReference; import io.sirix.page.PathPage; @@ -91,7 +66,6 @@ import io.sirix.page.interfaces.KeyValuePage; import io.sirix.page.interfaces.Page; import io.sirix.settings.Constants; -import io.sirix.settings.DiagnosticSettings; import io.sirix.settings.Fixed; import io.sirix.settings.VersioningType; import io.sirix.node.BytesOut; @@ -102,9 +76,9 @@ import org.slf4j.Logger; import org.slf4j.LoggerFactory; +import java.lang.foreign.MemorySegment; import java.io.IOException; import java.io.OutputStream; -import java.lang.foreign.MemorySegment; import java.nio.file.Files; import java.nio.file.Path; import java.time.Instant; @@ -134,17 +108,7 @@ final class NodeStorageEngineWriter extends AbstractForwardingStorageEngineReade private static final Logger LOGGER = LoggerFactory.getLogger(NodeStorageEngineWriter.class); - /** - * Debug flag for memory leak tracking. - * - * @see DiagnosticSettings#MEMORY_LEAK_TRACKING - */ - private static final boolean DEBUG_MEMORY_LEAKS = DiagnosticSettings.MEMORY_LEAK_TRACKING; - private BytesOut bufferBytes = Bytes.elasticOffHeapByteBuffer(Writer.FLUSH_SIZE); - private MemorySegmentBytesOut demotionBuffer; - private MemorySegment fixedSlotProjectionBuffer; - /** * Page writer to serialize. @@ -232,29 +196,14 @@ private record IndexLogKeyToPageContainer(IndexType indexType, long recordPageKe */ private IndexLogKeyToPageContainer mostRecentPathSummaryPageContainer; - // Write-path singletons — one per XML/JSON node kind (lazily allocated) - private ObjectNode writeObjectSingleton; - private ArrayNode writeArraySingleton; - private ObjectKeyNode writeObjectKeySingleton; - private StringNode writeStringSingleton; - private NumberNode writeNumberSingleton; - private BooleanNode writeBooleanSingleton; - private NullNode writeNullSingleton; - private ObjectStringNode writeObjectStringSingleton; - private ObjectNumberNode writeObjectNumberSingleton; - private ObjectBooleanNode writeObjectBooleanSingleton; - private ObjectNullNode writeObjectNullSingleton; - private JsonDocumentRootNode writeJsonDocumentSingleton; - private XmlDocumentRootNode writeXmlDocumentSingleton; - private ElementNode writeElementSingleton; - private TextNode writeTextSingleton; - private CommentNode writeCommentSingleton; - private AttributeNode writeAttributeSingleton; - private NamespaceNode writeNamespaceSingleton; - private PINode writePISingleton; - private final LinkedHashMap pageContainerCache; + /** + * Optional binder for write-path singletons. + * When set, prepareRecordForModification uses factory singletons instead of allocating new nodes. + */ + private WriteSingletonBinder writeSingletonBinder; + /** * Constructor. * @@ -343,6 +292,11 @@ public HOTTrieWriter getHOTTrieWriter() { return hotTrieWriter; } + @Override + public void setWriteSingletonBinder(final WriteSingletonBinder binder) { + this.writeSingletonBinder = binder; + } + @Override public BytesOut newBufferedBytesInstance() { bufferBytes = Bytes.elasticOffHeapByteBuffer(Writer.FLUSH_SIZE); @@ -385,31 +339,18 @@ public DataRecord prepareRecordForModification(final long recordKey, @NonNull fi return record; } - // Try fixed-slot singleton path — zero allocation hot path. - // The write singleton is populated from fixed-slot bytes (authoritative state). - // Callers must use the returned object immediately, mutate, and persist via - // updateRecordSlot before the next prepareRecordForModification call for the - // same node kind (use-persist-discard rule). - if (modifiedPage instanceof KeyValueLeafPage modifiedLeafPage && modifiedLeafPage.isFixedSlotFormat(recordOffset)) { - final NodeKind nodeKind = modifiedLeafPage.getFixedSlotNodeKind(recordOffset); - if (nodeKind != null) { - final long dataOffset = modifiedLeafPage.getSlotDataOffset(recordOffset); - if (dataOffset >= 0) { - final DataRecord singleton = getOrCreateWriteSingleton(nodeKind); - if (singleton != null) { - final int dataLength = modifiedLeafPage.getSlotDataLength(recordOffset); - final byte[] deweyIdBytes = modifiedLeafPage.getDeweyIdAsByteArray(recordOffset); - if (FixedSlotRecordMaterializer.populateExisting(singleton, nodeKind, recordKey, - modifiedLeafPage.getSlotMemory(), dataOffset, dataLength, deweyIdBytes, - storageEngineReader.getResourceSession().getResourceConfig())) { - return singleton; // Zero-allocation hot path - } - } - } + // Zero-allocation fast path: bind write singleton to modified page's slotted page. + // Write singletons are NOT stored in records[], so this path is hit on every access + // to a previously created/modified record. The bind is cheap (4 field assignments). + if (writeSingletonBinder != null && modifiedPage instanceof KeyValueLeafPage kvl + && kvl.hasSlottedPageSlot(recordKey)) { + record = writeSingletonBinder.bind(kvl, recordOffset, recordKey); + if (record != null) { + return record; } } - // Try compact-format / records[] on the modified page. + // Try deserialization from modified page's slotted page (non-singleton path). record = storageEngineReader.getValue(modifiedPage, recordKey); if (record != null) { modifiedPage.setRecord(record); @@ -417,132 +358,81 @@ record = storageEngineReader.getValue(modifiedPage, recordKey); } // Fall back to complete (on-disk) page. - final DataRecord oldRecord = storageEngineReader.getValue(cont.getCompleteAsKeyValuePage(), recordKey); + final var completePage = cont.getCompleteAsKeyValuePage(); + + // Zero-copy path: copy raw slot bytes from complete page to modified page, then bind. + if (writeSingletonBinder != null && modifiedPage instanceof KeyValueLeafPage kvlMod + && completePage instanceof KeyValueLeafPage kvlComplete) { + final MemorySegment srcPage = kvlComplete.getSlottedPage(); + if (srcPage != null && PageLayout.isSlotPopulated(srcPage, recordOffset) + && PageLayout.getDirNodeKindId(srcPage, recordOffset) > 0) { + kvlMod.copySlotFromPage(kvlComplete, recordOffset); + record = writeSingletonBinder.bind(kvlMod, recordOffset, recordKey); + if (record != null) { + return record; + } + } + } + + // Fallback for non-binder, binder returned null, or non-FlyweightNode (nodeKindId=0) + final DataRecord oldRecord = storageEngineReader.getValue(completePage, recordKey); if (oldRecord == null) { + final int offset = StorageEngineReader.recordPageOffset(recordKey); + final var kvlComplete = (KeyValueLeafPage) completePage; + final var slottedPage = kvlComplete.getSlottedPage(); + final boolean slotPopulated = slottedPage != null + && PageLayout.isSlotPopulated(slottedPage, offset); + final var slotData = completePage.getSlot(offset); + final int populatedCount = slottedPage != null + ? PageLayout.getPopulatedCount(slottedPage) : -1; throw new SirixIOException("Cannot retrieve record from cache: (key: " + recordKey + ") (indexType: " + indexType - + ") (index: " + index + ")"); + + ") (index: " + index + ") (slotPopulated: " + slotPopulated + + ") (populatedCount: " + populatedCount + + ") (slotData: " + (slotData != null ? slotData.byteSize() + " bytes" : "null") + + ") (completePage.pageKey: " + completePage.getPageKey() + + ") (completePage.revision: " + completePage.getRevision() + + ") (modifiedPage.pageKey: " + modifiedPage.getPageKey() + ")"); } record = oldRecord; - // Project disk-read records to fixed-slot format if eligible. - // Fixed-slot bytes are now authoritative. Don't cache in records[] — - // next access will use write singleton via fixed-slot path. - if (modifiedPage instanceof KeyValueLeafPage modifiedLeafPage && indexType == IndexType.DOCUMENT) { - final ResourceConfiguration resourceConfiguration = storageEngineReader.getResourceSession().getResourceConfig(); - if (tryProjectRecordIntoFixedSlot(record, modifiedLeafPage, resourceConfiguration)) { - return record; - } + // Unbind flyweight from complete page — ensures mutations go to Java fields, + // not the old revision's MemorySegment. setRecord will re-serialize to modified page. + if (record instanceof FlyweightNode fn && fn.isBound()) { + fn.unbind(); } - // Non-fixed-slot: cache in records[] for stable reference identity. + modifiedPage.setRecord(record); return record; } - @Override - public void updateRecordSlot(@NonNull final DataRecord record, @NonNull final IndexType indexType, final int index) { - storageEngineReader.assertNotClosed(); - requireNonNull(record); - requireNonNull(indexType); - checkArgument(record.getNodeKey() >= 0, "recordKey must be >= 0!"); - - final long recordKey = record.getNodeKey(); - final long recordPageKey = storageEngineReader.pageKey(recordKey, indexType); - final PageContainer container = prepareRecordPage(recordPageKey, index, indexType); - final KeyValuePage modifiedPage = container.getModifiedAsKeyValuePage(); - - if (!(modifiedPage instanceof KeyValueLeafPage modifiedLeafPage)) { - modifiedPage.setRecord(record); - return; - } + // ==================== DIRECT-TO-HEAP CREATION ==================== - final ResourceConfiguration resourceConfiguration = storageEngineReader.getResourceSession().getResourceConfig(); - if (tryProjectRecordIntoFixedSlot(record, modifiedLeafPage, resourceConfiguration)) { - // Fixed-slot projection succeeded — fixed-slot bytes are the authoritative - // in-memory representation. No records[] entry needed; compactFixedSlotsForCommit - // handles serialization at commit time. - return; - } + /** Reusable allocation result — zero-alloc on hot path. */ + private KeyValueLeafPage allocKvl; + private int allocSlotOffset; + private long allocNodeKey; - // Non-fixed-slot records (payload-bearing kinds like StringNode/NumberNode): - // store in records[] for commit-time serialization via processEntries(). - modifiedPage.setRecord(record); + @Override + public void allocateForDocumentCreation() { + storageEngineReader.assertNotClosed(); + final long nodeKey = newRevisionRootPage.incrementAndGetMaxNodeKeyInDocumentIndex(); + final long recordPageKey = storageEngineReader.pageKey(nodeKey, IndexType.DOCUMENT); + final PageContainer cont = prepareRecordPage(recordPageKey, -1, IndexType.DOCUMENT); + this.allocKvl = (KeyValueLeafPage) cont.getModifiedAsKeyValuePage(); + this.allocSlotOffset = (int) (nodeKey + - ((nodeKey >> Constants.NDP_NODE_COUNT_EXPONENT) << Constants.NDP_NODE_COUNT_EXPONENT)); + this.allocNodeKey = nodeKey; } - private boolean tryProjectRecordIntoFixedSlot(final DataRecord record, final KeyValueLeafPage modifiedLeafPage, - final ResourceConfiguration resourceConfiguration) { - if (!(record.getKind() instanceof NodeKind nodeKind)) { - return false; - } - - final NodeKindLayout layout = nodeKind.layoutDescriptor(); - if (!layout.isFixedSlotSupported()) { - return false; - } - - // Only VALUE_BLOB payload refs are supported for inline projection. - if (!layout.hasSupportedPayloads()) { - return false; - } - - final int fixedSlotSize = layout.fixedSlotSizeInBytes(); - if (fixedSlotSize <= 0) { - return false; - } - - // Compute inline payload length for payload-bearing nodes (strings, numbers). - final int inlinePayloadLength = FixedSlotRecordProjector.computeInlinePayloadLength(record, layout); - if (inlinePayloadLength < 0) { - return false; - } - - final int totalSlotSize = fixedSlotSize + inlinePayloadLength; - if (totalSlotSize > PageConstants.MAX_RECORD_SIZE) { - return false; - } - - final int recordOffset = StorageEngineReader.recordPageOffset(record.getNodeKey()); - long dataOffset = modifiedLeafPage.getSlotDataOffset(recordOffset); - int dataLength = (dataOffset >= 0) - ? modifiedLeafPage.getSlotDataLength(recordOffset) - : -1; - if (dataOffset < 0 || dataLength != totalSlotSize) { - final MemorySegment projectionBuffer = ensureFixedSlotProjectionBuffer(totalSlotSize); - modifiedLeafPage.setSlot(projectionBuffer.asSlice(0, totalSlotSize), recordOffset); - dataOffset = modifiedLeafPage.getSlotDataOffset(recordOffset); - dataLength = (dataOffset >= 0) - ? modifiedLeafPage.getSlotDataLength(recordOffset) - : -1; - if (dataOffset < 0 || dataLength != totalSlotSize) { - return false; - } - } - - if (!FixedSlotRecordProjector.project(record, layout, modifiedLeafPage.getSlotMemory(), dataOffset)) { - return false; - } - modifiedLeafPage.markSlotAsFixedFormat(recordOffset, nodeKind); - - if (resourceConfiguration.areDeweyIDsStored) { - final byte[] deweyId = record.getDeweyIDAsBytes(); - if (deweyId != null && deweyId.length > 0) { - modifiedLeafPage.setDeweyId(deweyId, recordOffset); - } - } + @Override + public KeyValueLeafPage getAllocKvl() { return allocKvl; } - return true; - } + @Override + public int getAllocSlotOffset() { return allocSlotOffset; } - private MemorySegment ensureFixedSlotProjectionBuffer(final int requiredSize) { - if (fixedSlotProjectionBuffer == null || fixedSlotProjectionBuffer.byteSize() < requiredSize) { - int newSize = 256; - while (newSize < requiredSize) { - newSize <<= 1; - } - fixedSlotProjectionBuffer = MemorySegment.ofArray(new byte[newSize]); - } - return fixedSlotProjectionBuffer; - } + @Override + public long getAllocNodeKey() { return allocNodeKey; } @Override public DataRecord createRecord(@NonNull final DataRecord record, @NonNull final IndexType indexType, @@ -595,69 +485,35 @@ public DataRecord createRecord(@NonNull final DataRecord record, @NonNull final final long recordPageKey = storageEngineReader.pageKey(createdRecordKey, indexType); final PageContainer cont = prepareRecordPage(recordPageKey, index, indexType); final KeyValuePage modified = cont.getModifiedAsKeyValuePage(); - final boolean storedAsReusableProxy = - persistReusableProxyRecordIfSupported(record, createdRecordKey, indexType, modified); - if (!storedAsReusableProxy) { - modified.setRecord(record); - if (modified instanceof KeyValueLeafPage modifiedLeafPage && modifiedLeafPage.shouldDemoteRecords(indexType)) { - if (demotionBuffer == null) { - demotionBuffer = new MemorySegmentBytesOut(256); - } - modifiedLeafPage.demoteRecordsToSlots(storageEngineReader.getResourceSession().getResourceConfig(), demotionBuffer); + if (modified instanceof KeyValueLeafPage kvl) { + if (record instanceof FlyweightNode fn) { + final int offset = (int) (createdRecordKey + - ((createdRecordKey >> Constants.NDP_NODE_COUNT_EXPONENT) + << Constants.NDP_NODE_COUNT_EXPONENT)); + kvl.serializeNewRecord(fn, createdRecordKey, offset); + } else { + kvl.setNewRecord(record); } + } else { + modified.setRecord(record); } return record; } - private boolean persistReusableProxyRecordIfSupported(final DataRecord record, final long createdRecordKey, - @NonNull final IndexType indexType, final KeyValuePage modified) { - if (indexType != IndexType.DOCUMENT || !(record instanceof ReusableNodeProxy) - || !(modified instanceof KeyValueLeafPage modifiedLeafPage) || record.getNodeKey() != createdRecordKey) { - return false; - } - - if (demotionBuffer == null) { - demotionBuffer = new MemorySegmentBytesOut(256); - } - demotionBuffer.clear(); - - final ResourceConfiguration resourceConfiguration = storageEngineReader.getResourceSession().getResourceConfig(); - if (tryProjectRecordIntoFixedSlot(record, modifiedLeafPage, resourceConfiguration)) { - return true; - } - - resourceConfiguration.recordPersister.serialize(demotionBuffer, record, resourceConfiguration); - final var serializedRecord = demotionBuffer.getDestination(); - - if (serializedRecord.byteSize() > PageConstants.MAX_RECORD_SIZE) { - final DataRecord detachedRecord = materializeDetachedRecord(serializedRecord, record, resourceConfiguration); - modified.setRecord(detachedRecord); - if (modifiedLeafPage.shouldDemoteRecords(indexType)) { - modifiedLeafPage.demoteRecordsToSlots(resourceConfiguration, demotionBuffer); - } - return true; - } - - final int recordOffset = StorageEngineReader.recordPageOffset(record.getNodeKey()); - modifiedLeafPage.setSlot(serializedRecord, recordOffset); - modifiedLeafPage.markSlotAsCompactFormat(recordOffset); - - if (resourceConfiguration.areDeweyIDsStored) { - final byte[] deweyId = record.getDeweyIDAsBytes(); - if (deweyId != null && deweyId.length > 0) { - modifiedLeafPage.setDeweyId(deweyId, recordOffset); - } + @Override + public void persistRecord(@NonNull final DataRecord record, @NonNull final IndexType indexType, final int index) { + if (record instanceof FlyweightNode fn && fn.isWriteSingleton() && fn.getOwnerPage() != null) { + return; // Bound write singleton — mutations already on heap } + storageEngineReader.assertNotClosed(); + requireNonNull(record); + requireNonNull(indexType); - return true; - } - - private DataRecord materializeDetachedRecord(final java.lang.foreign.MemorySegment serializedRecord, - final DataRecord sourceRecord, final ResourceConfiguration resourceConfiguration) { - return resourceConfiguration.recordPersister.deserialize(new MemorySegmentBytesIn(serializedRecord), - sourceRecord.getNodeKey(), sourceRecord.getDeweyIDAsBytes(), resourceConfiguration); + final long recordPageKey = storageEngineReader.pageKey(record.getNodeKey(), indexType); + final PageContainer cont = prepareRecordPage(recordPageKey, index, indexType); + cont.getModifiedAsKeyValuePage().setRecord(record); } @Override @@ -691,7 +547,17 @@ public V getRecord(final long recordKey, @NonNull final I final PageContainer pageCont = getPageContainer(recordPageKey, index, indexType); if (pageCont == null) { - return storageEngineReader.getRecord(recordKey, indexType, index); + // Fallback to underlying reader. The reader may return a FlyweightNode bound to a page + // whose MemorySegment lifecycle is managed by the reader (guard-based eviction). + // Since the writer cannot hold the reader's page guard, the segment may be freed and + // reused at any time (e.g., by the clock sweeper between successive reader calls). + // Unbinding materializes all fields to Java primitives, making the node independent + // of the page segment and preventing use-after-free. + final V record = storageEngineReader.getRecord(recordKey, indexType, index); + if (record instanceof FlyweightNode fn && fn.isBound()) { + fn.unbind(); + } + return record; } else { DataRecord node = getRecordForWriteAccess(((KeyValueLeafPage) pageCont.getModified()), recordKey); if (node == null) { @@ -709,29 +575,6 @@ private DataRecord getRecordForWriteAccess(final KeyValuePage 0 check) storageEngineReader.closeCurrentPageGuard(); - if (DEBUG_MEMORY_LEAKS) { - LOGGER.debug("[WRITER-COMMIT] Clearing TIL with {} entries before commit", log.size()); - } - // Clear TransactionIntentLog - closes all modified pages log.clear(); @@ -980,10 +809,6 @@ private void setUserIfPresent() { public UberPage rollback() { storageEngineReader.assertNotClosed(); - if (DEBUG_MEMORY_LEAKS) { - LOGGER.debug("[WRITER-ROLLBACK] Rolling back transaction with {} TIL entries", log.size()); - } - // CRITICAL: Release current page guard BEFORE TIL.clear() // If guard is on a TIL page, the page won't close (guardCount > 0 check) storageEngineReader.closeCurrentPageGuard(); @@ -1016,12 +841,6 @@ public void close() { pendingFsync = null; } - // Release the demotion buffer's off-heap memory. - if (demotionBuffer != null) { - demotionBuffer.close(); - demotionBuffer = null; - } - // Don't clear the cached containers here - they've either been: // 1. Already cleared and returned to pool during commit(), or // 2. Will be cleared and returned to pool by log.close() below @@ -1230,11 +1049,6 @@ private PageContainer prepareRecordPageViaKeyedTrie(final @NonNegative long reco false // Memory from allocator - release on close() ); - if (DEBUG_MEMORY_LEAKS && recordPageKey == 0) { - LOGGER.debug("[WRITER-CREATE] Created Page 0 pair: indexType={}, rev={}, complete={}, modify={}", indexType, - storageEngineReader.getRevisionNumber(), System.identityHashCode(completePage), System.identityHashCode(modifyPage)); - } - pageContainer = PageContainer.getInstance(completePage, modifyPage); appendLogRecord(reference, pageContainer); return pageContainer; @@ -1480,6 +1294,19 @@ public StorageEngineReader getStorageEngineReader() { return storageEngineReader; } + @Override + public KeyValueLeafPage getModifiedPageForRead(final long recordPageKey, + @NonNull final IndexType indexType, final int index) { + final PageContainer pc = getPageContainer(recordPageKey, index, indexType); + if (pc != null) { + final var modified = pc.getModified(); + if (modified instanceof KeyValueLeafPage kvl && !kvl.isClosed()) { + return kvl; + } + } + return null; + } + @Override public StorageEngineWriter appendLogRecord(@NonNull final PageReference reference, @NonNull final PageContainer pageContainer) { @@ -1513,10 +1340,9 @@ public CommitCredentials getCommitCredentials() { @Override @SuppressWarnings("deprecation") protected void finalize() { - // DIAGNOSTIC: Detect if NodeStorageEngineWriter is GC'd without being closed - if (!isClosed && KeyValueLeafPage.DEBUG_MEMORY_LEAKS) { + if (!isClosed) { LOGGER.warn( - "⚠️ NodeStorageEngineWriter FINALIZED WITHOUT CLOSE: trxId={} instance={} TIL={} with {} containers in TIL", + "NodeStorageEngineWriter FINALIZED WITHOUT CLOSE: trxId={} instance={} TIL={} with {} containers in TIL", storageEngineReader.getTrxId(), System.identityHashCode(this), System.identityHashCode(log), log.getList().size()); } } @@ -1538,137 +1364,6 @@ public PageGuard acquireGuardForCurrentNode() { return new PageGuard(currentPage); } - private static final QNm EMPTY_QNM = new QNm(""); - - /** - * Get or lazily create a write-path singleton for the given node kind. Returns null for unsupported - * kinds (non-XML/JSON). - */ - private DataRecord getOrCreateWriteSingleton(final NodeKind kind) { - final var hashFunction = storageEngineReader.getResourceSession().getResourceConfig().nodeHashFunction; - return switch (kind) { - case OBJECT -> { - if (writeObjectSingleton == null) { - writeObjectSingleton = new ObjectNode(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, hashFunction, (byte[]) null); - } - yield writeObjectSingleton; - } - case ARRAY -> { - if (writeArraySingleton == null) { - writeArraySingleton = new ArrayNode(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, hashFunction, (byte[]) null); - } - yield writeArraySingleton; - } - case OBJECT_KEY -> { - if (writeObjectKeySingleton == null) { - writeObjectKeySingleton = new ObjectKeyNode(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, hashFunction, (byte[]) null); - } - yield writeObjectKeySingleton; - } - case STRING_VALUE -> { - if (writeStringSingleton == null) { - writeStringSingleton = new StringNode(0, 0, 0, 0, 0, 0, 0, null, hashFunction, (byte[]) null); - } - yield writeStringSingleton; - } - case NUMBER_VALUE -> { - if (writeNumberSingleton == null) { - writeNumberSingleton = new NumberNode(0, 0, 0, 0, 0, 0, 0, 0, hashFunction, (byte[]) null); - } - yield writeNumberSingleton; - } - case BOOLEAN_VALUE -> { - if (writeBooleanSingleton == null) { - writeBooleanSingleton = new BooleanNode(0, 0, 0, 0, 0, 0, 0, false, hashFunction, (byte[]) null); - } - yield writeBooleanSingleton; - } - case NULL_VALUE -> { - if (writeNullSingleton == null) { - writeNullSingleton = new NullNode(0, 0, 0, 0, 0, 0, 0, hashFunction, (byte[]) null); - } - yield writeNullSingleton; - } - case OBJECT_STRING_VALUE -> { - if (writeObjectStringSingleton == null) { - writeObjectStringSingleton = new ObjectStringNode(0, 0, 0, 0, 0, null, hashFunction, (byte[]) null); - } - yield writeObjectStringSingleton; - } - case OBJECT_NUMBER_VALUE -> { - if (writeObjectNumberSingleton == null) { - writeObjectNumberSingleton = new ObjectNumberNode(0, 0, 0, 0, 0, 0, hashFunction, (byte[]) null); - } - yield writeObjectNumberSingleton; - } - case OBJECT_BOOLEAN_VALUE -> { - if (writeObjectBooleanSingleton == null) { - writeObjectBooleanSingleton = new ObjectBooleanNode(0, 0, 0, 0, 0, false, hashFunction, (byte[]) null); - } - yield writeObjectBooleanSingleton; - } - case OBJECT_NULL_VALUE -> { - if (writeObjectNullSingleton == null) { - writeObjectNullSingleton = new ObjectNullNode(0, 0, 0, 0, 0, hashFunction, (byte[]) null); - } - yield writeObjectNullSingleton; - } - case JSON_DOCUMENT -> { - if (writeJsonDocumentSingleton == null) { - writeJsonDocumentSingleton = new JsonDocumentRootNode(0, 0, 0, 0, 0, hashFunction); - } - yield writeJsonDocumentSingleton; - } - case XML_DOCUMENT -> { - if (writeXmlDocumentSingleton == null) { - writeXmlDocumentSingleton = new XmlDocumentRootNode(0, 0, 0, 0, 0, hashFunction); - } - yield writeXmlDocumentSingleton; - } - case ELEMENT -> { - if (writeElementSingleton == null) { - writeElementSingleton = new ElementNode(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, hashFunction, - (byte[]) null, null, null, EMPTY_QNM); - } - yield writeElementSingleton; - } - case TEXT -> { - if (writeTextSingleton == null) { - writeTextSingleton = new TextNode(0, 0, 0, 0, 0, 0, 0, new byte[0], false, hashFunction, (byte[]) null); - } - yield writeTextSingleton; - } - case COMMENT -> { - if (writeCommentSingleton == null) { - writeCommentSingleton = new CommentNode(0, 0, 0, 0, 0, 0, 0, new byte[0], false, hashFunction, (byte[]) null); - } - yield writeCommentSingleton; - } - case ATTRIBUTE -> { - if (writeAttributeSingleton == null) { - writeAttributeSingleton = - new AttributeNode(0, 0, 0, 0, 0, 0, 0, 0, 0, new byte[0], hashFunction, (byte[]) null, EMPTY_QNM); - } - yield writeAttributeSingleton; - } - case NAMESPACE -> { - if (writeNamespaceSingleton == null) { - writeNamespaceSingleton = - new NamespaceNode(0, 0, 0, 0, 0, 0, 0, 0, 0, hashFunction, (byte[]) null, EMPTY_QNM); - } - yield writeNamespaceSingleton; - } - case PROCESSING_INSTRUCTION -> { - if (writePISingleton == null) { - writePISingleton = new PINode(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, new byte[0], false, hashFunction, - (byte[]) null, EMPTY_QNM); - } - yield writePISingleton; - } - default -> null; - }; - } - /** * Package-private helper class for managing the trie structure of IndirectPages. * diff --git a/bundles/sirix-core/src/main/java/io/sirix/api/StorageEngineWriter.java b/bundles/sirix-core/src/main/java/io/sirix/api/StorageEngineWriter.java index 721f9c66d..664fb425e 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/api/StorageEngineWriter.java +++ b/bundles/sirix-core/src/main/java/io/sirix/api/StorageEngineWriter.java @@ -9,6 +9,7 @@ import io.sirix.node.BytesOut; import io.sirix.node.NodeKind; import io.sirix.node.interfaces.DataRecord; +import io.sirix.page.KeyValueLeafPage; import io.sirix.page.PageReference; import io.sirix.page.UberPage; import org.checkerframework.checker.index.qual.NonNegative; @@ -85,18 +86,18 @@ public interface StorageEngineWriter extends StorageEngineReader { V prepareRecordForModification(@NonNegative long key, @NonNull IndexType indexType, int index); /** - * Persist a modified record directly back into its record-page slot. + * Persist a mutated record into the TIL's modified page. + * Ensures the record's page is prepared for modification in the TIL + * and stores the record in the modified page's records[]. * - *

- * This is the hot update path used to keep page slot memory in sync with in-memory mutable records - * without waiting for commit-time materialization. - *

+ *

This is used by mutation operations (setName, setValue, hash updates) that + * mutate the current node directly without going through prepareRecordForModification.

* - * @param record modified record to persist + * @param record the mutated record to persist * @param indexType the index type - * @param index the index number + * @param index the index number */ - void updateRecordSlot(@NonNull DataRecord record, @NonNull IndexType indexType, int index); + void persistRecord(@NonNull DataRecord record, @NonNull IndexType indexType, int index); /** * Remove an entry from the storage. @@ -181,6 +182,56 @@ default UberPage commit(@Nullable String commitMessage, @Nullable Instant commit PageContainer dereferenceRecordPageForModification(PageReference reference); + /** + * Functional interface for binding a write-path singleton to a slotted page slot. + * Set by the node transaction to enable zero-allocation write path. + */ + @FunctionalInterface + interface WriteSingletonBinder { + DataRecord bind(KeyValueLeafPage page, int offset, long nodeKey); + } + + /** + * Set the write singleton binder for zero-allocation write path. + * When set, prepareRecordForModification rebinds factory singletons instead of allocating. + * + * @param binder the write singleton binder from the node factory + */ + default void setWriteSingletonBinder(final WriteSingletonBinder binder) { + // Default no-op; NodeStorageEngineWriter overrides + } + + /** + * Allocate a record key and resolve the KVL page for direct-to-heap creation. + * After this call, read results from {@link #getAllocKvl()}, {@link #getAllocSlotOffset()}, + * {@link #getAllocNodeKey()}. + *

Only supports DOCUMENT index (the hot path). Other index types use createRecord().

+ */ + default void allocateForDocumentCreation() { + throw new UnsupportedOperationException(); + } + + /** + * Get the KVL page from the last {@link #allocateForDocumentCreation()} call. + */ + default KeyValueLeafPage getAllocKvl() { + throw new UnsupportedOperationException(); + } + + /** + * Get the slot offset from the last {@link #allocateForDocumentCreation()} call. + */ + default int getAllocSlotOffset() { + throw new UnsupportedOperationException(); + } + + /** + * Get the node key from the last {@link #allocateForDocumentCreation()} call. + */ + default long getAllocNodeKey() { + throw new UnsupportedOperationException(); + } + /** * Get the underlying {@link StorageEngineReader}. * @@ -225,4 +276,17 @@ default UberPage commit(@Nullable String commitMessage, @Nullable Instant commit * @return a PageGuard that must be closed when done with the node */ PageGuard acquireGuardForCurrentNode(); + + /** + * Get the TIL's modified {@link KeyValueLeafPage} for a given record page key, or null if not in TIL. + * Used by the singleton moveTo path to read from the correct (modified) page during write transactions. + * + * @param recordPageKey the record page key + * @param indexType the index type + * @param index the index number + * @return the modified page if in TIL, null otherwise + */ + default @Nullable KeyValueLeafPage getModifiedPageForRead(long recordPageKey, @NonNull IndexType indexType, int index) { + return null; + } } diff --git a/bundles/sirix-core/src/main/java/io/sirix/index/path/PathIndex.java b/bundles/sirix-core/src/main/java/io/sirix/index/path/PathIndex.java index c6fc26e61..6a235ab54 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/index/path/PathIndex.java +++ b/bundles/sirix-core/src/main/java/io/sirix/index/path/PathIndex.java @@ -30,16 +30,16 @@ public interface PathIndex { default Iterator openIndex(final StorageEngineReader storageEngineReader, final IndexDef indexDef, final PathFilter filter) { - + // Check if HOT is enabled (system property takes precedence, then resource config) if (isHOTEnabled(storageEngineReader)) { return openHOTIndex(storageEngineReader, indexDef, filter); } - + // Use RBTree (default) return openRBTreeIndex(storageEngineReader, indexDef, filter); } - + /** * Checks if HOT indexes should be used for reading. */ @@ -49,12 +49,12 @@ private static boolean isHOTEnabled(final StorageEngineReader storageEngineReade if (sysProp != null) { return Boolean.parseBoolean(sysProp); } - + // Fall back to resource configuration final var resourceConfig = storageEngineReader.getResourceSession().getResourceConfig(); return resourceConfig.indexBackendType == IndexBackendType.HOT; } - + /** * Open HOT-based path index. */ @@ -72,14 +72,12 @@ private Iterator openHOTIndex(final StorageEngineReader storageE return Collections.emptyIterator(); } else { // Iterate over all entries and apply filter - final Set pcrsRequested = filter != null - ? filter.getPCRs() - : Set.of(); + final Set pcrsRequested = filter != null ? filter.getPCRs() : Set.of(); final Iterator> entryIterator = reader.iterator(); - + return new Iterator<>() { private NodeReferences next = null; - + @Override public boolean hasNext() { if (next != null) { @@ -94,7 +92,7 @@ public boolean hasNext() { } return false; } - + @Override public NodeReferences next() { if (!hasNext()) { @@ -107,23 +105,26 @@ public NodeReferences next() { }; } } - + /** * Open RBTree-based path index (default). */ private Iterator openRBTreeIndex(final StorageEngineReader storageEngineReader, final IndexDef indexDef, final PathFilter filter) { - final RBTreeReader reader = RBTreeReader.getInstance( - storageEngineReader.getResourceSession().getIndexCache(), storageEngineReader, indexDef.getType(), indexDef.getID()); + final RBTreeReader reader = + RBTreeReader.getInstance(storageEngineReader.getResourceSession().getIndexCache(), + storageEngineReader, + indexDef.getType(), + indexDef.getID()); if (filter != null && filter.getPCRs().size() == 1) { - final var optionalNodeReferences = reader.get(filter.getPCRs().iterator().next(), SearchMode.EQUAL); + final var optionalNodeReferences = + reader.get(filter.getPCRs().iterator().next(), SearchMode.EQUAL); return Iterators.forArray(optionalNodeReferences.orElse(new NodeReferences())); } else { - final Iterator> iter = reader.new RBNodeIterator(Fixed.DOCUMENT_NODE_KEY.getStandardProperty()); - final Set setFilter = filter == null - ? ImmutableSet.of() - : ImmutableSet.of(filter); + final Iterator> iter = + reader.new RBNodeIterator(Fixed.DOCUMENT_NODE_KEY.getStandardProperty()); + final Set setFilter = filter == null ? ImmutableSet.of() : ImmutableSet.of(filter); return new IndexFilterAxis<>(reader, iter, setFilter); } diff --git a/bundles/sirix-core/src/main/java/io/sirix/index/path/summary/PathSummaryWriter.java b/bundles/sirix-core/src/main/java/io/sirix/index/path/summary/PathSummaryWriter.java index de35cc719..f320a40f2 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/index/path/summary/PathSummaryWriter.java +++ b/bundles/sirix-core/src/main/java/io/sirix/index/path/summary/PathSummaryWriter.java @@ -187,7 +187,11 @@ private void movePathSummary() { } else if (nodeRtx.getNode() instanceof ImmutableNameNode) { pathSummaryReader.moveTo(((ImmutableNameNode) nodeRtx.getNode()).getPathNodeKey()); } else { - throw new IllegalStateException(); + final var node = nodeRtx.getNode(); + throw new IllegalStateException("movePathSummary: unexpected node kind=" + nodeRtx.getKind() + + " nodeClass=" + (node != null ? node.getClass().getName() : "null") + + " nodeKey=" + nodeRtx.getNodeKey() + + " instanceOfImmutableNameNode=" + (node instanceof ImmutableNameNode)); } } @@ -750,11 +754,13 @@ public void remove(final ImmutableNameNode node) { } private void persistDocumentRecord(final DataRecord record) { - storageEngineWriter.updateRecordSlot(record, IndexType.DOCUMENT, -1); + // No-op: records are mutated in-place via prepareRecordForModification() + // and serialized at commit time via processEntries(). No slot sync needed. } private void persistPathSummaryRecord(final DataRecord record) { - storageEngineWriter.updateRecordSlot(record, IndexType.PATH_SUMMARY, 0); + // No-op: records are mutated in-place via prepareRecordForModification() + // and serialized at commit time via processEntries(). No slot sync needed. } @Override diff --git a/bundles/sirix-core/src/main/java/io/sirix/io/BytesUtils.java b/bundles/sirix-core/src/main/java/io/sirix/io/BytesUtils.java deleted file mode 100644 index 8c62e20c8..000000000 --- a/bundles/sirix-core/src/main/java/io/sirix/io/BytesUtils.java +++ /dev/null @@ -1,65 +0,0 @@ -package io.sirix.io; - -import io.sirix.node.BytesOut; - -import java.nio.ByteBuffer; - -public final class BytesUtils { - private BytesUtils() { - throw new AssertionError(); - } - - public static void doWrite(BytesOut bytes, ByteBuffer toWrite) { - // Write ByteBuffer content to BytesOut - byte[] buffer = new byte[toWrite.remaining()]; - toWrite.get(buffer); - bytes.write(buffer); - } - - public static void doWrite(BytesOut bytes, byte[] toWrite) { - bytes.write(toWrite); - } - - public static ByteBuffer doRead(BytesOut bytes) { - // Get underlying destination from BytesOut - Object destination = bytes.getDestination(); - if (destination instanceof ByteBuffer) { - return (ByteBuffer) destination; - } - // Fallback for other destination types - throw new UnsupportedOperationException("Unsupported destination type: " + destination.getClass()); - } - - /** - * Convert the byte[] into a String to be used for logging and debugging. - * - * @param bytes the byte[] to be dumped - * @return the String representation - */ - public static String dumpBytes(byte[] bytes) { - StringBuilder buffer = new StringBuilder("byte["); - buffer.append(bytes.length); - buffer.append("]: ["); - for (byte aByte : bytes) { - buffer.append(aByte); - buffer.append(" "); - } - buffer.append("]"); - return buffer.toString(); - } - - /** - * Convert the byteBuffer into a String to be used for logging and debugging. - * - * @param byteBuffer the byteBuffer to be dumped - * @return the String representation - */ - public static String dumpBytes(ByteBuffer byteBuffer) { - byteBuffer.mark(); - int length = byteBuffer.limit() - byteBuffer.position(); - byte[] dst = new byte[length]; - byteBuffer.get(dst); - byteBuffer.reset(); - return dumpBytes(dst); - } -} diff --git a/bundles/sirix-core/src/main/java/io/sirix/io/Writer.java b/bundles/sirix-core/src/main/java/io/sirix/io/Writer.java index f189a5a12..3a66f8c93 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/io/Writer.java +++ b/bundles/sirix-core/src/main/java/io/sirix/io/Writer.java @@ -28,8 +28,6 @@ import io.sirix.page.interfaces.Page; import io.sirix.node.BytesOut; -import java.nio.ByteBuffer; - /** * Interface to provide the abstract layer related to write access of the Sirix-backend. * diff --git a/bundles/sirix-core/src/main/java/io/sirix/io/bytepipe/FFILz4Compressor.java b/bundles/sirix-core/src/main/java/io/sirix/io/bytepipe/FFILz4Compressor.java index df530d523..5c83c3798 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/io/bytepipe/FFILz4Compressor.java +++ b/bundles/sirix-core/src/main/java/io/sirix/io/bytepipe/FFILz4Compressor.java @@ -538,7 +538,7 @@ public MemorySegment decompress(MemorySegment compressed) { } /** - * Decompress data using the unified allocator for zero-copy page support. + * Decompress data using the page allocator for zero-copy page support. * *

* Unlike the pool-based approach, this allocates from the MemorySegmentAllocator which allows @@ -585,7 +585,7 @@ public DecompressionResult decompressScoped(MemorySegment compressed) { int decompressedSize = sizeHeader; - // Use unified allocator - buffer lifetime matches page lifetime for zero-copy + // Use page allocator - buffer lifetime matches page lifetime for zero-copy // This replaces the pool-based approach to enable ownership transfer MemorySegment buffer = ALLOCATOR.allocate(decompressedSize); diff --git a/bundles/sirix-core/src/main/java/io/sirix/io/file/FileReader.java b/bundles/sirix-core/src/main/java/io/sirix/io/file/FileReader.java index a1c52aae1..caf9a5341 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/io/file/FileReader.java +++ b/bundles/sirix-core/src/main/java/io/sirix/io/file/FileReader.java @@ -49,7 +49,6 @@ import java.io.ByteArrayInputStream; import java.io.IOException; import java.io.RandomAccessFile; -import java.nio.ByteBuffer; import java.time.Instant; import static java.util.Objects.requireNonNull; @@ -211,7 +210,7 @@ public RevisionRootPage readRevisionRootPage(final int revision, final ResourceC dataFile.read(page); // Perform byte operations. - final BytesIn input = Bytes.wrapForRead(ByteBuffer.wrap(page)); // byteHandler.deserialize(Bytes.wrapForRead(ByteBuffer.wrap(page))); + final BytesIn input = Bytes.wrapForRead(page); // Return reader required to instantiate and deserialize page. return (RevisionRootPage) pagePersiter.deserializePage(resourceConfiguration, input, serializationType); diff --git a/bundles/sirix-core/src/main/java/io/sirix/io/filechannel/FileChannelWriter.java b/bundles/sirix-core/src/main/java/io/sirix/io/filechannel/FileChannelWriter.java index 289b9056d..6ec3ae3f7 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/io/filechannel/FileChannelWriter.java +++ b/bundles/sirix-core/src/main/java/io/sirix/io/filechannel/FileChannelWriter.java @@ -181,13 +181,21 @@ private byte[] buildSerializedPage(final ResourceConfiguration resourceConfigura throws IOException { final BytesIn uncompressedBytes = byteBufferBytes.bytesForRead(); - if (page instanceof KeyValueLeafPage keyValueLeafPage && keyValueLeafPage.getBytes() != null) { + if (page instanceof KeyValueLeafPage keyValueLeafPage) { + // Check compressed MemorySegment cache first (slotted page format path) + final MemorySegment cachedSegment = keyValueLeafPage.getCompressedSegment(); + if (cachedSegment != null) { + return segmentToByteArray(cachedSegment); + } + // Check legacy byte[] cache final var cached = keyValueLeafPage.getBytes(); - if (cached instanceof MemorySegmentBytesOut msOut) { - MemorySegment segment = msOut.getDestination(); - return segmentToByteArray(segment); + if (cached != null) { + if (cached instanceof MemorySegmentBytesOut msOut) { + MemorySegment segment = msOut.getDestination(); + return segmentToByteArray(segment); + } + return cached.toByteArray(); } - return cached.toByteArray(); } final var pipeline = resourceConfiguration.byteHandlePipeline; @@ -268,11 +276,12 @@ private FileChannelWriter writePageReference(final ResourceConfiguration resourc buffer.position(8); buffer.putLong(revisionRootPage.getRevisionTimestamp()); buffer.position(0); + final long revisionsFileSize = revisionsFileChannel.size(); final long revisionsFileOffset; if (revisionRootPage.getRevision() == 0) { - revisionsFileOffset = revisionsFileChannel.size() + IOStorage.FIRST_BEACON; + revisionsFileOffset = revisionsFileSize + IOStorage.FIRST_BEACON; } else { - revisionsFileOffset = revisionsFileChannel.size(); + revisionsFileOffset = revisionsFileSize; } revisionsFileChannel.write(buffer, revisionsFileOffset); final long currOffset = offset; @@ -334,9 +343,8 @@ public Writer writeUberPageReference(final ResourceConfiguration resourceConfigu isFirstUberPage = false; writePageReference(resourceConfiguration, pageReference, page, bufferedBytes, IOStorage.FIRST_BEACON >> 1); - @SuppressWarnings("DataFlowIssue") - final var buffer = ((ByteBuffer) bufferedBytes.underlyingObject()).rewind(); - buffer.limit((int) bufferedBytes.readLimit()); + final var segment = (MemorySegment) bufferedBytes.underlyingObject(); + final var buffer = segment.asByteBuffer(); dataFileChannel.write(buffer, 0L); // NOTE: force() removed here - now called via forceAll() at end of commit for single barrier bufferedBytes.clear(); @@ -372,9 +380,8 @@ private void flushBuffer(BytesOut bufferedBytes) throws IOException { offset = fileSize; } - @SuppressWarnings("DataFlowIssue") - final var buffer = ((ByteBuffer) bufferedBytes.underlyingObject()).rewind(); - buffer.limit((int) bufferedBytes.readLimit()); + final var segment = (MemorySegment) bufferedBytes.underlyingObject(); + final var buffer = segment.asByteBuffer(); dataFileChannel.write(buffer, offset); bufferedBytes.clear(); } diff --git a/bundles/sirix-core/src/main/java/io/sirix/io/memorymapped/MMFileWriter.java b/bundles/sirix-core/src/main/java/io/sirix/io/memorymapped/MMFileWriter.java index c71af3bf1..3ee36270c 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/io/memorymapped/MMFileWriter.java +++ b/bundles/sirix-core/src/main/java/io/sirix/io/memorymapped/MMFileWriter.java @@ -260,13 +260,21 @@ private byte[] buildSerializedPage(final ResourceConfiguration resourceConfigura throws IOException { final BytesIn uncompressedBytes = byteBufferBytes.bytesForRead(); - if (page instanceof KeyValueLeafPage keyValueLeafPage && keyValueLeafPage.getBytes() != null) { + if (page instanceof KeyValueLeafPage keyValueLeafPage) { + // Check compressed MemorySegment cache first (slotted page format path) + final MemorySegment cachedSegment = keyValueLeafPage.getCompressedSegment(); + if (cachedSegment != null) { + return cachedSegment.toArray(ValueLayout.JAVA_BYTE); + } + // Check legacy byte[] cache final var cached = keyValueLeafPage.getBytes(); - if (cached instanceof MemorySegmentBytesOut msOut) { - MemorySegment segment = msOut.getDestination(); - return segment.toArray(ValueLayout.JAVA_BYTE); + if (cached != null) { + if (cached instanceof MemorySegmentBytesOut msOut) { + MemorySegment segment = msOut.getDestination(); + return segment.toArray(ValueLayout.JAVA_BYTE); + } + return cached.toByteArray(); } - return cached.toByteArray(); } final var pipeline = resourceConfiguration.byteHandlePipeline; diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/AbstractForwardingNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/AbstractForwardingNode.java index 19f84df1a..ebf818d47 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/node/AbstractForwardingNode.java +++ b/bundles/sirix-core/src/main/java/io/sirix/node/AbstractForwardingNode.java @@ -7,7 +7,6 @@ import io.sirix.node.delegates.NodeDelegate; import io.sirix.node.interfaces.Node; -import java.nio.ByteBuffer; /** * Skeletal implementation of {@link Node} interface. diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/Bytes.java b/bundles/sirix-core/src/main/java/io/sirix/node/Bytes.java index 9bc251a45..6bdc61a01 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/node/Bytes.java +++ b/bundles/sirix-core/src/main/java/io/sirix/node/Bytes.java @@ -1,7 +1,6 @@ package io.sirix.node; import java.lang.foreign.MemorySegment; -import java.nio.ByteBuffer; /** * Utility class to replace Chronicle Bytes factory methods. Provides factory methods for creating @@ -102,28 +101,6 @@ public static BytesIn wrapForRead(MemorySegment segment) { return new MemorySegmentBytesIn(segment); } - /** - * Factory method to wrap a ByteBuffer for reading. If the buffer has a backing array, uses - * zero-copy wrapping. Otherwise, copies the data to a new array. - * - * @param buffer the ByteBuffer to wrap - * @return a BytesIn instance for reading - */ - public static BytesIn wrapForRead(ByteBuffer buffer) { - if (buffer.hasArray()) { - // Zero-copy path for heap buffers with backing array - int offset = buffer.arrayOffset() + buffer.position(); - int length = buffer.remaining(); - MemorySegment segment = MemorySegment.ofArray(buffer.array()).asSlice(offset, length); - return new MemorySegmentBytesIn(segment); - } else { - // Fallback: copy data for direct buffers without backing array - byte[] data = new byte[buffer.remaining()]; - buffer.get(data); - return wrapForRead(data); - } - } - /** * Factory method to create an elastic heap BytesOut with initial capacity. * diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/BytesOut.java b/bundles/sirix-core/src/main/java/io/sirix/node/BytesOut.java index 59f11a49a..f954a02c1 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/node/BytesOut.java +++ b/bundles/sirix-core/src/main/java/io/sirix/node/BytesOut.java @@ -2,7 +2,6 @@ import java.lang.foreign.MemorySegment; import java.math.BigInteger; -import java.nio.ByteBuffer; import net.openhft.hashing.LongHashFunction; /** @@ -149,17 +148,6 @@ default BytesOut writeSegment(MemorySegment source, long sourceOffset, long l return write(temp); } - /** - * Write from a ByteBuffer at a specific position. - * - * @param position the position to write at - * @param buffer the buffer to write from - * @param bufferPosition the position in the buffer - * @param length the number of bytes to write - * @return this BytesOut for method chaining - */ - BytesOut write(long position, ByteBuffer buffer, int bufferPosition, int length); - /** * Get the current write position. * diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/DeltaVarIntCodec.java b/bundles/sirix-core/src/main/java/io/sirix/node/DeltaVarIntCodec.java index c1cbf77d8..f65fdab80 100644 --- a/bundles/sirix-core/src/main/java/io/sirix/node/DeltaVarIntCodec.java +++ b/bundles/sirix-core/src/main/java/io/sirix/node/DeltaVarIntCodec.java @@ -36,22 +36,19 @@ /** * High-performance codec for delta-encoded node keys using zigzag + varint encoding. * - *

- * Inspired by Umbra-style storage optimization: instead of storing absolute 8-byte keys, we store - * deltas relative to the current nodeKey. Since siblings are usually adjacent (delta = ±1) and - * parents are nearby, deltas are small and compress well. + *

Inspired by Umbra-style storage optimization: instead of storing absolute 8-byte keys, + * we store deltas relative to the current nodeKey. Since siblings are usually adjacent + * (delta = ±1) and parents are nearby, deltas are small and compress well. * *

Encoding Strategy

*
    - *
  • NULL keys: Encoded as a single byte 0x00 (zigzag of 0 with special meaning)
    • - *
  • Delta encoding: Store (targetKey - baseKey) instead of absolute key
    • - *
  • Zigzag encoding: Maps signed to unsigned (0→0, -1→1, 1→2, -2→3, 2→4, ...)
    • - *
  • Varint encoding: Variable-length unsigned integer (7 bits per byte, MSB = - * continue)
    • + *
  • NULL keys: Encoded as a single byte 0x00 (zigzag of 0 with special meaning)
    • + *
  • Delta encoding: Store (targetKey - baseKey) instead of absolute key
    • + *
  • Zigzag encoding: Maps signed to unsigned (0→0, -1→1, 1→2, -2→3, 2→4, ...)
    • + *
  • Varint encoding: Variable-length unsigned integer (7 bits per byte, MSB = continue)
    • *
* *

Space Savings Example

- * * 
  * Absolute key 1000000 (8 bytes) → Delta +1 → Zigzag 2 → Varint 1 byte
  * Absolute key -1 (NULL, 8 bytes) → Special marker → 1 byte
@@ -59,41 +56,40 @@
  * 
  * 
Performance

  * 
    
- * 
  • No allocations during encode/decode
    • 
- * 
  • Branchless zigzag encoding
    • 
- * 
  • Unrolled varint for common cases (1-2 bytes)
    • 
+ *   
  • No allocations during encode/decode
    • 
+ *   
  • Branchless zigzag encoding
    • 
+ *   
  • Unrolled varint for common cases (1-2 bytes)
    • 
  * 

  * 
  * @author Johannes Lichtenberger
  */
 public final class DeltaVarIntCodec {
-
+  
   /**
-   * Sentinel value for NULL node keys. We use 0 in zigzag encoding as the NULL marker since delta=0
-   * (self-reference) is meaningless.
+   * Sentinel value for NULL node keys.
+   * We use 0 in zigzag encoding as the NULL marker since delta=0 (self-reference) is meaningless.
    */
   private static final int NULL_MARKER = 0;
-
+  
   /**
    * The actual NULL key value from the Fixed enum.
    */
   private static final long NULL_KEY = Fixed.NULL_NODE_KEY.getStandardProperty();
-
+  
   private DeltaVarIntCodec() {
     // Utility class
   }
-
+  
   // ==================== ENCODING ====================
-
+  
   /**
    * Encode a node key as a delta from a base key.
    * 
-   * 

-   * For structural pointers (siblings, children), the base is typically the current nodeKey. For
-   * parent pointers, the base is also the current nodeKey.
+   * 
For structural pointers (siblings, children), the base is typically the current nodeKey.
+   * For parent pointers, the base is also the current nodeKey.
    * 
-   * @param sink output sink to write to
-   * @param key the key to encode (may be NULL_NODE_KEY)
+   * @param sink    output sink to write to
+   * @param key     the key to encode (may be NULL_NODE_KEY)
    * @param baseKey the reference key for delta calculation
    */
   public static void encodeDelta(BytesOut sink, long key, long baseKey) {
@@ -102,26 +98,26 @@ public static void encodeDelta(BytesOut sink, long key, long baseKey) {
       sink.writeByte((byte) NULL_MARKER);
       return;
     }
-
+    
     // Calculate delta
     long delta = key - baseKey;
-
+    
     // Zigzag encode (signed → unsigned)
     // This maps small positive/negative values to small unsigned values:
     // 0 → 0, -1 → 1, 1 → 2, -2 → 3, 2 → 4, ...
     // But we reserve 0 for NULL, so we add 1 to shift everything up
     long zigzag = zigzagEncode(delta) + 1;
-
+    
     // Varint encode
     writeVarLong(sink, zigzag);
   }
-
+  
   /**
-   * Encode an absolute key (no delta, used for nodeKey itself). Uses varint encoding directly for
-   * unsigned values.
+   * Encode an absolute key (no delta, used for nodeKey itself).
+   * Uses varint encoding directly for unsigned values.
    * 
    * @param sink output sink
-   * @param key the absolute key (must be non-negative)
+   * @param key  the absolute key (must be non-negative)
    */
   public static void encodeAbsolute(BytesOut sink, long key) {
     if (key < 0) {
@@ -129,10 +125,10 @@ public static void encodeAbsolute(BytesOut sink, long key) {
     }
     writeVarLong(sink, key);
   }
-
+  
   /**
-   * Encode a revision number which can be -1 (NULL_REVISION_NUMBER). Uses zigzag encoding to handle
-   * the -1 case efficiently.
+   * Encode a revision number which can be -1 (NULL_REVISION_NUMBER).
+   * Uses zigzag encoding to handle the -1 case efficiently.
    * 
    * @param sink output sink
    * @param revision the revision number (can be -1)
@@ -143,7 +139,7 @@ public static void encodeRevision(BytesOut sink, int revision) {
     long zigzag = zigzagEncode(revision);
     writeVarLong(sink, zigzag);
   }
-
+  
   /**
    * Decode a revision number which can be -1 (NULL_REVISION_NUMBER).
    * 
@@ -154,10 +150,10 @@ public static int decodeRevision(BytesIn source) {
     long zigzag = readVarLong(source);
     return (int) zigzagDecode(zigzag);
   }
-
+  
   /**
-   * Encode a signed integer (like nameKey which is a hash and can be negative). Uses zigzag encoding
-   * to handle negative values efficiently.
+   * Encode a signed integer (like nameKey which is a hash and can be negative).
+   * Uses zigzag encoding to handle negative values efficiently.
    * 
    * @param sink output sink
    * @param value the signed integer value
@@ -166,7 +162,7 @@ public static void encodeSigned(BytesOut sink, int value) {
     long zigzag = zigzagEncode(value);
     writeVarLong(sink, zigzag);
   }
-
+  
   /**
    * Decode a signed integer.
    * 
@@ -177,13 +173,12 @@ public static int decodeSigned(BytesIn source) {
     long zigzag = readVarLong(source);
     return (int) zigzagDecode(zigzag);
   }
-
+  
   /**
-   * Encode a signed long value using zigzag + varint encoding. Optimized for small values: values -64
-   * to 63 use 1 byte, -8192 to 8191 use 2 bytes.
+   * Encode a signed long value using zigzag + varint encoding.
+   * Optimized for small values: values -64 to 63 use 1 byte, -8192 to 8191 use 2 bytes.
    * 
-   * 

-   * This is ideal for JSON numbers which are often small integers stored as long.
+   * 
This is ideal for JSON numbers which are often small integers stored as long.
    * 
    * @param sink output sink
    * @param value the signed long value
@@ -192,7 +187,7 @@ public static void encodeSignedLong(BytesOut sink, long value) {
     long zigzag = zigzagEncode(value);
     writeVarLong(sink, zigzag);
   }
-
+  
   /**
    * Decode a signed long value from zigzag + varint encoding.
    * 
@@ -203,10 +198,10 @@ public static long decodeSignedLong(BytesIn source) {
     long zigzag = readVarLong(source);
     return zigzagDecode(zigzag);
   }
-
+  
   /**
-   * Encode an unsigned long value using varint encoding. Optimized for small values: values 0-127 use
-   * 1 byte, 128-16383 use 2 bytes.
+   * Encode an unsigned long value using varint encoding.
+   * Optimized for small values: values 0-127 use 1 byte, 128-16383 use 2 bytes.
    * 
    * @param sink output sink
    * @param value the unsigned long value (must be non-negative)
@@ -214,7 +209,7 @@ public static long decodeSignedLong(BytesIn source) {
   public static void encodeUnsignedLong(BytesOut sink, long value) {
     writeVarLong(sink, value);
   }
-
+  
   /**
    * Decode an unsigned long value from varint encoding.
    * 
@@ -224,29 +219,29 @@ public static void encodeUnsignedLong(BytesOut sink, long value) {
   public static long decodeUnsignedLong(BytesIn source) {
     return readVarLong(source);
   }
-
+  
   // ==================== DECODING ====================
-
+  
   /**
    * Decode a delta-encoded node key.
    * 
-   * @param source input source to read from
+   * @param source  input source to read from
    * @param baseKey the reference key for delta calculation
    * @return the decoded absolute key, or NULL_NODE_KEY if null marker
    */
   public static long decodeDelta(BytesIn source, long baseKey) {
     long zigzag = readVarLong(source);
-
+    
     if (zigzag == NULL_MARKER) {
       return NULL_KEY;
     }
-
+    
     // Undo the +1 shift and zigzag decode
     long delta = zigzagDecode(zigzag - 1);
-
+    
     return baseKey + delta;
   }
-
+  
   /**
    * Decode an absolute key (no delta).
    * 
@@ -256,33 +251,34 @@ public static long decodeDelta(BytesIn source, long baseKey) {
   public static long decodeAbsolute(BytesIn source) {
     return readVarLong(source);
   }
-
+  
   // ==================== ZIGZAG ENCODING ====================
-
+  
   /**
-   * Zigzag encode a signed long to unsigned. Maps: 0→0, -1→1, 1→2, -2→3, 2→4, ...
+   * Zigzag encode a signed long to unsigned.
+   * Maps: 0→0, -1→1, 1→2, -2→3, 2→4, ...
    * 
-   * 

-   * This is branchless and uses arithmetic shift.
+   * 
This is branchless and uses arithmetic shift.
    */
   private static long zigzagEncode(long value) {
     return (value << 1) ^ (value >> 63);
   }
-
+  
   /**
-   * Zigzag decode an unsigned long to signed. Inverse of zigzagEncode.
+   * Zigzag decode an unsigned long to signed.
+   * Inverse of zigzagEncode.
    */
   private static long zigzagDecode(long encoded) {
     return (encoded >>> 1) ^ -(encoded & 1);
   }
-
+  
   // ==================== VARINT ENCODING ====================
-
+  
   /**
-   * Write a variable-length unsigned long. Uses 7 bits per byte, MSB indicates continuation.
+   * Write a variable-length unsigned long.
+   * Uses 7 bits per byte, MSB indicates continuation.
    * 
-   * 

-   * Optimized for small values (1-2 bytes for values 0-16383).
+   * 
Optimized for small values (1-2 bytes for values 0-16383).
    */
   private static void writeVarLong(BytesOut sink, long value) {
     // Fast path for small values (fits in 1 byte: 0-127)
@@ -290,14 +286,14 @@ private static void writeVarLong(BytesOut sink, long value) {
       sink.writeByte((byte) value);
       return;
     }
-
+    
     // Fast path for 2-byte values (128-16383)
     if ((value & ~0x3FFFL) == 0) {
       sink.writeByte((byte) ((value & 0x7F) | 0x80));
       sink.writeByte((byte) (value >>> 7));
       return;
     }
-
+    
     // General case for larger values
     while ((value & ~0x7FL) != 0) {
       sink.writeByte((byte) ((value & 0x7F) | 0x80));
@@ -305,68 +301,46 @@ private static void writeVarLong(BytesOut sink, long value) {
     }
     sink.writeByte((byte) value);
   }
-
+  
   /**
    * Read a variable-length unsigned long.
    * 
-   * 

-   * Optimized with fast paths for common 1-byte and 2-byte cases. Most delta-encoded values (siblings
-   * ±1, nearby parents) fit in 1-2 bytes.
+   * 
Optimized with fast paths for common 1-byte and 2-byte cases.
+   * Most delta-encoded values (siblings ±1, nearby parents) fit in 1-2 bytes.
    */
   private static long readVarLong(BytesIn source) {
     byte b = source.readByte();
-
+    
     // Fast path: 1 byte (0-127) - most common case for small deltas
     if ((b & 0x80) == 0) {
       return b;
     }
-
+    
     long result = b & 0x7F;
     b = source.readByte();
-
+    
     // Fast path: 2 bytes (128-16383) - second most common
     if ((b & 0x80) == 0) {
       return result | ((long) b << 7);
     }
-
+    
     // General case for larger values (rare for structural keys)
     result |= (long) (b & 0x7F) << 7;
     int shift = 14;
-    while (true) {
-      if (shift >= Long.SIZE) {
-        throw new IllegalStateException("Varint too long (more than 10 bytes)");
-      }
-
+    do {
       b = source.readByte();
-      if (shift == Long.SIZE - 1 && (b & 0x7E) != 0) {
-        throw new IllegalStateException("Varint exceeds 64-bit range");
-      }
       result |= (long) (b & 0x7F) << shift;
-      if ((b & 0x80) == 0) {
-        return result;
-      }
       shift += 7;
-    }
-  }
-
-  // ==================== SIZE ESTIMATION ====================
 
-  /**
-   * Estimate the encoded size of a delta-encoded key (for buffer sizing).
-   * 
-   * @param key the key to encode
-   * @param baseKey the reference key
-   * @return estimated bytes needed
-   */
-  public static int estimateEncodedSize(long key, long baseKey) {
-    if (key == NULL_KEY) {
-      return 1;
-    }
+      if (shift > 70) {
+        throw new IllegalStateException("Varint too long (more than 10 bytes)");
+      }
+    } while ((b & 0x80) != 0);
 
-    long delta = key - baseKey;
-    long zigzag = zigzagEncode(delta) + 1;
-    return varLongSize(zigzag);
+    return result;
   }
+  
+  // ==================== SIZE ESTIMATION ====================
 
   /**
    * Calculate the number of bytes needed for a varint.
@@ -379,16 +353,16 @@ private static int varLongSize(long value) {
     }
     return size;
   }
-
+  
   // ==================== DIRECT SEGMENT WRITE METHODS ====================
   // These methods eliminate per-byte ensureCapacity() overhead by using direct segment writes
-
+  
   /**
-   * Encode a node key as a delta from a base key, writing directly to a GrowingMemorySegment. This is
-   * the high-performance variant that eliminates per-byte capacity checks.
+   * Encode a node key as a delta from a base key, writing directly to a GrowingMemorySegment.
+   * This is the high-performance variant that eliminates per-byte capacity checks.
    * 
-   * @param seg the segment to write to
-   * @param key the key to encode (may be NULL_NODE_KEY)
+   * @param seg     the segment to write to
+   * @param key     the key to encode (may be NULL_NODE_KEY)
    * @param baseKey the reference key for delta calculation
    */
   public static void encodeDelta(GrowingMemorySegment seg, long key, long baseKey) {
@@ -397,21 +371,21 @@ public static void encodeDelta(GrowingMemorySegment seg, long key, long baseKey)
       seg.writeByte((byte) NULL_MARKER);
       return;
     }
-
+    
     // Calculate delta and zigzag encode (add 1 to reserve 0 for NULL)
     long delta = key - baseKey;
     long zigzag = zigzagEncode(delta) + 1;
-
+    
     // Use direct varint write (single ensureCapacity call)
     seg.writeVarLong(zigzag);
   }
-
+  
   /**
-   * Encode a node key as a delta from a base key, writing directly to a PooledGrowingSegment. This is
-   * the high-performance variant that eliminates per-byte capacity checks.
+   * Encode a node key as a delta from a base key, writing directly to a PooledGrowingSegment.
+   * This is the high-performance variant that eliminates per-byte capacity checks.
    * 
-   * @param seg the segment to write to
-   * @param key the key to encode (may be NULL_NODE_KEY)
+   * @param seg     the segment to write to
+   * @param key     the key to encode (may be NULL_NODE_KEY)
    * @param baseKey the reference key for delta calculation
    */
   public static void encodeDelta(PooledGrowingSegment seg, long key, long baseKey) {
@@ -420,15 +394,15 @@ public static void encodeDelta(PooledGrowingSegment seg, long key, long baseKey)
       seg.writeByte((byte) NULL_MARKER);
       return;
     }
-
+    
     // Calculate delta and zigzag encode (add 1 to reserve 0 for NULL)
     long delta = key - baseKey;
     long zigzag = zigzagEncode(delta) + 1;
-
+    
     // Use direct varint write (single ensureCapacity call)
     seg.writeVarLong(zigzag);
   }
-
+  
   /**
    * Encode an absolute key directly to a GrowingMemorySegment.
    * 
@@ -441,7 +415,7 @@ public static void encodeAbsolute(GrowingMemorySegment seg, long key) {
     }
     seg.writeVarLong(key);
   }
-
+  
   /**
    * Encode an absolute key directly to a PooledGrowingSegment.
    * 
@@ -454,149 +428,147 @@ public static void encodeAbsolute(PooledGrowingSegment seg, long key) {
     }
     seg.writeVarLong(key);
   }
-
+  
   /**
    * Encode a signed long value using zigzag + varint directly to a GrowingMemorySegment.
    * 
-   * @param seg the segment to write to
+   * @param seg   the segment to write to
    * @param value the signed long value
    */
   public static void encodeSignedLong(GrowingMemorySegment seg, long value) {
     long zigzag = zigzagEncode(value);
     seg.writeVarLong(zigzag);
   }
-
+  
   /**
    * Encode a signed long value using zigzag + varint directly to a PooledGrowingSegment.
    * 
-   * @param seg the segment to write to
+   * @param seg   the segment to write to
    * @param value the signed long value
    */
   public static void encodeSignedLong(PooledGrowingSegment seg, long value) {
     long zigzag = zigzagEncode(value);
     seg.writeVarLong(zigzag);
   }
-
+  
   /**
    * Encode an unsigned long value using varint directly to a GrowingMemorySegment.
    * 
-   * @param seg the segment to write to
+   * @param seg   the segment to write to
    * @param value the unsigned long value (must be non-negative)
    */
   public static void encodeUnsignedLong(GrowingMemorySegment seg, long value) {
     seg.writeVarLong(value);
   }
-
+  
   /**
    * Encode an unsigned long value using varint directly to a PooledGrowingSegment.
    * 
-   * @param seg the segment to write to
+   * @param seg   the segment to write to
    * @param value the unsigned long value (must be non-negative)
    */
   public static void encodeUnsignedLong(PooledGrowingSegment seg, long value) {
     seg.writeVarLong(value);
   }
-
+  
   // ==================== MEMORY SEGMENT SUPPORT ====================
   // These methods support zero-allocation access by reading directly from MemorySegment
-
+  
   /**
-   * Decode a delta-encoded key directly from MemorySegment. ZERO ALLOCATION - reads directly from
-   * memory.
+   * Decode a delta-encoded key directly from MemorySegment.
+   * ZERO ALLOCATION - reads directly from memory.
    *
    * @param segment the MemorySegment containing the data
-   * @param offset the byte offset to start reading from
+   * @param offset  the byte offset to start reading from
    * @param baseKey the reference key for delta calculation
    * @return the decoded key
    */
   public static long decodeDeltaFromSegment(MemorySegment segment, int offset, long baseKey) {
     long zigzag = readVarLongFromSegment(segment, offset);
-
+    
     if (zigzag == NULL_MARKER) {
       return NULL_KEY;
     }
-
+    
     // Undo the +1 shift and zigzag decode
     long delta = zigzagDecode(zigzag - 1);
     return baseKey + delta;
   }
-
+  
   /**
-   * Read unsigned varint from MemorySegment. ZERO ALLOCATION - reads directly from memory.
+   * Read unsigned varint from MemorySegment.
+   * ZERO ALLOCATION - reads directly from memory.
    *
    * @param segment the MemorySegment containing the data
-   * @param offset the byte offset to start reading from
+   * @param offset  the byte offset to start reading from
    * @return the decoded unsigned long value
    */
   public static long readVarLongFromSegment(MemorySegment segment, int offset) {
     byte b = segment.get(ValueLayout.JAVA_BYTE, offset);
-
+    
     // Fast path: 1 byte (0-127) - most common case for small deltas
     if ((b & 0x80) == 0) {
       return b;
     }
-
+    
     long result = b & 0x7F;
     b = segment.get(ValueLayout.JAVA_BYTE, offset + 1);
-
+    
     // Fast path: 2 bytes (128-16383) - second most common
     if ((b & 0x80) == 0) {
       return result | ((long) b << 7);
     }
-
+    
     // General case for larger values (rare for structural keys)
     result |= (long) (b & 0x7F) << 7;
     int pos = offset + 2;
     int shift = 14;
-    while (true) {
-      if (shift >= Long.SIZE) {
-        throw new IllegalStateException("Varint too long (more than 10 bytes)");
-      }
-
+    do {
       b = segment.get(ValueLayout.JAVA_BYTE, pos++);
-      if (shift == Long.SIZE - 1 && (b & 0x7E) != 0) {
-        throw new IllegalStateException("Varint exceeds 64-bit range");
-      }
       result |= (long) (b & 0x7F) << shift;
-      if ((b & 0x80) == 0) {
-        return result;
-      }
       shift += 7;
-    }
-  }
 
+      if (shift > 70) {
+        throw new IllegalStateException("Varint too long (more than 10 bytes)");
+      }
+    } while ((b & 0x80) != 0);
+
+    return result;
+  }
+  
   /**
-   * Read signed varint (zigzag decoded) from MemorySegment. ZERO ALLOCATION - reads directly from
-   * memory.
+   * Read signed varint (zigzag decoded) from MemorySegment.
+   * ZERO ALLOCATION - reads directly from memory.
    *
    * @param segment the MemorySegment containing the data
-   * @param offset the byte offset to start reading from
+   * @param offset  the byte offset to start reading from
    * @return the decoded signed integer value
    */
   public static int decodeSignedFromSegment(MemorySegment segment, int offset) {
     long zigzag = readVarLongFromSegment(segment, offset);
     return (int) zigzagDecode(zigzag);
   }
-
+  
   /**
-   * Read signed long (zigzag decoded) from MemorySegment. ZERO ALLOCATION - reads directly from
-   * memory.
+   * Read signed long (zigzag decoded) from MemorySegment.
+   * ZERO ALLOCATION - reads directly from memory.
    *
    * @param segment the MemorySegment containing the data
-   * @param offset the byte offset to start reading from
+   * @param offset  the byte offset to start reading from
    * @return the decoded signed long value
    */
   public static long decodeSignedLongFromSegment(MemorySegment segment, int offset) {
     long zigzag = readVarLongFromSegment(segment, offset);
     return zigzagDecode(zigzag);
   }
-
+  
   /**
-   * Get the byte length of a varint at the given offset. Used for computing field offsets during
-   * flyweight cursor parsing. ZERO ALLOCATION - reads directly from memory.
+   * Get the byte length of a varint at the given offset.
+   * Used for computing field offsets during flyweight cursor parsing.
+   * ZERO ALLOCATION - reads directly from memory.
    *
    * @param segment the MemorySegment containing the data
-   * @param offset the byte offset to start reading from
+   * @param offset  the byte offset to start reading from
    * @return the number of bytes this varint occupies
    */
   public static int varintLength(MemorySegment segment, int offset) {
@@ -606,32 +578,413 @@ public static int varintLength(MemorySegment segment, int offset) {
     }
     return len + 1;
   }
-
+  
   /**
-   * Get length of a delta-encoded value (includes NULL check). ZERO ALLOCATION - reads directly from
-   * memory.
+   * Get length of a delta-encoded value (includes NULL check).
+   * ZERO ALLOCATION - reads directly from memory.
    *
    * @param segment the MemorySegment containing the data
-   * @param offset the byte offset to start reading from
+   * @param offset  the byte offset to start reading from
    * @return the number of bytes this delta-encoded value occupies
    */
   public static int deltaLength(MemorySegment segment, int offset) {
     byte first = segment.get(ValueLayout.JAVA_BYTE, offset);
     if (first == NULL_MARKER) {
-      return 1; // NULL is single byte
+      return 1;  // NULL is single byte
     }
     return varintLength(segment, offset);
   }
-
+  
   /**
-   * Read a fixed 8-byte long value from MemorySegment. Used for hash values which are stored as
-   * fixed-length. ZERO ALLOCATION - reads directly from memory.
+   * Read a fixed 8-byte long value from MemorySegment.
+   * Used for hash values which are stored as fixed-length.
+   * ZERO ALLOCATION - reads directly from memory.
    *
    * @param segment the MemorySegment containing the data
-   * @param offset the byte offset to start reading from
+   * @param offset  the byte offset to start reading from
    * @return the 8-byte long value
    */
   public static long readLongFromSegment(MemorySegment segment, int offset) {
     return segment.get(ValueLayout.JAVA_LONG_UNALIGNED, offset);
   }
+
+  // ==================== DIRECT SEGMENT WRITE METHODS (for in-place mutation) ====================
+
+  /**
+   * Write a fixed 8-byte long value directly to a MemorySegment.
+   * Used for hash values which are always fixed-width, enabling in-place mutation.
+   * ZERO ALLOCATION.
+   *
+   * @param segment the MemorySegment to write to
+   * @param offset  the byte offset to write at
+   * @param value   the 8-byte long value
+   */
+  public static void writeLongToSegment(MemorySegment segment, long offset, long value) {
+    segment.set(ValueLayout.JAVA_LONG_UNALIGNED, offset, value);
+  }
+
+  /**
+   * Compute the encoded byte width of a delta-encoded key.
+   * This is critical for in-place mutation: if the new width matches the old width,
+   * we can overwrite in-place without re-serializing the record.
+   *
+   * @param key     the key to encode
+   * @param baseKey the reference key for delta calculation
+   * @return the number of bytes this delta would occupy
+   */
+  public static int computeDeltaEncodedWidth(long key, long baseKey) {
+    if (key == NULL_KEY) {
+      return 1;
+    }
+    long delta = key - baseKey;
+    long zigzag = zigzagEncode(delta) + 1;
+    return varLongSize(zigzag);
+  }
+
+  /**
+   * Compute the encoded byte width of a signed integer (zigzag + varint).
+   *
+   * @param value the signed integer value
+   * @return the number of bytes this value would occupy
+   */
+  public static int computeSignedEncodedWidth(int value) {
+    long zigzag = zigzagEncode(value);
+    return varLongSize(zigzag);
+  }
+
+  /**
+   * Compute the encoded byte width of a signed long (zigzag + varint).
+   *
+   * @param value the signed long value
+   * @return the number of bytes this value would occupy
+   */
+  public static int computeSignedLongEncodedWidth(long value) {
+    long zigzag = zigzagEncode(value);
+    return varLongSize(zigzag);
+  }
+
+  /**
+   * Write a delta-encoded key directly to a MemorySegment at the given offset.
+   * ZERO ALLOCATION - writes directly to page memory.
+   *
+   * @param segment the MemorySegment to write to
+   * @param offset  the byte offset to start writing at
+   * @param key     the key to encode (may be NULL_NODE_KEY)
+   * @param baseKey the reference key for delta calculation
+   * @return the number of bytes written
+   */
+  public static int writeDeltaToSegment(MemorySegment segment, long offset, long key, long baseKey) {
+    if (key == NULL_KEY) {
+      segment.set(ValueLayout.JAVA_BYTE, offset, (byte) NULL_MARKER);
+      return 1;
+    }
+
+    long delta = key - baseKey;
+    long zigzag = zigzagEncode(delta) + 1;
+    return writeVarLongToSegment(segment, offset, zigzag);
+  }
+
+  /**
+   * Write a signed integer (zigzag + varint) directly to a MemorySegment.
+   * ZERO ALLOCATION.
+   *
+   * @param segment the MemorySegment to write to
+   * @param offset  the byte offset to start writing at
+   * @param value   the signed integer value
+   * @return the number of bytes written
+   */
+  public static int writeSignedToSegment(MemorySegment segment, long offset, int value) {
+    long zigzag = zigzagEncode(value);
+    return writeVarLongToSegment(segment, offset, zigzag);
+  }
+
+  /**
+   * Write a signed long (zigzag + varint) directly to a MemorySegment.
+   * ZERO ALLOCATION.
+   *
+   * @param segment the MemorySegment to write to
+   * @param offset  the byte offset to start writing at
+   * @param value   the signed long value
+   * @return the number of bytes written
+   */
+  public static int writeSignedLongToSegment(MemorySegment segment, long offset, long value) {
+    long zigzag = zigzagEncode(value);
+    return writeVarLongToSegment(segment, offset, zigzag);
+  }
+
+  /**
+   * Write an unsigned varint directly to a MemorySegment.
+   * ZERO ALLOCATION - optimized with fast paths for 1-2 byte values.
+   *
+   * @param segment the MemorySegment to write to
+   * @param offset  the byte offset to start writing at
+   * @param value   the unsigned long value
+   * @return the number of bytes written
+   */
+  public static int writeVarLongToSegment(MemorySegment segment, long offset, long value) {
+    // Fast path for 1-byte values (0-127)
+    if ((value & ~0x7FL) == 0) {
+      segment.set(ValueLayout.JAVA_BYTE, offset, (byte) value);
+      return 1;
+    }
+
+    // Fast path for 2-byte values (128-16383)
+    if ((value & ~0x3FFFL) == 0) {
+      segment.set(ValueLayout.JAVA_BYTE, offset, (byte) ((value & 0x7F) | 0x80));
+      segment.set(ValueLayout.JAVA_BYTE, offset + 1, (byte) (value >>> 7));
+      return 2;
+    }
+
+    // General case
+    int bytesWritten = 0;
+    while ((value & ~0x7FL) != 0) {
+      segment.set(ValueLayout.JAVA_BYTE, offset + bytesWritten, (byte) ((value & 0x7F) | 0x80));
+      value >>>= 7;
+      bytesWritten++;
+    }
+    segment.set(ValueLayout.JAVA_BYTE, offset + bytesWritten, (byte) value);
+    return bytesWritten + 1;
+  }
+
+  /**
+   * Read the encoded width (number of bytes) of a delta-encoded value
+   * at the given offset in a MemorySegment.
+   * Equivalent to {@link #deltaLength} but uses long offset for large segments.
+   *
+   * @param segment the MemorySegment
+   * @param offset  the byte offset
+   * @return the number of bytes this encoded value occupies
+   */
+  public static int readDeltaEncodedWidth(MemorySegment segment, long offset) {
+    byte first = segment.get(ValueLayout.JAVA_BYTE, offset);
+    if (first == NULL_MARKER) {
+      return 1;
+    }
+    return readVarintWidth(segment, offset);
+  }
+
+  /**
+   * Read the byte width of a varint at the given offset.
+   * Scans continuation bits without decoding the value.
+   *
+   * @param segment the MemorySegment
+   * @param offset  the byte offset
+   * @return number of bytes the varint occupies
+   */
+  public static int readVarintWidth(MemorySegment segment, long offset) {
+    int len = 0;
+    while ((segment.get(ValueLayout.JAVA_BYTE, offset + len) & 0x80) != 0) {
+      len++;
+    }
+    return len + 1;
+  }
+
+  /**
+   * Read the byte width of a signed varint at the given offset.
+   * Signed values use zigzag encoding, but the byte-level representation
+   * is the same as unsigned varint.
+   *
+   * @param segment the MemorySegment
+   * @param offset  the byte offset
+   * @return number of bytes the signed varint occupies
+   */
+  public static int readSignedVarintWidth(MemorySegment segment, long offset) {
+    return readVarintWidth(segment, offset);
+  }
+
+  // ==================== RAW-COPY FIELD RESIZE ====================
+
+  /**
+   * Encoder for a single field during raw-copy resize.
+   * Called to write the new value of the changed field into the target segment.
+   */
+  @FunctionalInterface
+  public interface FieldEncoder {
+    /**
+     * Encode a field value into the target segment at the given absolute offset.
+     *
+     * @param target the target MemorySegment
+     * @param offset absolute byte offset to write at
+     * @return number of bytes written
+     */
+    int encode(MemorySegment target, long offset);
+  }
+
+  /**
+   * Resize a single field in a record by raw-copying unchanged fields and re-encoding
+   * only the changed field. This avoids the full unbind→re-serialize round-trip.
+   *
+   * 
Uses three bulk {@link MemorySegment#copy} calls (AVX/SSE intrinsics on x86)
+   * for unchanged regions, plus one {@link FieldEncoder#encode} call for the changed field.
+   * The offset table is patched in-place to reflect the new field sizes.
+   *
+   * 
Record Layout Assumed

+   * 
+   * [nodeKind: 1 byte][offsetTable: fieldCount × 1 byte][data region: varint fields]
+   * 

+   *
+   * @param srcPage        source page MemorySegment
+   * @param srcRecordBase  absolute offset of the source record start
+   * @param srcRecordLen   byte length of the source record (excluding DeweyID trailer)
+   * @param fieldCount     number of fields in the offset table
+   * @param fieldIndex     index of the field to change (0 to fieldCount-1)
+   * @param dstPage        destination page MemorySegment (may be same as srcPage for different offset)
+   * @param dstRecordBase  absolute offset to write the new record at
+   * @param encoder        encodes the new field value
+   * @return total bytes written for the new record (excluding DeweyID trailer)
+   */
+  public static int resizeField(
+      final MemorySegment srcPage, final long srcRecordBase, final int srcRecordLen,
+      final int fieldCount, final int fieldIndex,
+      final MemorySegment dstPage, final long dstRecordBase,
+      final FieldEncoder encoder) {
+
+    // Offset table starts at recordBase + 1 (after nodeKind byte)
+    final long srcOffsetTable = srcRecordBase + 1;
+    final long srcDataRegion = srcRecordBase + 1 + fieldCount;
+
+    // Read old field offsets from source offset table
+    final int oldFieldStart = srcPage.get(ValueLayout.JAVA_BYTE, srcOffsetTable + fieldIndex) & 0xFF;
+    final int oldFieldEnd;
+    if (fieldIndex + 1 < fieldCount) {
+      oldFieldEnd = srcPage.get(ValueLayout.JAVA_BYTE, srcOffsetTable + fieldIndex + 1) & 0xFF;
+    } else {
+      // Last field: ends at record boundary
+      oldFieldEnd = srcRecordLen - 1 - fieldCount; // subtract header (1) + offset table (fieldCount)
+    }
+    final int oldFieldLen = oldFieldEnd - oldFieldStart;
+
+    // --- Step 1: Copy nodeKind byte ---
+    dstPage.set(ValueLayout.JAVA_BYTE, dstRecordBase,
+        srcPage.get(ValueLayout.JAVA_BYTE, srcRecordBase));
+
+    // --- Step 2: Reserve space for offset table (written after field data) ---
+    final long dstOffsetTable = dstRecordBase + 1;
+    final long dstDataRegion = dstRecordBase + 1 + fieldCount;
+
+    // --- Step 3: Copy data before changed field ---
+    long dstPos = dstDataRegion;
+    if (oldFieldStart > 0) {
+      MemorySegment.copy(srcPage, srcDataRegion, dstPage, dstDataRegion, oldFieldStart);
+      dstPos += oldFieldStart;
+    }
+
+    // --- Step 4: Encode the changed field ---
+    final int newFieldLen = encoder.encode(dstPage, dstPos);
+    dstPos += newFieldLen;
+
+    // --- Step 5: Copy data after changed field ---
+    final int dataRegionLen = srcRecordLen - 1 - fieldCount;
+    final int tailLen = dataRegionLen - oldFieldEnd;
+    if (tailLen > 0) {
+      MemorySegment.copy(srcPage, srcDataRegion + oldFieldEnd, dstPage, dstPos, tailLen);
+      dstPos += tailLen;
+    }
+
+    // --- Step 6: Patch offset table ---
+    final int widthDelta = newFieldLen - oldFieldLen;
+
+    // Copy offsets for fields before the changed field (unchanged)
+    for (int i = 0; i < fieldIndex; i++) {
+      dstPage.set(ValueLayout.JAVA_BYTE, dstOffsetTable + i,
+          srcPage.get(ValueLayout.JAVA_BYTE, srcOffsetTable + i));
+    }
+
+    // Changed field offset is the same as old (data before it hasn't moved)
+    dstPage.set(ValueLayout.JAVA_BYTE, dstOffsetTable + fieldIndex, (byte) oldFieldStart);
+
+    // Shift offsets for fields after the changed field
+    for (int i = fieldIndex + 1; i < fieldCount; i++) {
+      final int oldOff = srcPage.get(ValueLayout.JAVA_BYTE, srcOffsetTable + i) & 0xFF;
+      dstPage.set(ValueLayout.JAVA_BYTE, dstOffsetTable + i, (byte) (oldOff + widthDelta));
+    }
+
+    return (int) (dstPos - dstRecordBase);
+  }
+
+  // ==================== LONG-OFFSET SEGMENT DECODE METHODS ====================
+
+  /**
+   * Decode a delta-encoded key from MemorySegment using long offset.
+   * ZERO ALLOCATION.
+   *
+   * @param segment the MemorySegment
+   * @param offset  the byte offset (long for large pages)
+   * @param baseKey the reference key for delta calculation
+   * @return the decoded absolute key
+   */
+  public static long decodeDeltaFromSegment(MemorySegment segment, long offset, long baseKey) {
+    long zigzag = readVarLongFromSegment(segment, offset);
+
+    if (zigzag == NULL_MARKER) {
+      return NULL_KEY;
+    }
+
+    long delta = zigzagDecode(zigzag - 1);
+    return baseKey + delta;
+  }
+
+  /**
+   * Read unsigned varint from MemorySegment using long offset.
+   * ZERO ALLOCATION.
+   *
+   * @param segment the MemorySegment
+   * @param offset  the byte offset (long)
+   * @return the decoded unsigned long value
+   */
+  public static long readVarLongFromSegment(MemorySegment segment, long offset) {
+    byte b = segment.get(ValueLayout.JAVA_BYTE, offset);
+
+    if ((b & 0x80) == 0) {
+      return b;
+    }
+
+    long result = b & 0x7F;
+    b = segment.get(ValueLayout.JAVA_BYTE, offset + 1);
+
+    if ((b & 0x80) == 0) {
+      return result | ((long) b << 7);
+    }
+
+    result |= (long) (b & 0x7F) << 7;
+    long pos = offset + 2;
+    int shift = 14;
+    do {
+      b = segment.get(ValueLayout.JAVA_BYTE, pos++);
+      result |= (long) (b & 0x7F) << shift;
+      shift += 7;
+
+      if (shift > 70) {
+        throw new IllegalStateException("Varint too long (more than 10 bytes)");
+      }
+    } while ((b & 0x80) != 0);
+
+    return result;
+  }
+
+  /**
+   * Read signed integer (zigzag decoded) from MemorySegment using long offset.
+   * ZERO ALLOCATION.
+   *
+   * @param segment the MemorySegment
+   * @param offset  the byte offset (long)
+   * @return the decoded signed integer value
+   */
+  public static int decodeSignedFromSegment(MemorySegment segment, long offset) {
+    long zigzag = readVarLongFromSegment(segment, offset);
+    return (int) zigzagDecode(zigzag);
+  }
+
+  /**
+   * Read signed long (zigzag decoded) from MemorySegment using long offset.
+   * ZERO ALLOCATION.
+   *
+   * @param segment the MemorySegment
+   * @param offset  the byte offset (long)
+   * @return the decoded signed long value
+   */
+  public static long decodeSignedLongFromSegment(MemorySegment segment, long offset) {
+    long zigzag = readVarLongFromSegment(segment, offset);
+    return zigzagDecode(zigzag);
+  }
 }
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/MemorySegmentBytesOut.java b/bundles/sirix-core/src/main/java/io/sirix/node/MemorySegmentBytesOut.java
index a5c5fbc01..4d8bc728c 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/MemorySegmentBytesOut.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/MemorySegmentBytesOut.java
@@ -4,8 +4,6 @@
 import java.lang.foreign.Arena;
 import java.lang.foreign.MemorySegment;
 import java.math.BigInteger;
-import java.nio.ByteBuffer;
-import java.nio.ByteOrder;
 import net.openhft.hashing.LongHashFunction;
 
 /**
@@ -172,22 +170,6 @@ public BytesOut writeSegment(MemorySegment source, long sourceOff
     return this;
   }
 
-  @Override
-  public BytesOut write(long position, ByteBuffer buffer, int bufferPosition, int length) {
-    long oldPos = growingSegment.position();
-    growingSegment.setPosition(position);
-
-    byte[] temp = new byte[length];
-    int oldBufferPos = buffer.position();
-    buffer.position(bufferPosition);
-    buffer.get(temp);
-    buffer.position(oldBufferPos);
-
-    write(temp);
-    growingSegment.setPosition(oldPos);
-    return this;
-  }
-
   @Override
   public long position() {
     return growingSegment.position();
@@ -225,7 +207,9 @@ public long hashDirect(LongHashFunction hashFunction) {
     if (backingArray != null) {
       return hashFunction.hashBytes(backingArray, 0, growingSegment.getUsedSize());
     }
-    return hashFunction.hashBytes(growingSegment.getUsedSegment().asByteBuffer());
+    // Off-heap: hash directly from native address — no legacy ByteBuffer
+    final MemorySegment seg = growingSegment.getUsedSegment();
+    return hashFunction.hashMemory(seg.address(), seg.byteSize());
   }
 
   @Override
@@ -246,9 +230,7 @@ public BytesOut clear() {
 
   @Override
   public Object underlyingObject() {
-    // Return a ByteBuffer view for compatibility with FileChannelWriter
-    // Set native byte order to match FileChannelWriter expectations
-    return growingSegment.getUsedSegment().asByteBuffer().order(ByteOrder.nativeOrder());
+    return growingSegment.getUsedSegment();
   }
 
   @Override
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/NodeKind.java b/bundles/sirix-core/src/main/java/io/sirix/node/NodeKind.java
index 91030adb5..cf539bb73 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/NodeKind.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/NodeKind.java
@@ -44,9 +44,6 @@
 import io.sirix.node.delegates.NodeDelegate;
 import io.sirix.node.delegates.StructNodeDelegate;
 import io.sirix.node.delegates.ValueNodeDelegate;
-import io.sirix.node.layout.NodeKindLayout;
-import io.sirix.node.layout.NodeKindLayouts;
-import io.sirix.node.layout.StructuralField;
 import io.sirix.node.interfaces.DataRecord;
 import io.sirix.node.interfaces.DeweyIdSerializer;
 import io.sirix.node.interfaces.StructNode;
@@ -357,13 +354,10 @@ public void serialize(final BytesOut sink, final DataRecord record,
       final long childCount = config.storeChildCount()
           ? DeltaVarIntCodec.decodeSigned(source)
           : 0;
-      final long hash;
       final long descendantCount;
       if (config.hashType != HashType.NONE) {
-        hash = source.readLong();
         descendantCount = DeltaVarIntCodec.decodeSigned(source);
       } else {
-        hash = 0;
         descendantCount = 0;
       }
 
@@ -372,7 +366,7 @@ public void serialize(final BytesOut sink, final DataRecord record,
       source.read(value, 0, value.length);
 
       return new PINode(recordID, parentKey, previousRevision, lastModifiedRevision, rightSiblingKey, leftSiblingKey,
-          firstChildKey, lastChildKey, childCount, descendantCount, hash, pathNodeKey, prefixKey, localNameKey, uriKey,
+          firstChildKey, lastChildKey, childCount, descendantCount, 0, pathNodeKey, prefixKey, localNameKey, uriKey,
           value, isCompressed, resourceConfiguration.nodeHashFunction, deweyID, new QNm(""));
     }
 
@@ -399,7 +393,6 @@ public void serialize(final BytesOut sink, final DataRecord record,
         DeltaVarIntCodec.encodeSigned(sink, (int) node.getChildCount());
       }
       if (config.hashType != HashType.NONE) {
-        writeHash(sink, node.getHash());
         DeltaVarIntCodec.encodeSigned(sink, (int) node.getDescendantCount());
       }
 
@@ -1104,16 +1097,13 @@ public void serializeDeweyID(BytesOut sink, byte[] deweyID, byte[] nextDeweyI
       // LAZY FIELDS (metadata + value)
       int prevRev = DeltaVarIntCodec.decodeSigned(source);
       int lastModRev = DeltaVarIntCodec.decodeSigned(source);
-      long hash = resourceConfiguration.hashType != HashType.NONE
-          ? source.readLong()
-          : 0;
       // Compression flag (1 byte: 0 = none, 1 = FSST)
       boolean isCompressed = source.readByte() == 1;
       int length = DeltaVarIntCodec.decodeSigned(source);
       byte[] value = new byte[length];
       source.read(value);
       // Note: fsstSymbolTable will be set by the page after deserialization if needed
-      return new ObjectStringNode(recordID, parentKey, prevRev, lastModRev, hash, value,
+      return new ObjectStringNode(recordID, parentKey, prevRev, lastModRev, 0, value,
           resourceConfiguration.nodeHashFunction, deweyID, isCompressed, null);
     }
 
@@ -1127,9 +1117,6 @@ public void serialize(final BytesOut sink, final DataRecord record,
       // LAZY FIELDS (metadata + value)
       DeltaVarIntCodec.encodeSigned(sink, node.getPreviousRevisionNumber());
       DeltaVarIntCodec.encodeSigned(sink, node.getLastModifiedRevisionNumber());
-      if (resourceConfiguration.hashType != HashType.NONE) {
-        sink.writeLong(node.getHash());
-      }
       // Compression flag (1 byte: 0 = none, 1 = FSST)
       sink.writeByte(node.isCompressed()
           ? (byte) 1
@@ -1165,10 +1152,7 @@ public void serializeDeweyID(BytesOut sink, byte[] deweyID, byte[] nextDeweyI
       int prevRev = DeltaVarIntCodec.decodeSigned(source);
       int lastModRev = DeltaVarIntCodec.decodeSigned(source);
       boolean value = source.readBoolean();
-      long hash = resourceConfiguration.hashType != HashType.NONE
-          ? source.readLong()
-          : 0;
-      return new ObjectBooleanNode(recordID, parentKey, prevRev, lastModRev, hash, value,
+      return new ObjectBooleanNode(recordID, parentKey, prevRev, lastModRev, 0, value,
           resourceConfiguration.nodeHashFunction, deweyID);
     }
 
@@ -1183,9 +1167,6 @@ public void serialize(final BytesOut sink, final DataRecord record,
       DeltaVarIntCodec.encodeSigned(sink, node.getPreviousRevisionNumber());
       DeltaVarIntCodec.encodeSigned(sink, node.getLastModifiedRevisionNumber());
       sink.writeBoolean(node.getValue());
-      if (resourceConfiguration.hashType != HashType.NONE) {
-        sink.writeLong(node.getHash());
-      }
     }
 
     @Override
@@ -1212,11 +1193,8 @@ public void serializeDeweyID(BytesOut sink, byte[] deweyID, byte[] nextDeweyI
       // LAZY FIELDS (metadata + value)
       int prevRev = DeltaVarIntCodec.decodeSigned(source);
       int lastModRev = DeltaVarIntCodec.decodeSigned(source);
-      long hash = resourceConfiguration.hashType != HashType.NONE
-          ? source.readLong()
-          : 0;
       Number value = deserializeNumber(source);
-      return new ObjectNumberNode(recordID, parentKey, prevRev, lastModRev, hash, value,
+      return new ObjectNumberNode(recordID, parentKey, prevRev, lastModRev, 0, value,
           resourceConfiguration.nodeHashFunction, deweyID);
     }
 
@@ -1230,9 +1208,6 @@ public void serialize(final BytesOut sink, final DataRecord record,
       // LAZY FIELDS (metadata + value)
       DeltaVarIntCodec.encodeSigned(sink, node.getPreviousRevisionNumber());
       DeltaVarIntCodec.encodeSigned(sink, node.getLastModifiedRevisionNumber());
-      if (resourceConfiguration.hashType != HashType.NONE) {
-        sink.writeLong(node.getHash());
-      }
       serializeNumber(node.getValue(), sink);
     }
 
@@ -1259,10 +1234,7 @@ public void serializeDeweyID(BytesOut sink, byte[] deweyID, byte[] nextDeweyI
       // LAZY FIELDS (metadata)
       int prevRev = DeltaVarIntCodec.decodeSigned(source);
       int lastModRev = DeltaVarIntCodec.decodeSigned(source);
-      long hash = resourceConfiguration.hashType != HashType.NONE
-          ? source.readLong()
-          : 0;
-      return new ObjectNullNode(recordID, parentKey, prevRev, lastModRev, hash, resourceConfiguration.nodeHashFunction,
+      return new ObjectNullNode(recordID, parentKey, prevRev, lastModRev, 0, resourceConfiguration.nodeHashFunction,
           deweyID);
     }
 
@@ -1276,9 +1248,6 @@ public void serialize(final BytesOut sink, final DataRecord record,
       // LAZY FIELDS (metadata)
       DeltaVarIntCodec.encodeSigned(sink, node.getPreviousRevisionNumber());
       DeltaVarIntCodec.encodeSigned(sink, node.getLastModifiedRevisionNumber());
-      if (resourceConfiguration.hashType != HashType.NONE) {
-        sink.writeLong(node.getHash());
-      }
     }
 
     @Override
@@ -1307,16 +1276,13 @@ public void serializeDeweyID(BytesOut sink, byte[] deweyID, byte[] nextDeweyI
       // LAZY FIELDS (metadata + value)
       int prevRev = DeltaVarIntCodec.decodeSigned(source);
       int lastModRev = DeltaVarIntCodec.decodeSigned(source);
-      long hash = resourceConfiguration.hashType != HashType.NONE
-          ? source.readLong()
-          : 0;
       // Compression flag (1 byte: 0 = none, 1 = FSST)
       boolean isCompressed = source.readByte() == 1;
       int length = DeltaVarIntCodec.decodeSigned(source);
       byte[] value = new byte[length];
       source.read(value);
       // Note: fsstSymbolTable will be set by the page after deserialization if needed
-      return new StringNode(recordID, parentKey, prevRev, lastModRev, rightSiblingKey, leftSiblingKey, hash, value,
+      return new StringNode(recordID, parentKey, prevRev, lastModRev, rightSiblingKey, leftSiblingKey, 0, value,
           resourceConfiguration.nodeHashFunction, deweyID, isCompressed, null);
     }
 
@@ -1332,9 +1298,6 @@ public void serialize(final BytesOut sink, final DataRecord record,
       // LAZY FIELDS (metadata + value)
       DeltaVarIntCodec.encodeSigned(sink, node.getPreviousRevisionNumber());
       DeltaVarIntCodec.encodeSigned(sink, node.getLastModifiedRevisionNumber());
-      if (resourceConfiguration.hashType != HashType.NONE) {
-        sink.writeLong(node.getHash());
-      }
       // Compression flag (1 byte: 0 = none, 1 = FSST)
       sink.writeByte(node.isCompressed()
           ? (byte) 1
@@ -1372,10 +1335,7 @@ public void serializeDeweyID(BytesOut sink, byte[] deweyID, byte[] nextDeweyI
       int prevRev = DeltaVarIntCodec.decodeSigned(source);
       int lastModRev = DeltaVarIntCodec.decodeSigned(source);
       boolean value = source.readBoolean();
-      long hash = resourceConfiguration.hashType != HashType.NONE
-          ? source.readLong()
-          : 0;
-      return new BooleanNode(recordID, parentKey, prevRev, lastModRev, rightSiblingKey, leftSiblingKey, hash, value,
+      return new BooleanNode(recordID, parentKey, prevRev, lastModRev, rightSiblingKey, leftSiblingKey, 0, value,
           resourceConfiguration.nodeHashFunction, deweyID);
     }
 
@@ -1392,9 +1352,6 @@ public void serialize(final BytesOut sink, final DataRecord record,
       DeltaVarIntCodec.encodeSigned(sink, node.getPreviousRevisionNumber());
       DeltaVarIntCodec.encodeSigned(sink, node.getLastModifiedRevisionNumber());
       sink.writeBoolean(node.getValue());
-      if (resourceConfiguration.hashType != HashType.NONE) {
-        sink.writeLong(node.getHash());
-      }
     }
 
     @Override
@@ -1423,11 +1380,8 @@ public void serializeDeweyID(BytesOut sink, byte[] deweyID, byte[] nextDeweyI
       // LAZY FIELDS (metadata + value)
       int prevRev = DeltaVarIntCodec.decodeSigned(source);
       int lastModRev = DeltaVarIntCodec.decodeSigned(source);
-      long hash = resourceConfiguration.hashType != HashType.NONE
-          ? source.readLong()
-          : 0;
       Number value = deserializeNumber(source);
-      return new NumberNode(recordID, parentKey, prevRev, lastModRev, rightSiblingKey, leftSiblingKey, hash, value,
+      return new NumberNode(recordID, parentKey, prevRev, lastModRev, rightSiblingKey, leftSiblingKey, 0, value,
           resourceConfiguration.nodeHashFunction, deweyID);
     }
 
@@ -1443,9 +1397,6 @@ public void serialize(final BytesOut sink, final DataRecord record,
       // LAZY FIELDS (metadata + value)
       DeltaVarIntCodec.encodeSigned(sink, node.getPreviousRevisionNumber());
       DeltaVarIntCodec.encodeSigned(sink, node.getLastModifiedRevisionNumber());
-      if (resourceConfiguration.hashType != HashType.NONE) {
-        sink.writeLong(node.getHash());
-      }
       serializeNumber(node.getValue(), sink);
     }
 
@@ -1474,10 +1425,7 @@ public void serializeDeweyID(BytesOut sink, byte[] deweyID, byte[] nextDeweyI
       // LAZY FIELDS (metadata)
       int prevRev = DeltaVarIntCodec.decodeSigned(source);
       int lastModRev = DeltaVarIntCodec.decodeSigned(source);
-      long hash = resourceConfiguration.hashType != HashType.NONE
-          ? source.readLong()
-          : 0;
-      return new NullNode(recordID, parentKey, prevRev, lastModRev, rightSiblingKey, leftSiblingKey, hash,
+      return new NullNode(recordID, parentKey, prevRev, lastModRev, rightSiblingKey, leftSiblingKey, 0,
           resourceConfiguration.nodeHashFunction, deweyID);
     }
 
@@ -1493,9 +1441,6 @@ public void serialize(final BytesOut sink, final DataRecord record,
       // LAZY FIELDS (metadata)
       DeltaVarIntCodec.encodeSigned(sink, node.getPreviousRevisionNumber());
       DeltaVarIntCodec.encodeSigned(sink, node.getLastModifiedRevisionNumber());
-      if (resourceConfiguration.hashType != HashType.NONE) {
-        sink.writeLong(node.getHash());
-      }
     }
 
     @Override
@@ -1720,25 +1665,6 @@ public byte getId() {
     return id;
   }
 
-  /**
-   * Fixed-slot layout contract for this node kind.
-   */
-  public NodeKindLayout layoutDescriptor() {
-    return NodeKindLayouts.layoutFor(this);
-  }
-
-  public boolean hasFixedSlotLayout() {
-    return layoutDescriptor().isFixedSlotSupported();
-  }
-
-  public int fixedSlotSizeInBytes() {
-    return layoutDescriptor().fixedSlotSizeInBytes();
-  }
-
-  public int offsetOfOrMinusOne(final StructuralField field) {
-    return layoutDescriptor().offsetOfOrMinusOne(field);
-  }
-
   /**
    * Public method to get the related node based on the identifier.
    *
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/NullNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/NullNode.java
index a07aa6017..320fbc92d 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/NullNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/NullNode.java
@@ -29,7 +29,6 @@
 import io.sirix.node.interfaces.immutable.ImmutableNode;
 import io.sirix.settings.Fixed;
 
-import java.nio.ByteBuffer;
 
 import static java.util.Objects.requireNonNull;
 
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/PooledBytesOut.java b/bundles/sirix-core/src/main/java/io/sirix/node/PooledBytesOut.java
index 5500f9cef..7d871b995 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/PooledBytesOut.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/PooledBytesOut.java
@@ -5,7 +5,7 @@
 import java.lang.foreign.ValueLayout;
 import java.math.BigDecimal;
 import java.math.BigInteger;
-import java.nio.ByteBuffer;
+import net.openhft.hashing.LongHashFunction;
 
 /**
  * A BytesOut implementation backed by a PooledGrowingSegment.
@@ -172,22 +172,6 @@ public BytesOut writeSegment(MemorySegment source, long sourceOff
     return this;
   }
 
-  @Override
-  public BytesOut write(long position, ByteBuffer buffer, int bufferPosition, int length) {
-    long oldPos = segment.position();
-    segment.position(position);
-
-    byte[] temp = new byte[length];
-    int oldBufferPos = buffer.position();
-    buffer.position(bufferPosition);
-    buffer.get(temp);
-    buffer.position(oldBufferPos);
-
-    write(temp);
-    segment.position(oldPos);
-    return this;
-  }
-
   @Override
   public long position() {
     return segment.position();
@@ -226,6 +210,22 @@ public byte[] toByteArray() {
     return result;
   }
 
+  @Override
+  public long hashDirect(LongHashFunction hashFunction) {
+    final long len = segment.position();
+    if (len == 0) {
+      return hashFunction.hashBytes(new byte[0]);
+    }
+    final MemorySegment seg = segment.getCurrentSegment();
+    final Object heapBase = seg.heapBase().orElse(null);
+    if (heapBase instanceof byte[] backingArray) {
+      // Heap-backed: hash directly from backing array — zero allocation
+      return hashFunction.hashBytes(backingArray, 0, (int) len);
+    }
+    // Native segment: hash directly from native address — zero allocation
+    return hashFunction.hashMemory(seg.address(), len);
+  }
+
   @Override
   public BytesIn bytesForRead() {
     return new MemorySegmentBytesIn(segment.getWrittenSlice());
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/delegates/NodeDelegate.java b/bundles/sirix-core/src/main/java/io/sirix/node/delegates/NodeDelegate.java
index 89571a246..d8f5cc905 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/delegates/NodeDelegate.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/delegates/NodeDelegate.java
@@ -246,6 +246,13 @@ public void setLastModifiedRevision(int lastModifiedRevision) {
   @Override
   public void setDeweyID(final SirixDeweyID id) {
     sirixDeweyID = id;
+    deweyIDData = null;
+  }
+
+  @Override
+  public void setDeweyIDBytes(final byte[] bytes) {
+    this.deweyIDData = bytes;
+    this.sirixDeweyID = null;
   }
 
   @Override
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableArrayNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableArrayNode.java
index aa2205258..8a77c2497 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableArrayNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableArrayNode.java
@@ -8,7 +8,6 @@
 import io.sirix.node.BytesOut;
 import io.sirix.node.json.ArrayNode;
 
-import java.nio.ByteBuffer;
 
 import static java.util.Objects.requireNonNull;
 
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableBooleanNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableBooleanNode.java
index 9d215e06f..d2b664ac8 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableBooleanNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableBooleanNode.java
@@ -9,7 +9,6 @@
 import io.sirix.node.json.StringNode;
 import io.sirix.node.xml.TextNode;
 
-import java.nio.ByteBuffer;
 
 import static java.util.Objects.requireNonNull;
 
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableJsonDocumentRootNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableJsonDocumentRootNode.java
index f4fee0020..716b3e676 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableJsonDocumentRootNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableJsonDocumentRootNode.java
@@ -7,7 +7,6 @@
 import io.sirix.node.BytesOut;
 import io.sirix.node.json.JsonDocumentRootNode;
 
-import java.nio.ByteBuffer;
 
 import static java.util.Objects.requireNonNull;
 
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableNullNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableNullNode.java
index 41564abd4..462578428 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableNullNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableNullNode.java
@@ -8,7 +8,6 @@
 import io.sirix.node.BytesOut;
 import io.sirix.node.json.NullNode;
 
-import java.nio.ByteBuffer;
 
 import static java.util.Objects.requireNonNull;
 
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableNumberNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableNumberNode.java
index caaa2dc7c..ded653ba2 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableNumberNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableNumberNode.java
@@ -7,7 +7,6 @@
 import io.sirix.node.BytesOut;
 import io.sirix.node.json.NumberNode;
 
-import java.nio.ByteBuffer;
 
 import static java.util.Objects.requireNonNull;
 
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableObjectBooleanNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableObjectBooleanNode.java
index e59558f23..292bfeec9 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableObjectBooleanNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableObjectBooleanNode.java
@@ -9,7 +9,6 @@
 import io.sirix.node.json.StringNode;
 import io.sirix.node.xml.TextNode;
 
-import java.nio.ByteBuffer;
 
 import static java.util.Objects.requireNonNull;
 
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableObjectKeyNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableObjectKeyNode.java
index 7f25e5948..d83c4c582 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableObjectKeyNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableObjectKeyNode.java
@@ -10,7 +10,6 @@
 import io.sirix.node.json.ObjectNode;
 import io.sirix.node.BytesOut;
 
-import java.nio.ByteBuffer;
 
 import static java.util.Objects.requireNonNull;
 
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableObjectNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableObjectNode.java
index a1d098866..02789dd86 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableObjectNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableObjectNode.java
@@ -7,7 +7,6 @@
 import io.sirix.node.BytesOut;
 import io.sirix.node.json.ObjectNode;
 
-import java.nio.ByteBuffer;
 
 import static java.util.Objects.requireNonNull;
 
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableObjectNullNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableObjectNullNode.java
index bc9c50eea..63712c80f 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableObjectNullNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableObjectNullNode.java
@@ -8,7 +8,6 @@
 import io.sirix.node.BytesOut;
 import io.sirix.node.json.ObjectNullNode;
 
-import java.nio.ByteBuffer;
 
 import static java.util.Objects.requireNonNull;
 
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableObjectNumberNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableObjectNumberNode.java
index 4884471b0..1b80730c8 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableObjectNumberNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableObjectNumberNode.java
@@ -8,7 +8,6 @@
 import io.sirix.node.json.NumberNode;
 import io.sirix.node.json.ObjectNumberNode;
 
-import java.nio.ByteBuffer;
 
 import static java.util.Objects.requireNonNull;
 
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableObjectStringNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableObjectStringNode.java
index faa3fff3e..e422eb27b 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableObjectStringNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableObjectStringNode.java
@@ -11,7 +11,6 @@
 import org.checkerframework.checker.nullness.qual.Nullable;
 import io.sirix.node.json.ObjectStringNode;
 
-import java.nio.ByteBuffer;
 
 import static java.util.Objects.requireNonNull;
 
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableStringNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableStringNode.java
index f2f6da70c..c79f9a726 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableStringNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/json/ImmutableStringNode.java
@@ -12,7 +12,6 @@
 import io.sirix.node.json.StringNode;
 import io.sirix.node.xml.TextNode;
 
-import java.nio.ByteBuffer;
 
 import static java.util.Objects.requireNonNull;
 
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutableAttributeNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutableAttributeNode.java
index 839b418d4..9dd14bd4c 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutableAttributeNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutableAttributeNode.java
@@ -15,7 +15,6 @@
 import org.checkerframework.checker.nullness.qual.Nullable;
 import io.sirix.node.xml.AttributeNode;
 
-import java.nio.ByteBuffer;
 
 import static java.util.Objects.requireNonNull;
 
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutableComment.java b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutableComment.java
index 546b39099..483c844ad 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutableComment.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutableComment.java
@@ -12,7 +12,6 @@
 import org.checkerframework.checker.nullness.qual.Nullable;
 import io.sirix.node.xml.CommentNode;
 
-import java.nio.ByteBuffer;
 
 import static java.util.Objects.requireNonNull;
 
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutableElement.java b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutableElement.java
index ac1f32aaf..406cb2c7d 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutableElement.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutableElement.java
@@ -13,7 +13,6 @@
 import io.brackit.query.atomic.QNm;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
-import java.nio.ByteBuffer;
 
 import static java.util.Objects.requireNonNull;
 
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutableNamespace.java b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutableNamespace.java
index b85c6970a..332e6fb7e 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutableNamespace.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutableNamespace.java
@@ -12,7 +12,6 @@
 import org.checkerframework.checker.nullness.qual.Nullable;
 import io.sirix.node.xml.NamespaceNode;
 
-import java.nio.ByteBuffer;
 
 import static java.util.Objects.requireNonNull;
 
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutablePI.java b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutablePI.java
index 9e14d90a2..2ab706997 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutablePI.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutablePI.java
@@ -14,7 +14,6 @@
 import io.brackit.query.atomic.QNm;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
-import java.nio.ByteBuffer;
 
 import static java.util.Objects.requireNonNull;
 
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutableText.java b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutableText.java
index e0b5c7645..e87755628 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutableText.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutableText.java
@@ -12,7 +12,6 @@
 import org.checkerframework.checker.nullness.qual.Nullable;
 import io.sirix.node.xml.TextNode;
 
-import java.nio.ByteBuffer;
 
 import static java.util.Objects.requireNonNull;
 
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutableXmlDocumentRootNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutableXmlDocumentRootNode.java
index c8076dd5c..60ae4395d 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutableXmlDocumentRootNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/immutable/xml/ImmutableXmlDocumentRootNode.java
@@ -11,7 +11,6 @@
 import io.sirix.node.BytesOut;
 import io.sirix.node.xml.XmlDocumentRootNode;
 
-import java.nio.ByteBuffer;
 
 import static java.util.Objects.requireNonNull;
 
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/interfaces/FlyweightNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/interfaces/FlyweightNode.java
new file mode 100644
index 000000000..32d52ef04
--- /dev/null
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/interfaces/FlyweightNode.java
@@ -0,0 +1,140 @@
+package io.sirix.node.interfaces;
+
+import java.lang.foreign.MemorySegment;
+
+import io.sirix.page.KeyValueLeafPage;
+
+/**
+ * Interface for nodes that support LeanStore-style flyweight binding to a slotted page MemorySegment.
+ *
+ * 
Flyweight nodes can serialize themselves directly to a page heap (with per-record offset tables)
+ * and bind to an existing record in the heap for direct in-place reads/writes without Java object
+ * intermediation.

+ *
+ * 
When bound, all getters/setters operate directly on the page MemorySegment via the offset table.
+ * When unbound, they operate on Java primitive fields (normal mode).

+ */
+public interface FlyweightNode extends DataRecord {
+
+  /**
+   * Serialize this node to the target MemorySegment in the slotted page heap format:
+   * {@code [nodeKind:1][fieldOffsets:N×1byte][varint fields + hash + payload]}.
+   *
+   * 
All Java primitive fields must be materialized before calling this method
+   * (i.e., if the node has lazy fields, they must be parsed first).

+   *
+   * @param target the target MemorySegment to write to
+   * @param offset the absolute byte offset to start writing at
+   * @return the total number of bytes written
+   */
+  int serializeToHeap(MemorySegment target, long offset);
+
+  /**
+   * Bind this node as a flyweight to a page MemorySegment.
+   * After binding, all getters/setters read/write directly to page memory via the offset table.
+   *
+   * @param page       the page MemorySegment
+   * @param recordBase absolute byte offset of this record in the page
+   * @param nodeKey    the node key (for delta decoding)
+   * @param slotIndex  the slot index in the page directory
+   */
+  void bind(MemorySegment page, long recordBase, long nodeKey, int slotIndex);
+
+  /**
+   * Unbind from page memory and materialize all fields into Java primitives.
+   * After unbind, the node operates in primitive mode.
+   */
+  void unbind();
+
+  /**
+   * Clear the page binding without materializing fields.
+   * Use this instead of {@link #unbind()} when all Java fields will be overwritten immediately
+   * after clearing (e.g., in factory bind methods that set all fields via setters).
+   * This avoids the cost of reading each field from the MemorySegment back to Java primitives
+   * only to have them overwritten a moment later.
+   */
+  void clearBinding();
+
+  /**
+   * Check if this node is currently bound to a page MemorySegment.
+   *
+   * @return true if bound (flyweight mode), false if operating on Java primitives
+   */
+  boolean isBound();
+
+  /**
+   * Check if this node is bound to a specific page MemorySegment.
+   * Used to detect cross-page bindings (e.g., bound to complete page but need to rebind to modified page).
+   *
+   * @param page the page MemorySegment to check against
+   * @return true if bound to the specified page
+   */
+  boolean isBoundTo(MemorySegment page);
+
+  /**
+   * Get the slot index this node is currently bound to.
+   * Only valid when {@link #isBound()} is true.
+   *
+   * @return the slot index in the page directory
+   */
+  int getSlotIndex();
+
+  /**
+   * Estimate the serialized size of this record in bytes.
+   * Used to ensure the slotted page has enough space before serialization.
+   * Structural nodes return a small constant; value nodes add their payload size.
+   *
+   * @return conservative upper bound on serialized byte count
+   */
+  default int estimateSerializedSize() {
+    return 256;
+  }
+
+  /**
+   * Check if this node is a write-path singleton managed by a node factory.
+   * Write singletons are rebound per-access and must NOT be stored in records[].
+   *
+   * @return true if this is a factory-managed write singleton
+   */
+  default boolean isWriteSingleton() {
+    return false;
+  }
+
+  /**
+   * Mark this node as a write-path singleton (or clear the mark).
+   *
+   * @param writeSingleton true to mark as write singleton
+   */
+  default void setWriteSingleton(boolean writeSingleton) {
+    // Default no-op; concrete types override
+  }
+
+  /**
+   * Get the owning KeyValueLeafPage for resize-in-place operations.
+   * Only valid when bound ({@link #isBound()} is true).
+   *
+   * @return the owner page, or null if not set
+   */
+  default KeyValueLeafPage getOwnerPage() {
+    return null;
+  }
+
+  /**
+   * Set the owning KeyValueLeafPage.
+   * Called after bind/serializeToHeap so resize-in-place can re-serialize on width changes.
+   *
+   * @param ownerPage the owner page
+   */
+  default void setOwnerPage(KeyValueLeafPage ownerPage) {
+    // Default no-op; concrete write-singleton types override
+  }
+
+  /**
+   * Create an independent snapshot copy of this node with all fields materialized.
+   * The snapshot is a non-singleton DataRecord that can be safely stored in records[]
+   * without singleton aliasing issues.
+   *
+   * @return a new DataRecord copy with all fields set
+   */
+  DataRecord toSnapshot();
+}
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/interfaces/Node.java b/bundles/sirix-core/src/main/java/io/sirix/node/interfaces/Node.java
index 3b2378ea6..d85de2056 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/interfaces/Node.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/interfaces/Node.java
@@ -88,4 +88,17 @@ public interface Node extends ImmutableNode {
    * @param nodeKey the new node key
    */
   void setNodeKey(long nodeKey);
+
+  /**
+   * Set the raw DeweyID bytes without parsing. The full {@link SirixDeweyID} is reconstructed
+   * lazily on the first {@link io.sirix.node.interfaces.immutable.ImmutableNode#getDeweyID()} call.
+   *
+   * 
Unlike {@link #setDeweyID(SirixDeweyID)}, this method does NOT trigger resize on bound
+   * flyweight nodes — it's used during binding when the bytes are already in the page trailer.

+   *
+   * @param deweyIdBytes the raw DeweyID bytes, or null to clear
+   */
+  default void setDeweyIDBytes(final byte[] deweyIdBytes) {
+    setDeweyID(deweyIdBytes != null ? new SirixDeweyID(deweyIdBytes) : null);
+  }
 }
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/interfaces/ReusableNodeProxy.java b/bundles/sirix-core/src/main/java/io/sirix/node/interfaces/ReusableNodeProxy.java
deleted file mode 100644
index 83f3fa959..000000000
--- a/bundles/sirix-core/src/main/java/io/sirix/node/interfaces/ReusableNodeProxy.java
+++ /dev/null
@@ -1,14 +0,0 @@
-package io.sirix.node.interfaces;
-
-/**
- * Marker for transaction-local node proxy instances that may be rebound and reused by node
- * factories.
- *
- * 

- * Records implementing this marker must never be retained as authoritative in-memory page state.
- * Writers persist them directly to slot storage and avoid keeping object references in record
- * arrays.
- * 

- */
-public interface ReusableNodeProxy {
-}
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/interfaces/immutable/ImmutableNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/interfaces/immutable/ImmutableNode.java
index 369701926..e04acde34 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/interfaces/immutable/ImmutableNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/interfaces/immutable/ImmutableNode.java
@@ -6,7 +6,6 @@
 import io.sirix.node.BytesOut;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
-import java.nio.ByteBuffer;
 
 /**
  * An immutable node.
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/json/AbstractBooleanNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/json/AbstractBooleanNode.java
index bbfa69cb0..a98ee6a6b 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/json/AbstractBooleanNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/json/AbstractBooleanNode.java
@@ -74,16 +74,6 @@ public long computeHash(BytesOut bytes) {
          .writeLong(nodeDelegate.getParentKey())
          .writeByte(nodeDelegate.getKind().getId());
 
-    bytes.writeLong(structNodeDelegate.getChildCount())
-         .writeLong(structNodeDelegate.getDescendantCount())
-         .writeLong(structNodeDelegate.getLeftSiblingKey())
-         .writeLong(structNodeDelegate.getRightSiblingKey())
-         .writeLong(structNodeDelegate.getFirstChildKey());
-
-    if (structNodeDelegate.getLastChildKey() != Fixed.INVALID_KEY_FOR_TYPE_CHECK.getStandardProperty()) {
-      bytes.writeLong(structNodeDelegate.getLastChildKey());
-    }
-
     bytes.writeBoolean(boolValue);
 
     return bytes.hashDirect(nodeDelegate.getHashFunction());
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/json/AbstractNullNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/json/AbstractNullNode.java
index 3124b72fa..0b50b36f3 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/json/AbstractNullNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/json/AbstractNullNode.java
@@ -31,13 +31,11 @@
 import io.sirix.node.delegates.NodeDelegate;
 import io.sirix.node.delegates.StructNodeDelegate;
 import io.sirix.node.interfaces.immutable.ImmutableJsonNode;
-import io.sirix.settings.Fixed;
 import io.sirix.node.Bytes;
 import io.sirix.node.BytesOut;
 import io.sirix.node.xml.AbstractStructForwardingNode;
 import org.checkerframework.checker.nullness.qual.NonNull;
 
-import java.nio.ByteBuffer;
 
 public abstract class AbstractNullNode extends AbstractStructForwardingNode implements ImmutableJsonNode {
   private final StructNodeDelegate structNodeDelegate;
@@ -58,16 +56,6 @@ public long computeHash(final BytesOut bytes) {
          .writeLong(nodeDelegate.getParentKey())
          .writeByte(nodeDelegate.getKind().getId());
 
-    bytes.writeLong(structNodeDelegate.getChildCount())
-         .writeLong(structNodeDelegate.getDescendantCount())
-         .writeLong(structNodeDelegate.getLeftSiblingKey())
-         .writeLong(structNodeDelegate.getRightSiblingKey())
-         .writeLong(structNodeDelegate.getFirstChildKey());
-
-    if (structNodeDelegate.getLastChildKey() != Fixed.INVALID_KEY_FOR_TYPE_CHECK.getStandardProperty()) {
-      bytes.writeLong(structNodeDelegate.getLastChildKey());
-    }
-
     return bytes.hashDirect(nodeDelegate.getHashFunction());
   }
 
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/json/AbstractNumberNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/json/AbstractNumberNode.java
index de9c9beff..429d2175b 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/json/AbstractNumberNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/json/AbstractNumberNode.java
@@ -75,16 +75,6 @@ public long computeHash(final BytesOut bytes) {
          .writeLong(nodeDelegate.getParentKey())
          .writeByte(nodeDelegate.getKind().getId());
 
-    bytes.writeLong(structNodeDelegate.getChildCount())
-         .writeLong(structNodeDelegate.getDescendantCount())
-         .writeLong(structNodeDelegate.getLeftSiblingKey())
-         .writeLong(structNodeDelegate.getRightSiblingKey())
-         .writeLong(structNodeDelegate.getFirstChildKey());
-
-    if (structNodeDelegate.getLastChildKey() != Fixed.INVALID_KEY_FOR_TYPE_CHECK.getStandardProperty()) {
-      bytes.writeLong(structNodeDelegate.getLastChildKey());
-    }
-
     switch (number) {
       case Float floatVal -> bytes.writeFloat(floatVal);
       case Double doubleVal -> bytes.writeDouble(doubleVal);
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/json/AbstractStringNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/json/AbstractStringNode.java
index 011e2a6c7..f439c2f27 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/json/AbstractStringNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/json/AbstractStringNode.java
@@ -39,7 +39,6 @@
 import io.sirix.node.xml.AbstractStructForwardingNode;
 import org.checkerframework.checker.nullness.qual.NonNull;
 
-import java.nio.ByteBuffer;
 
 public abstract class AbstractStringNode extends AbstractStructForwardingNode implements ValueNode, ImmutableJsonNode {
 
@@ -64,8 +63,6 @@ public long computeHash(final BytesOut bytes) {
          .writeLong(nodeDelegate.getParentKey())
          .writeByte(nodeDelegate.getKind().getId());
 
-    bytes.writeLong(structNodeDelegate.getLeftSiblingKey()).writeLong(structNodeDelegate.getRightSiblingKey());
-
     bytes.writeUtf8(new String(valueNodeDelegate.getRawValue(), Constants.DEFAULT_ENCODING));
 
     return bytes.hashDirect(nodeDelegate.getHashFunction());
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/json/ArrayNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/json/ArrayNode.java
index bb254cf44..bcf977660 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/json/ArrayNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/json/ArrayNode.java
@@ -43,14 +43,15 @@
 import io.sirix.node.SirixDeweyID;
 
 import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
 import io.sirix.node.immutable.json.ImmutableArrayNode;
-import io.sirix.node.layout.NodeKindLayout;
-import io.sirix.node.layout.SlotLayoutAccessors;
-import io.sirix.node.layout.StructuralField;
+import io.sirix.node.interfaces.FlyweightNode;
 import io.sirix.node.interfaces.Node;
-import io.sirix.node.interfaces.ReusableNodeProxy;
 import io.sirix.node.interfaces.StructNode;
 import io.sirix.node.interfaces.immutable.ImmutableJsonNode;
+import io.sirix.page.KeyValueLeafPage;
+import io.sirix.page.NodeFieldLayout;
+import io.sirix.page.PageLayout;
 import io.sirix.settings.Fixed;
 import net.openhft.hashing.LongHashFunction;
 import org.checkerframework.checker.index.qual.NonNegative;
@@ -60,18 +61,16 @@
 /**
  * JSON Array node.
  *
- * 

- * Uses primitive fields for efficient storage with delta+varint encoding. This eliminates
- * MemorySegment/VarHandle overhead and enables compact serialization.
- * 

+ * 
Uses primitive fields for efficient storage with delta+varint encoding.
+ * This eliminates MemorySegment/VarHandle overhead and enables compact serialization.

  * 
  * @author Johannes Lichtenberger
  */
-public final class ArrayNode implements StructNode, ImmutableJsonNode, ReusableNodeProxy {
+public final class ArrayNode implements StructNode, ImmutableJsonNode, FlyweightNode {
 
   // Node identity (mutable for singleton reuse)
   private long nodeKey;
-
+  
   // Mutable structural fields (updated during tree modifications)
   private long parentKey;
   private long pathNodeKey;
@@ -79,43 +78,78 @@ public final class ArrayNode implements StructNode, ImmutableJsonNode, ReusableN
   private long leftSiblingKey;
   private long firstChildKey;
   private long lastChildKey;
-
+  
   // Mutable revision tracking
   private int previousRevision;
   private int lastModifiedRevision;
-
+  
   // Mutable counters
   private long childCount;
   private long descendantCount;
-
+  
   // Mutable hash
   private long hash;
-
+  
   // Hash function for computing node hashes (mutable for singleton reuse)
   private LongHashFunction hashFunction;
-
+  
   // DeweyID support (lazily parsed)
   private SirixDeweyID sirixDeweyID;
   private byte[] deweyIDBytes;
 
   // Lazy parsing state
   private Object lazySource;
-  private long lazyBaseOffset;
   private long lazyOffset;
   private boolean lazyFieldsParsed;
   private boolean hasHash;
   private boolean storeChildCount;
 
-  // Fixed-slot lazy support
-  private NodeKindLayout fixedSlotLayout;
+  // ==================== FLYWEIGHT BINDING (LeanStore page-direct access) ====================
+
+  /** Page MemorySegment when bound (null = primitive mode). */
+  private MemorySegment page;
+
+  /** Absolute byte offset of this record in the page (after HEAP_START + heapOffset). */
+  private long recordBase;
+
+  /** Absolute byte offset where the data region starts (recordBase + 1 + FIELD_COUNT). */
+  private long dataRegionStart;
+
+  /** Slot index in the page directory (for re-serialization). */
+  private int slotIndex;
+
+  /** True if this node is a factory-managed write singleton (must not be stored in records[]). */
+  private boolean writeSingleton;
+
+  /** Owning page for resize-in-place on varint width changes. */
+  private KeyValueLeafPage ownerPage;
+
+  /** Pre-allocated offset array reused across serializations (zero-alloc hot path). */
+  private final int[] heapOffsets;
+
+  private static final int FIELD_COUNT = NodeFieldLayout.ARRAY_FIELD_COUNT;
 
   /**
-   * Primary constructor with all primitive fields. Used by deserialization
-   * (NodeKind.ARRAY.deserialize).
+   * Constructor for flyweight binding.
+   * All fields except nodeKey and hashFunction will be read from page memory after bind().
+   *
+   * @param nodeKey the node key
+   * @param hashFunction the hash function from resource config
    */
-  public ArrayNode(long nodeKey, long parentKey, long pathNodeKey, int previousRevision, int lastModifiedRevision,
-      long rightSiblingKey, long leftSiblingKey, long firstChildKey, long lastChildKey, long childCount,
-      long descendantCount, long hash, LongHashFunction hashFunction, byte[] deweyID) {
+  public ArrayNode(long nodeKey, LongHashFunction hashFunction) {
+    this.nodeKey = nodeKey;
+    this.hashFunction = hashFunction;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
+
+  /**
+   * Primary constructor with all primitive fields.
+   * Used by deserialization (NodeKind.ARRAY.deserialize).
+   */
+  public ArrayNode(long nodeKey, long parentKey, long pathNodeKey, int previousRevision,
+      int lastModifiedRevision, long rightSiblingKey, long leftSiblingKey, long firstChildKey,
+      long lastChildKey, long childCount, long descendantCount, long hash,
+      LongHashFunction hashFunction, byte[] deweyID) {
     this.nodeKey = nodeKey;
     this.parentKey = parentKey;
     this.pathNodeKey = pathNodeKey;
@@ -131,15 +165,17 @@ public ArrayNode(long nodeKey, long parentKey, long pathNodeKey, int previousRev
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyID;
     this.lazyFieldsParsed = true;
+    this.heapOffsets = new int[FIELD_COUNT];
   }
 
   /**
-   * Constructor with SirixDeweyID instead of byte array. Used by factory methods when creating new
-   * nodes.
+   * Constructor with SirixDeweyID instead of byte array.
+   * Used by factory methods when creating new nodes.
    */
-  public ArrayNode(long nodeKey, long parentKey, long pathNodeKey, int previousRevision, int lastModifiedRevision,
-      long rightSiblingKey, long leftSiblingKey, long firstChildKey, long lastChildKey, long childCount,
-      long descendantCount, long hash, LongHashFunction hashFunction, SirixDeweyID deweyID) {
+  public ArrayNode(long nodeKey, long parentKey, long pathNodeKey, int previousRevision,
+      int lastModifiedRevision, long rightSiblingKey, long leftSiblingKey, long firstChildKey,
+      long lastChildKey, long childCount, long descendantCount, long hash,
+      LongHashFunction hashFunction, SirixDeweyID deweyID) {
     this.nodeKey = nodeKey;
     this.parentKey = parentKey;
     this.pathNodeKey = pathNodeKey;
@@ -155,6 +191,234 @@ public ArrayNode(long nodeKey, long parentKey, long pathNodeKey, int previousRev
     this.hashFunction = hashFunction;
     this.sirixDeweyID = deweyID;
     this.lazyFieldsParsed = true;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
+
+  // ==================== FLYWEIGHT BIND/UNBIND ====================
+
+  /**
+   * Bind this node as a flyweight to a page MemorySegment.
+   * When bound, getters/setters read/write directly to page memory via the offset table.
+   *
+   * @param page       the page MemorySegment
+   * @param recordBase absolute byte offset of this record in the page
+   * @param nodeKey    the node key (for delta decoding)
+   * @param slotIndex  the slot index in the page directory
+   */
+  public void bind(final MemorySegment page, final long recordBase, final long nodeKey,
+      final int slotIndex) {
+    this.page = page;
+    this.recordBase = recordBase;
+    this.nodeKey = nodeKey;
+    this.slotIndex = slotIndex;
+    this.dataRegionStart = recordBase + 1 + FIELD_COUNT;
+    this.lazyFieldsParsed = true; // No lazy state when bound
+    this.lazySource = null;
+  }
+
+  /**
+   * Unbind from page memory and materialize all fields into Java primitives.
+   * After unbind, the node operates in primitive mode.
+   */
+  public void unbind() {
+    if (page == null) {
+      return;
+    }
+    // Materialize all fields from page to Java primitives
+    final long nk = this.nodeKey;
+    this.parentKey = readDeltaField(NodeFieldLayout.ARRAY_PARENT_KEY, nk);
+    this.rightSiblingKey = readDeltaField(NodeFieldLayout.ARRAY_RIGHT_SIB_KEY, nk);
+    this.leftSiblingKey = readDeltaField(NodeFieldLayout.ARRAY_LEFT_SIB_KEY, nk);
+    this.firstChildKey = readDeltaField(NodeFieldLayout.ARRAY_FIRST_CHILD_KEY, nk);
+    this.lastChildKey = readDeltaField(NodeFieldLayout.ARRAY_LAST_CHILD_KEY, nk);
+    this.pathNodeKey = readDeltaField(NodeFieldLayout.ARRAY_PATH_NODE_KEY, nk);
+    this.previousRevision = readSignedField(NodeFieldLayout.ARRAY_PREV_REVISION);
+    this.lastModifiedRevision = readSignedField(NodeFieldLayout.ARRAY_LAST_MOD_REVISION);
+    this.hash = readLongField(NodeFieldLayout.ARRAY_HASH);
+    this.childCount = readSignedLongField(NodeFieldLayout.ARRAY_CHILD_COUNT);
+    this.descendantCount = readSignedLongField(NodeFieldLayout.ARRAY_DESCENDANT_COUNT);
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  @Override
+  public void clearBinding() {
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  /** Check if this node is bound to a page MemorySegment. */
+  public boolean isBound() {
+    return page != null;
+  }
+
+  @Override
+  public boolean isBoundTo(final MemorySegment page) {
+    return this.page == page;
+  }
+
+  @Override
+  public int getSlotIndex() {
+    return slotIndex;
+  }
+
+  // ==================== FLYWEIGHT FIELD READ HELPERS ====================
+
+  private long readDeltaField(final int fieldIndex, final long baseKey) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeDeltaFromSegment(page, dataRegionStart + fieldOff, baseKey);
+  }
+
+  private int readSignedField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeSignedFromSegment(page, dataRegionStart + fieldOff);
+  }
+
+  private long readSignedLongField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeSignedLongFromSegment(page, dataRegionStart + fieldOff);
+  }
+
+  private long readLongField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.readLongFromSegment(page, (int) (dataRegionStart + fieldOff));
+  }
+
+  // ==================== OWNER PAGE (for resize-in-place) ====================
+
+  @Override
+  public KeyValueLeafPage getOwnerPage() {
+    return ownerPage;
+  }
+
+  @Override
+  public void setOwnerPage(final KeyValueLeafPage ownerPage) {
+    this.ownerPage = ownerPage;
+  }
+
+  // ==================== SERIALIZE TO HEAP ====================
+
+  /**
+   * Encode an ArrayNode record directly to a MemorySegment from parameter values.
+   * Static -- reads nothing from any instance. Zero field intermediation.
+   *
+   * @param target          the target MemorySegment (reinterpreted slotted page)
+   * @param offset          absolute byte offset to write at
+   * @param heapOffsets     pre-allocated offset array (reused, FIELD_COUNT elements)
+   * @param nodeKey         the node key (delta base for structural keys)
+   * @param parentKey       the parent node key
+   * @param rightSibKey     the right sibling key
+   * @param leftSibKey      the left sibling key
+   * @param firstChildKey   the first child key
+   * @param lastChildKey    the last child key
+   * @param pathNodeKey     the path node key
+   * @param prevRev         the previous revision number
+   * @param lastModRev      the last modified revision number
+   * @param hash            the hash value
+   * @param childCount      the child count
+   * @param descendantCount the descendant count
+   * @return the total number of bytes written
+   */
+  public static int writeNewRecord(final MemorySegment target, final long offset,
+      final int[] heapOffsets, final long nodeKey,
+      final long parentKey, final long rightSibKey, final long leftSibKey,
+      final long firstChildKey, final long lastChildKey, final long pathNodeKey,
+      final int prevRev, final int lastModRev, final long hash,
+      final long childCount, final long descendantCount) {
+    long pos = offset;
+
+    // Write nodeKind byte
+    target.set(ValueLayout.JAVA_BYTE, pos, NodeKind.ARRAY.getId());
+    pos++;
+
+    // Reserve space for offset table
+    final long offsetTableStart = pos;
+    pos += FIELD_COUNT;
+
+    // Data region start
+    final long dataStart = pos;
+
+    // Field 0: parentKey (delta-varint)
+    heapOffsets[NodeFieldLayout.ARRAY_PARENT_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, parentKey, nodeKey);
+
+    // Field 1: rightSiblingKey (delta-varint)
+    heapOffsets[NodeFieldLayout.ARRAY_RIGHT_SIB_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, rightSibKey, nodeKey);
+
+    // Field 2: leftSiblingKey (delta-varint)
+    heapOffsets[NodeFieldLayout.ARRAY_LEFT_SIB_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, leftSibKey, nodeKey);
+
+    // Field 3: firstChildKey (delta-varint)
+    heapOffsets[NodeFieldLayout.ARRAY_FIRST_CHILD_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, firstChildKey, nodeKey);
+
+    // Field 4: lastChildKey (delta-varint)
+    heapOffsets[NodeFieldLayout.ARRAY_LAST_CHILD_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, lastChildKey, nodeKey);
+
+    // Field 5: pathNodeKey (delta-varint)
+    heapOffsets[NodeFieldLayout.ARRAY_PATH_NODE_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, pathNodeKey, nodeKey);
+
+    // Field 6: previousRevision (signed varint)
+    heapOffsets[NodeFieldLayout.ARRAY_PREV_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, prevRev);
+
+    // Field 7: lastModifiedRevision (signed varint)
+    heapOffsets[NodeFieldLayout.ARRAY_LAST_MOD_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, lastModRev);
+
+    // Field 8: hash (fixed 8 bytes)
+    heapOffsets[NodeFieldLayout.ARRAY_HASH] = (int) (pos - dataStart);
+    DeltaVarIntCodec.writeLongToSegment(target, pos, hash);
+    pos += Long.BYTES;
+
+    // Field 9: childCount (signed long varint)
+    heapOffsets[NodeFieldLayout.ARRAY_CHILD_COUNT] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedLongToSegment(target, pos, childCount);
+
+    // Field 10: descendantCount (signed long varint)
+    heapOffsets[NodeFieldLayout.ARRAY_DESCENDANT_COUNT] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedLongToSegment(target, pos, descendantCount);
+
+    // Write offset table
+    for (int i = 0; i < FIELD_COUNT; i++) {
+      target.set(ValueLayout.JAVA_BYTE, offsetTableStart + i, (byte) heapOffsets[i]);
+    }
+
+    return (int) (pos - offset);
+  }
+
+  /**
+   * Serialize this node from Java fields. Delegates to static writeNewRecord.
+   */
+  public int serializeToHeap(final MemorySegment target, final long offset) {
+    if (!lazyFieldsParsed) {
+      parseLazyFields();
+    }
+    return writeNewRecord(target, offset, heapOffsets, nodeKey,
+        parentKey, rightSiblingKey, leftSiblingKey,
+        firstChildKey, lastChildKey, pathNodeKey,
+        previousRevision, lastModifiedRevision,
+        hash, childCount, descendantCount);
+  }
+
+  /**
+   * Get the pre-allocated heap offsets array for use with static writeNewRecord.
+   */
+  public int[] getHeapOffsets() {
+    return heapOffsets;
+  }
+
+  /**
+   * Set DeweyID fields directly after creation, bypassing write-through.
+   * The DeweyID is already in the page trailer -- this just sets the Java cache fields.
+   */
+  public void setDeweyIDAfterCreation(final SirixDeweyID id, final byte[] bytes) {
+    this.sirixDeweyID = id;
+    this.deweyIDBytes = bytes;
   }
 
   @Override
@@ -169,16 +433,38 @@ public long getNodeKey() {
 
   @Override
   public long getParentKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.ARRAY_PARENT_KEY, nodeKey);
+    }
     return parentKey;
   }
 
   public void setParentKey(final long parentKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.ARRAY_PARENT_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(parentKey, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, parentKey, nodeKey);
+        return;
+      }
+      resizeParentKey(parentKey);
+      return;
+    }
     this.parentKey = parentKey;
   }
 
+  private void resizeParentKey(final long value) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ARRAY_PARENT_KEY, NodeFieldLayout.ARRAY_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, value, nodeKey));
+  }
+
   @Override
   public boolean hasParent() {
-    return parentKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getParentKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
@@ -193,27 +479,79 @@ public void setTypeKey(final int typeKey) {
 
   @Override
   public void setDeweyID(final SirixDeweyID id) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.sirixDeweyID = id;
+      this.deweyIDBytes = null;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
     this.sirixDeweyID = id;
     this.deweyIDBytes = null;
   }
 
-  public void setDeweyIDBytes(final byte[] deweyIDBytes) {
-    this.deweyIDBytes = deweyIDBytes;
+  @Override
+  public void setDeweyIDBytes(final byte[] bytes) {
+    this.deweyIDBytes = bytes;
     this.sirixDeweyID = null;
   }
 
   @Override
   public void setPreviousRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.ARRAY_PREV_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizePreviousRevision(revision);
+      return;
+    }
     this.previousRevision = revision;
   }
 
+  private void resizePreviousRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ARRAY_PREV_REVISION, NodeFieldLayout.ARRAY_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+  }
+
   @Override
   public void setLastModifiedRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.ARRAY_LAST_MOD_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizeLastModifiedRevision(revision);
+      return;
+    }
     this.lastModifiedRevision = revision;
   }
 
+  private void resizeLastModifiedRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ARRAY_LAST_MOD_REVISION, NodeFieldLayout.ARRAY_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+  }
+
   @Override
   public long getHash() {
+    if (page != null) {
+      return readLongField(NodeFieldLayout.ARRAY_HASH);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
@@ -222,13 +560,22 @@ public long getHash() {
 
   @Override
   public void setHash(final long hash) {
+    if (page != null) {
+      // Hash is ALWAYS in-place (fixed 8 bytes)
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.ARRAY_HASH) & 0xFF;
+      DeltaVarIntCodec.writeLongToSegment(page, dataRegionStart + fieldOff, hash);
+      return;
+    }
     this.hash = hash;
   }
 
   @Override
   public long computeHash(final BytesOut bytes) {
     bytes.clear();
-    bytes.writeLong(getNodeKey()).writeLong(getParentKey()).writeByte(getKind().getId());
+    bytes.writeLong(getNodeKey())
+         .writeLong(getParentKey())
+         .writeByte(getKind().getId());
 
     bytes.writeLong(getChildCount())
          .writeLong(getDescendantCount())
@@ -247,45 +594,133 @@ public long computeHash(final BytesOut bytes) {
 
   @Override
   public long getRightSiblingKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.ARRAY_RIGHT_SIB_KEY, nodeKey);
+    }
     return rightSiblingKey;
   }
 
   public void setRightSiblingKey(final long rightSibling) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.ARRAY_RIGHT_SIB_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(rightSibling, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, rightSibling, nodeKey);
+        return;
+      }
+      resizeRightSiblingKey(rightSibling);
+      return;
+    }
     this.rightSiblingKey = rightSibling;
   }
 
+  private void resizeRightSiblingKey(final long value) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ARRAY_RIGHT_SIB_KEY, NodeFieldLayout.ARRAY_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, value, nodeKey));
+  }
+
   @Override
   public long getLeftSiblingKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.ARRAY_LEFT_SIB_KEY, nodeKey);
+    }
     return leftSiblingKey;
   }
 
   public void setLeftSiblingKey(final long leftSibling) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.ARRAY_LEFT_SIB_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(leftSibling, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, leftSibling, nodeKey);
+        return;
+      }
+      resizeLeftSiblingKey(leftSibling);
+      return;
+    }
     this.leftSiblingKey = leftSibling;
   }
 
+  private void resizeLeftSiblingKey(final long value) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ARRAY_LEFT_SIB_KEY, NodeFieldLayout.ARRAY_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, value, nodeKey));
+  }
+
   @Override
   public long getFirstChildKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.ARRAY_FIRST_CHILD_KEY, nodeKey);
+    }
     return firstChildKey;
   }
 
   public void setFirstChildKey(final long firstChild) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.ARRAY_FIRST_CHILD_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(firstChild, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, firstChild, nodeKey);
+        return;
+      }
+      resizeFirstChildKey(firstChild);
+      return;
+    }
     this.firstChildKey = firstChild;
   }
 
+  private void resizeFirstChildKey(final long value) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ARRAY_FIRST_CHILD_KEY, NodeFieldLayout.ARRAY_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, value, nodeKey));
+  }
+
   @Override
   public long getLastChildKey() {
-    if (!lazyFieldsParsed) {
-      parseLazyFields();
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.ARRAY_LAST_CHILD_KEY, nodeKey);
     }
     return lastChildKey;
   }
 
   public void setLastChildKey(final long lastChild) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.ARRAY_LAST_CHILD_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(lastChild, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, lastChild, nodeKey);
+        return;
+      }
+      resizeLastChildKey(lastChild);
+      return;
+    }
     this.lastChildKey = lastChild;
   }
 
+  private void resizeLastChildKey(final long value) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ARRAY_LAST_CHILD_KEY, NodeFieldLayout.ARRAY_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, value, nodeKey));
+  }
+
   @Override
   public long getChildCount() {
+    if (page != null) {
+      return readSignedLongField(NodeFieldLayout.ARRAY_CHILD_COUNT);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
@@ -293,11 +728,33 @@ public long getChildCount() {
   }
 
   public void setChildCount(final long childCount) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.ARRAY_CHILD_COUNT) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedLongEncodedWidth(childCount);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedLongToSegment(page, absOff, childCount);
+        return;
+      }
+      resizeChildCount(childCount);
+      return;
+    }
     this.childCount = childCount;
   }
 
+  private void resizeChildCount(final long value) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ARRAY_CHILD_COUNT, NodeFieldLayout.ARRAY_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedLongToSegment(target, off, value));
+  }
+
   @Override
   public long getDescendantCount() {
+    if (page != null) {
+      return readSignedLongField(NodeFieldLayout.ARRAY_DESCENDANT_COUNT);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
@@ -305,75 +762,104 @@ public long getDescendantCount() {
   }
 
   public void setDescendantCount(final long descendantCount) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.ARRAY_DESCENDANT_COUNT) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedLongEncodedWidth(descendantCount);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedLongToSegment(page, absOff, descendantCount);
+        return;
+      }
+      resizeDescendantCount(descendantCount);
+      return;
+    }
     this.descendantCount = descendantCount;
   }
 
+  private void resizeDescendantCount(final long value) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ARRAY_DESCENDANT_COUNT, NodeFieldLayout.ARRAY_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedLongToSegment(target, off, value));
+  }
+
   public long getPathNodeKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.ARRAY_PATH_NODE_KEY, nodeKey);
+    }
     return pathNodeKey;
   }
 
   public ArrayNode setPathNodeKey(final @NonNegative long pathNodeKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.ARRAY_PATH_NODE_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(pathNodeKey, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, pathNodeKey, nodeKey);
+        return this;
+      }
+      resizePathNodeKey(pathNodeKey);
+      return this;
+    }
     this.pathNodeKey = pathNodeKey;
     return this;
   }
 
+  private void resizePathNodeKey(final long value) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ARRAY_PATH_NODE_KEY, NodeFieldLayout.ARRAY_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, value, nodeKey));
+  }
+
   @Override
   public boolean hasFirstChild() {
-    return firstChildKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getFirstChildKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public boolean hasLastChild() {
-    if (!lazyFieldsParsed) {
-      parseLazyFields();
-    }
-    return lastChildKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getLastChildKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public void incrementChildCount() {
-    if (!lazyFieldsParsed) {
-      parseLazyFields();
-    }
-    childCount++;
+    setChildCount(getChildCount() + 1);
   }
 
   @Override
   public void decrementChildCount() {
-    if (!lazyFieldsParsed) {
-      parseLazyFields();
-    }
-    childCount--;
+    setChildCount(getChildCount() - 1);
   }
 
   @Override
   public void incrementDescendantCount() {
-    if (!lazyFieldsParsed) {
-      parseLazyFields();
-    }
-    descendantCount++;
+    setDescendantCount(getDescendantCount() + 1);
   }
 
   @Override
   public void decrementDescendantCount() {
-    if (!lazyFieldsParsed) {
-      parseLazyFields();
-    }
-    descendantCount--;
+    setDescendantCount(getDescendantCount() - 1);
   }
 
   @Override
   public boolean hasLeftSibling() {
-    return leftSiblingKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getLeftSiblingKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public boolean hasRightSibling() {
-    return rightSiblingKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getRightSiblingKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public int getPreviousRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.ARRAY_PREV_REVISION);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
@@ -382,6 +868,9 @@ public int getPreviousRevisionNumber() {
 
   @Override
   public int getLastModifiedRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.ARRAY_LAST_MOD_REVISION);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
@@ -398,11 +887,13 @@ public void setNodeKey(final long nodeKey) {
   }
 
   /**
-   * Populate this node from a BytesIn source for singleton reuse. LAZY OPTIMIZATION: Only parses
-   * structural fields immediately (NEW ORDER).
+   * Populate this node from a BytesIn source for singleton reuse.
+   * LAZY OPTIMIZATION: Only parses structural fields immediately (NEW ORDER).
    */
   public void readFrom(final BytesIn source, final long nodeKey, final byte[] deweyId,
-      final LongHashFunction hashFunction, final ResourceConfiguration config) {
+                       final LongHashFunction hashFunction, final ResourceConfiguration config) {
+    // Unbind flyweight — ensures getters use Java fields, not stale page reference
+    this.page = null;
     this.nodeKey = nodeKey;
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyId;
@@ -422,46 +913,24 @@ public void readFrom(final BytesIn source, final long nodeKey, final byte[] d
     this.lazyFieldsParsed = false;
     this.hasHash = config.hashType != HashType.NONE;
     this.storeChildCount = config.storeChildCount();
-
+    
     this.previousRevision = 0;
     this.lastModifiedRevision = 0;
     this.childCount = 0;
     this.hash = 0;
     this.descendantCount = 0;
   }
-
-  public void bindFixedSlotLazy(final MemorySegment slotData, final long baseOffset, final NodeKindLayout layout) {
-    this.lazyBaseOffset = baseOffset;
-    this.lazySource = slotData;
-    this.fixedSlotLayout = layout;
-    this.lazyFieldsParsed = false;
-  }
-
+  
   private void parseLazyFields() {
     if (lazyFieldsParsed) {
       return;
     }
-
-    if (fixedSlotLayout != null) {
-      final MemorySegment sd = (MemorySegment) lazySource;
-      final NodeKindLayout ly = fixedSlotLayout;
-      final long off = this.lazyBaseOffset;
-      this.previousRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.PREVIOUS_REVISION);
-      this.lastModifiedRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.LAST_MODIFIED_REVISION);
-      this.lastChildKey = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.LAST_CHILD_KEY);
-      this.childCount = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.CHILD_COUNT);
-      this.descendantCount = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.DESCENDANT_COUNT);
-      this.hash = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.HASH);
-      this.fixedSlotLayout = null;
-      this.lazyFieldsParsed = true;
-      return;
-    }
-
+    
     if (lazySource == null) {
       lazyFieldsParsed = true;
       return;
     }
-
+    
     BytesIn bytesIn;
     if (lazySource instanceof MemorySegment segment) {
       bytesIn = new MemorySegmentBytesIn(segment);
@@ -472,12 +941,10 @@ private void parseLazyFields() {
     } else {
       throw new IllegalStateException("Unknown lazy source type: " + lazySource.getClass());
     }
-
+    
     this.previousRevision = DeltaVarIntCodec.decodeSigned(bytesIn);
     this.lastModifiedRevision = DeltaVarIntCodec.decodeSigned(bytesIn);
-    this.childCount = storeChildCount
-        ? DeltaVarIntCodec.decodeSigned(bytesIn)
-        : 0;
+    this.childCount = storeChildCount ? DeltaVarIntCodec.decodeSigned(bytesIn) : 0;
     if (hasHash) {
       this.hash = bytesIn.readLong();
       this.descendantCount = DeltaVarIntCodec.decodeSigned(bytesIn);
@@ -486,18 +953,44 @@ private void parseLazyFields() {
   }
 
   /**
-   * Create a deep copy snapshot of this node. Forces parsing of all lazy fields since snapshot must
-   * be independent.
+   * Create a deep copy snapshot of this node.
+   * Forces parsing of all lazy fields since snapshot must be independent.
    */
   public ArrayNode toSnapshot() {
+    if (page != null) {
+      // Bound mode: read all fields from page
+      return new ArrayNode(nodeKey,
+          readDeltaField(NodeFieldLayout.ARRAY_PARENT_KEY, nodeKey),
+          readDeltaField(NodeFieldLayout.ARRAY_PATH_NODE_KEY, nodeKey),
+          readSignedField(NodeFieldLayout.ARRAY_PREV_REVISION),
+          readSignedField(NodeFieldLayout.ARRAY_LAST_MOD_REVISION),
+          readDeltaField(NodeFieldLayout.ARRAY_RIGHT_SIB_KEY, nodeKey),
+          readDeltaField(NodeFieldLayout.ARRAY_LEFT_SIB_KEY, nodeKey),
+          readDeltaField(NodeFieldLayout.ARRAY_FIRST_CHILD_KEY, nodeKey),
+          readDeltaField(NodeFieldLayout.ARRAY_LAST_CHILD_KEY, nodeKey),
+          readSignedLongField(NodeFieldLayout.ARRAY_CHILD_COUNT),
+          readSignedLongField(NodeFieldLayout.ARRAY_DESCENDANT_COUNT),
+          readLongField(NodeFieldLayout.ARRAY_HASH),
+          hashFunction,
+          getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
-    return new ArrayNode(nodeKey, parentKey, pathNodeKey, previousRevision, lastModifiedRevision, rightSiblingKey,
-        leftSiblingKey, firstChildKey, lastChildKey, childCount, descendantCount, hash, hashFunction,
-        deweyIDBytes != null
-            ? deweyIDBytes.clone()
-            : null);
+    return new ArrayNode(nodeKey, parentKey, pathNodeKey, previousRevision, lastModifiedRevision,
+        rightSiblingKey, leftSiblingKey, firstChildKey, lastChildKey, childCount,
+        descendantCount, hash, hashFunction,
+        getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null);
+  }
+
+  @Override
+  public boolean isWriteSingleton() {
+    return writeSingleton;
+  }
+
+  @Override
+  public void setWriteSingleton(final boolean writeSingleton) {
+    this.writeSingleton = writeSingleton;
   }
 
   @Override
@@ -549,6 +1042,7 @@ public boolean equals(final Object obj) {
     if (!(obj instanceof final ArrayNode other))
       return false;
 
-    return nodeKey == other.nodeKey && parentKey == other.parentKey;
+    return nodeKey == other.nodeKey
+        && parentKey == other.parentKey;
   }
 }
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/json/BooleanNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/json/BooleanNode.java
index 15d42dcc1..3dbbf005a 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/json/BooleanNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/json/BooleanNode.java
@@ -31,9 +31,9 @@
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Objects;
 import io.sirix.access.ResourceConfiguration;
-import io.sirix.access.trx.node.HashType;
 import io.sirix.api.visitor.JsonNodeVisitor;
 import io.sirix.api.visitor.VisitResult;
+import io.sirix.node.Bytes;
 import io.sirix.node.ByteArrayBytesIn;
 import io.sirix.node.BytesIn;
 import io.sirix.node.BytesOut;
@@ -43,15 +43,15 @@
 import io.sirix.node.SirixDeweyID;
 
 import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
 import io.sirix.node.immutable.json.ImmutableBooleanNode;
-import io.sirix.node.layout.NodeKindLayout;
-import io.sirix.node.layout.SlotLayoutAccessors;
-import io.sirix.node.layout.StructuralField;
 import io.sirix.node.interfaces.BooleanValueNode;
+import io.sirix.node.interfaces.FlyweightNode;
 import io.sirix.node.interfaces.Node;
-import io.sirix.node.interfaces.ReusableNodeProxy;
 import io.sirix.node.interfaces.StructNode;
 import io.sirix.node.interfaces.immutable.ImmutableJsonNode;
+import io.sirix.page.KeyValueLeafPage;
+import io.sirix.page.NodeFieldLayout;
 import io.sirix.settings.Fixed;
 import net.openhft.hashing.LongHashFunction;
 import org.checkerframework.checker.nullness.qual.NonNull;
@@ -60,13 +60,11 @@
 /**
  * JSON Boolean node.
  *
- * 

- * Uses primitive fields for efficient storage with delta+varint encoding.
- * 

- * 
+ * 
Uses primitive fields for efficient storage with delta+varint encoding.

+ *
  * @author Johannes Lichtenberger
  */
-public final class BooleanNode implements StructNode, ImmutableJsonNode, BooleanValueNode, ReusableNodeProxy {
+public final class BooleanNode implements StructNode, ImmutableJsonNode, BooleanValueNode, FlyweightNode {
 
   // Node identity (mutable for singleton reuse)
   private long nodeKey;
@@ -95,19 +93,52 @@ public final class BooleanNode implements StructNode, ImmutableJsonNode, Boolean
 
   // Lazy parsing state (single-stage since boolean value is cheap)
   private Object lazySource;
-  private long lazyBaseOffset;
   private long lazyOffset;
   private boolean lazyFieldsParsed;
-  private boolean hasHash;
+  // ==================== FLYWEIGHT BINDING (LeanStore page-direct access) ====================
+
+  /** Page MemorySegment when bound (null = primitive mode). */
+  private MemorySegment page;
+
+  /** Absolute byte offset of this record in the page (after HEAP_START + heapOffset). */
+  private long recordBase;
+
+  /** Absolute byte offset where the data region starts (recordBase + 1 + FIELD_COUNT). */
+  private long dataRegionStart;
+
+  /** Slot index in the page directory (for re-serialization). */
+  private int slotIndex;
+
+  /** True if this node is a factory-managed write singleton (must not be stored in records[]). */
+  private boolean writeSingleton;
+
+  /** Owning page for resize-in-place on varint width changes. */
+  private KeyValueLeafPage ownerPage;
+
+  /** Pre-allocated offset array reused across serializations (zero-alloc hot path). */
+  private final int[] heapOffsets;
 
-  // Fixed-slot lazy support
-  private NodeKindLayout fixedSlotLayout;
+  private static final int FIELD_COUNT = NodeFieldLayout.BOOLEAN_VALUE_FIELD_COUNT;
+
+  /**
+   * Constructor for flyweight binding.
+   * All fields except nodeKey and hashFunction will be read from page memory after bind().
+   *
+   * @param nodeKey the node key
+   * @param hashFunction the hash function from resource config
+   */
+  public BooleanNode(long nodeKey, LongHashFunction hashFunction) {
+    this.nodeKey = nodeKey;
+    this.hashFunction = hashFunction;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
 
   /**
    * Primary constructor with all primitive fields.
    */
-  public BooleanNode(long nodeKey, long parentKey, int previousRevision, int lastModifiedRevision, long rightSiblingKey,
-      long leftSiblingKey, long hash, boolean value, LongHashFunction hashFunction, byte[] deweyID) {
+  public BooleanNode(long nodeKey, long parentKey, int previousRevision,
+      int lastModifiedRevision, long rightSiblingKey, long leftSiblingKey, long hash,
+      boolean value, LongHashFunction hashFunction, byte[] deweyID) {
     this.nodeKey = nodeKey;
     this.parentKey = parentKey;
     this.previousRevision = previousRevision;
@@ -119,13 +150,15 @@ public BooleanNode(long nodeKey, long parentKey, int previousRevision, int lastM
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyID;
     this.lazyFieldsParsed = true;
+    this.heapOffsets = new int[FIELD_COUNT];
   }
 
   /**
    * Constructor with SirixDeweyID instead of byte array.
    */
-  public BooleanNode(long nodeKey, long parentKey, int previousRevision, int lastModifiedRevision, long rightSiblingKey,
-      long leftSiblingKey, long hash, boolean value, LongHashFunction hashFunction, SirixDeweyID deweyID) {
+  public BooleanNode(long nodeKey, long parentKey, int previousRevision,
+      int lastModifiedRevision, long rightSiblingKey, long leftSiblingKey, long hash,
+      boolean value, LongHashFunction hashFunction, SirixDeweyID deweyID) {
     this.nodeKey = nodeKey;
     this.parentKey = parentKey;
     this.previousRevision = previousRevision;
@@ -137,6 +170,208 @@ public BooleanNode(long nodeKey, long parentKey, int previousRevision, int lastM
     this.hashFunction = hashFunction;
     this.sirixDeweyID = deweyID;
     this.lazyFieldsParsed = true;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
+
+  // ==================== FLYWEIGHT BIND/UNBIND ====================
+
+  /**
+   * Bind this node as a flyweight to a page MemorySegment.
+   * When bound, getters/setters read/write directly to page memory via the offset table.
+   *
+   * @param page       the page MemorySegment
+   * @param recordBase absolute byte offset of this record in the page
+   * @param nodeKey    the node key (for delta decoding)
+   * @param slotIndex  the slot index in the page directory
+   */
+  public void bind(final MemorySegment page, final long recordBase, final long nodeKey,
+      final int slotIndex) {
+    this.page = page;
+    this.recordBase = recordBase;
+    this.nodeKey = nodeKey;
+    this.slotIndex = slotIndex;
+    this.dataRegionStart = recordBase + 1 + FIELD_COUNT;
+    this.hash = 0;
+    this.lazyFieldsParsed = true; // No lazy state when bound
+    this.lazySource = null;
+  }
+
+  /**
+   * Unbind from page memory and materialize all fields into Java primitives.
+   * After unbind, the node operates in primitive mode.
+   */
+  public void unbind() {
+    if (page == null) {
+      return;
+    }
+    // Materialize all fields from page to Java primitives
+    final long nk = this.nodeKey;
+    this.parentKey = readDeltaField(NodeFieldLayout.BOOLVAL_PARENT_KEY, nk);
+    this.rightSiblingKey = readDeltaField(NodeFieldLayout.BOOLVAL_RIGHT_SIB_KEY, nk);
+    this.leftSiblingKey = readDeltaField(NodeFieldLayout.BOOLVAL_LEFT_SIB_KEY, nk);
+    this.previousRevision = readSignedField(NodeFieldLayout.BOOLVAL_PREV_REVISION);
+    this.lastModifiedRevision = readSignedField(NodeFieldLayout.BOOLVAL_LAST_MOD_REVISION);
+    this.value = readByteField(NodeFieldLayout.BOOLVAL_VALUE) != 0;
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  @Override
+  public void clearBinding() {
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  /** Check if this node is bound to a page MemorySegment. */
+  public boolean isBound() {
+    return page != null;
+  }
+
+  @Override
+  public boolean isBoundTo(final MemorySegment page) {
+    return this.page == page;
+  }
+
+  @Override
+  public int getSlotIndex() {
+    return slotIndex;
+  }
+
+  // ==================== FLYWEIGHT FIELD READ HELPERS ====================
+
+  private long readDeltaField(final int fieldIndex, final long baseKey) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeDeltaFromSegment(page, dataRegionStart + fieldOff, baseKey);
+  }
+
+  private int readSignedField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeSignedFromSegment(page, dataRegionStart + fieldOff);
+  }
+
+  private byte readByteField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return page.get(ValueLayout.JAVA_BYTE, dataRegionStart + fieldOff);
+  }
+
+  /**
+   * Resize a single field via raw-copy on the owning slotted page.
+   * Avoids the full unbind-to-primitives + re-serialize round-trip.
+   *
+   * @param fieldIndex the field index in the offset table (e.g. {@code BOOLVAL_PARENT_KEY})
+   * @param encoder    writes the new field value at the target offset
+   */
+  private void resizeRecordField(final int fieldIndex,
+      final DeltaVarIntCodec.FieldEncoder encoder) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex, fieldIndex, FIELD_COUNT, encoder);
+  }
+
+  // ==================== OWNER PAGE (for resize-in-place) ====================
+
+  @Override
+  public KeyValueLeafPage getOwnerPage() {
+    return ownerPage;
+  }
+
+  @Override
+  public void setOwnerPage(final KeyValueLeafPage ownerPage) {
+    this.ownerPage = ownerPage;
+  }
+
+  // ==================== SERIALIZE TO HEAP ====================
+
+  /**
+   * Encode a BooleanNode record directly to a MemorySegment from parameter values.
+   * Static -- reads nothing from any instance. Zero field intermediation.
+   *
+   * @param target      the target MemorySegment (reinterpreted slotted page)
+   * @param offset      absolute byte offset to write at
+   * @param heapOffsets pre-allocated offset array (reused, FIELD_COUNT elements)
+   * @param nodeKey     the node key (delta base for structural keys)
+   * @param parentKey   the parent node key
+   * @param rightSibKey the right sibling key
+   * @param leftSibKey  the left sibling key
+   * @param prevRev     the previous revision number
+   * @param lastModRev  the last modified revision number
+   * @param boolValue   the boolean value
+   * @return the total number of bytes written
+   */
+  public static int writeNewRecord(final MemorySegment target, final long offset,
+      final int[] heapOffsets, final long nodeKey,
+      final long parentKey, final long rightSibKey, final long leftSibKey,
+      final int prevRev, final int lastModRev, final boolean boolValue) {
+    long pos = offset;
+
+    // Write nodeKind byte
+    target.set(ValueLayout.JAVA_BYTE, pos, NodeKind.BOOLEAN_VALUE.getId());
+    pos++;
+
+    // Reserve space for offset table
+    final long offsetTableStart = pos;
+    pos += FIELD_COUNT;
+
+    // Data region start
+    final long dataStart = pos;
+
+    // Field 0: parentKey (delta-varint)
+    heapOffsets[NodeFieldLayout.BOOLVAL_PARENT_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, parentKey, nodeKey);
+
+    // Field 1: rightSiblingKey (delta-varint)
+    heapOffsets[NodeFieldLayout.BOOLVAL_RIGHT_SIB_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, rightSibKey, nodeKey);
+
+    // Field 2: leftSiblingKey (delta-varint)
+    heapOffsets[NodeFieldLayout.BOOLVAL_LEFT_SIB_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, leftSibKey, nodeKey);
+
+    // Field 3: previousRevision (signed varint)
+    heapOffsets[NodeFieldLayout.BOOLVAL_PREV_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, prevRev);
+
+    // Field 4: lastModifiedRevision (signed varint)
+    heapOffsets[NodeFieldLayout.BOOLVAL_LAST_MOD_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, lastModRev);
+
+    // Field 5: value (1 byte boolean)
+    heapOffsets[NodeFieldLayout.BOOLVAL_VALUE] = (int) (pos - dataStart);
+    target.set(ValueLayout.JAVA_BYTE, pos, (byte) (boolValue ? 1 : 0));
+    pos += 1;
+
+    // Write offset table
+    for (int i = 0; i < FIELD_COUNT; i++) {
+      target.set(ValueLayout.JAVA_BYTE, offsetTableStart + i, (byte) heapOffsets[i]);
+    }
+
+    return (int) (pos - offset);
+  }
+
+  /**
+   * Serialize this node from Java fields. Delegates to static writeNewRecord.
+   */
+  public int serializeToHeap(final MemorySegment target, final long offset) {
+    if (!lazyFieldsParsed) {
+      parseLazyFields();
+    }
+    return writeNewRecord(target, offset, heapOffsets, nodeKey,
+        parentKey, rightSiblingKey, leftSiblingKey,
+        previousRevision, lastModifiedRevision, value);
+  }
+
+  /**
+   * Get the pre-allocated heap offsets array for use with static writeNewRecord.
+   */
+  public int[] getHeapOffsets() {
+    return heapOffsets;
+  }
+
+  /**
+   * Set DeweyID fields directly after creation, bypassing write-through.
+   * The DeweyID is already in the page trailer -- this just sets the Java cache fields.
+   */
+  public void setDeweyIDAfterCreation(final SirixDeweyID id, final byte[] bytes) {
+    this.sirixDeweyID = id;
+    this.deweyIDBytes = bytes;
   }
 
   @Override
@@ -151,16 +386,33 @@ public long getNodeKey() {
 
   @Override
   public long getParentKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.BOOLVAL_PARENT_KEY, nodeKey);
+    }
     return parentKey;
   }
 
   public void setParentKey(final long parentKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.BOOLVAL_PARENT_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(parentKey, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, parentKey, nodeKey);
+        return;
+      }
+      resizeRecordField(NodeFieldLayout.BOOLVAL_PARENT_KEY,
+          (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, parentKey, nodeKey));
+      return;
+    }
     this.parentKey = parentKey;
   }
 
   @Override
   public boolean hasParent() {
-    return parentKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getParentKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
@@ -175,31 +427,73 @@ public void setTypeKey(final int typeKey) {
 
   @Override
   public void setDeweyID(final SirixDeweyID id) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.sirixDeweyID = id;
+      this.deweyIDBytes = null;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
     this.sirixDeweyID = id;
     this.deweyIDBytes = null;
   }
 
-  public void setDeweyIDBytes(final byte[] deweyIDBytes) {
-    this.deweyIDBytes = deweyIDBytes;
+  @Override
+  public void setDeweyIDBytes(final byte[] bytes) {
+    this.deweyIDBytes = bytes;
     this.sirixDeweyID = null;
   }
 
   @Override
   public void setPreviousRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.BOOLVAL_PREV_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizeRecordField(NodeFieldLayout.BOOLVAL_PREV_REVISION,
+          (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+      return;
+    }
     this.previousRevision = revision;
   }
 
   @Override
   public void setLastModifiedRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.BOOLVAL_LAST_MOD_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizeRecordField(NodeFieldLayout.BOOLVAL_LAST_MOD_REVISION,
+          (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+      return;
+    }
     this.lastModifiedRevision = revision;
   }
 
   @Override
   public long getHash() {
-    if (!lazyFieldsParsed) {
-      parseLazyFields();
+    if (hash != 0L) {
+      return hash;
     }
-    return hash;
+    if (hashFunction != null) {
+      return computeHash(Bytes.threadLocalHashBuffer());
+    }
+    return 0L;
   }
 
   @Override
@@ -210,17 +504,9 @@ public void setHash(final long hash) {
   @Override
   public long computeHash(final BytesOut bytes) {
     bytes.clear();
-    bytes.writeLong(getNodeKey()).writeLong(getParentKey()).writeByte(getKind().getId());
-
-    bytes.writeLong(getChildCount())
-         .writeLong(getDescendantCount())
-         .writeLong(getLeftSiblingKey())
-         .writeLong(getRightSiblingKey())
-         .writeLong(getFirstChildKey());
-
-    if (getLastChildKey() != Fixed.INVALID_KEY_FOR_TYPE_CHECK.getStandardProperty()) {
-      bytes.writeLong(getLastChildKey());
-    }
+    bytes.writeLong(getNodeKey())
+         .writeLong(getParentKey())
+         .writeByte(getKind().getId());
 
     bytes.writeBoolean(getValue());
 
@@ -229,19 +515,53 @@ public long computeHash(final BytesOut bytes) {
 
   @Override
   public long getRightSiblingKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.BOOLVAL_RIGHT_SIB_KEY, nodeKey);
+    }
     return rightSiblingKey;
   }
 
   public void setRightSiblingKey(final long rightSibling) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.BOOLVAL_RIGHT_SIB_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(rightSibling, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, rightSibling, nodeKey);
+        return;
+      }
+      resizeRecordField(NodeFieldLayout.BOOLVAL_RIGHT_SIB_KEY,
+          (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, rightSibling, nodeKey));
+      return;
+    }
     this.rightSiblingKey = rightSibling;
   }
 
   @Override
   public long getLeftSiblingKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.BOOLVAL_LEFT_SIB_KEY, nodeKey);
+    }
     return leftSiblingKey;
   }
 
   public void setLeftSiblingKey(final long leftSibling) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.BOOLVAL_LEFT_SIB_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(leftSibling, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, leftSibling, nodeKey);
+        return;
+      }
+      resizeRecordField(NodeFieldLayout.BOOLVAL_LEFT_SIB_KEY,
+          (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, leftSibling, nodeKey));
+      return;
+    }
     this.leftSiblingKey = leftSibling;
   }
 
@@ -282,6 +602,9 @@ public void setDescendantCount(final long descendantCount) {
   }
 
   public boolean getValue() {
+    if (page != null) {
+      return readByteField(NodeFieldLayout.BOOLVAL_VALUE) != 0;
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
@@ -289,6 +612,13 @@ public boolean getValue() {
   }
 
   public void setValue(final boolean value) {
+    if (page != null) {
+      // Boolean is always 1 byte, always fits in-place
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.BOOLVAL_VALUE) & 0xFF;
+      page.set(ValueLayout.JAVA_BYTE, dataRegionStart + fieldOff, (byte) (value ? 1 : 0));
+      return;
+    }
     this.value = value;
   }
 
@@ -324,16 +654,19 @@ public void decrementDescendantCount() {
 
   @Override
   public boolean hasLeftSibling() {
-    return leftSiblingKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getLeftSiblingKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public boolean hasRightSibling() {
-    return rightSiblingKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getRightSiblingKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public int getPreviousRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.BOOLVAL_PREV_REVISION);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
@@ -342,6 +675,9 @@ public int getPreviousRevisionNumber() {
 
   @Override
   public int getLastModifiedRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.BOOLVAL_LAST_MOD_REVISION);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
@@ -358,7 +694,9 @@ public void setNodeKey(final long nodeKey) {
   }
 
   public void readFrom(final BytesIn source, final long nodeKey, final byte[] deweyId,
-      final LongHashFunction hashFunction, final ResourceConfiguration config) {
+                       final LongHashFunction hashFunction, final ResourceConfiguration config) {
+    // Unbind flyweight — ensures getters use Java fields, not stale page reference
+    this.page = null;
     this.nodeKey = nodeKey;
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyId;
@@ -373,38 +711,17 @@ public void readFrom(final BytesIn source, final long nodeKey, final byte[] d
     this.lazySource = source.getSource();
     this.lazyOffset = source.position();
     this.lazyFieldsParsed = false;
-    this.hasHash = config.hashType != HashType.NONE;
-
     this.previousRevision = 0;
     this.lastModifiedRevision = 0;
     this.value = false;
     this.hash = 0;
   }
 
-  public void bindFixedSlotLazy(final MemorySegment slotData, final long baseOffset, final NodeKindLayout layout) {
-    this.lazyBaseOffset = baseOffset;
-    this.lazySource = slotData;
-    this.fixedSlotLayout = layout;
-    this.lazyFieldsParsed = false;
-  }
-
   private void parseLazyFields() {
     if (lazyFieldsParsed) {
       return;
     }
 
-    if (fixedSlotLayout != null) {
-      final MemorySegment sd = (MemorySegment) lazySource;
-      final NodeKindLayout ly = fixedSlotLayout;
-      final long off = this.lazyBaseOffset;
-      this.previousRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.PREVIOUS_REVISION);
-      this.lastModifiedRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.LAST_MODIFIED_REVISION);
-      this.hash = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.HASH);
-      this.fixedSlotLayout = null;
-      this.lazyFieldsParsed = true;
-      return;
-    }
-
     if (lazySource == null) {
       lazyFieldsParsed = true;
       return;
@@ -424,20 +741,39 @@ private void parseLazyFields() {
     this.previousRevision = DeltaVarIntCodec.decodeSigned(bytesIn);
     this.lastModifiedRevision = DeltaVarIntCodec.decodeSigned(bytesIn);
     this.value = bytesIn.readBoolean();
-    if (hasHash) {
-      this.hash = bytesIn.readLong();
-    }
     this.lazyFieldsParsed = true;
   }
 
   public BooleanNode toSnapshot() {
+    if (page != null) {
+      // Bound mode: read all fields from page
+      return new BooleanNode(nodeKey,
+          readDeltaField(NodeFieldLayout.BOOLVAL_PARENT_KEY, nodeKey),
+          readSignedField(NodeFieldLayout.BOOLVAL_PREV_REVISION),
+          readSignedField(NodeFieldLayout.BOOLVAL_LAST_MOD_REVISION),
+          readDeltaField(NodeFieldLayout.BOOLVAL_RIGHT_SIB_KEY, nodeKey),
+          readDeltaField(NodeFieldLayout.BOOLVAL_LEFT_SIB_KEY, nodeKey),
+          hash,
+          readByteField(NodeFieldLayout.BOOLVAL_VALUE) != 0,
+          hashFunction,
+          getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
-    return new BooleanNode(nodeKey, parentKey, previousRevision, lastModifiedRevision, rightSiblingKey, leftSiblingKey,
-        hash, value, hashFunction, deweyIDBytes != null
-            ? deweyIDBytes.clone()
-            : null);
+    return new BooleanNode(nodeKey, parentKey, previousRevision, lastModifiedRevision,
+        rightSiblingKey, leftSiblingKey, hash, value, hashFunction,
+        getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null);
+  }
+
+  @Override
+  public boolean isWriteSingleton() {
+    return writeSingleton;
+  }
+
+  @Override
+  public void setWriteSingleton(final boolean writeSingleton) {
+    this.writeSingleton = writeSingleton;
   }
 
   @Override
@@ -484,6 +820,8 @@ public boolean equals(final Object obj) {
     if (!(obj instanceof final BooleanNode other))
       return false;
 
-    return nodeKey == other.nodeKey && parentKey == other.parentKey && value == other.value;
+    return nodeKey == other.nodeKey
+        && parentKey == other.parentKey
+        && value == other.value;
   }
 }
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/json/JsonDocumentRootNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/json/JsonDocumentRootNode.java
index 9a825d6a0..1ceac4bc8 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/json/JsonDocumentRootNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/json/JsonDocumentRootNode.java
@@ -32,15 +32,15 @@
 import io.sirix.node.NodeKind;
 import io.sirix.node.SirixDeweyID;
 import io.sirix.node.immutable.json.ImmutableJsonDocumentRootNode;
+import io.sirix.node.interfaces.FlyweightNode;
 import io.sirix.node.interfaces.Node;
 import io.sirix.node.interfaces.StructNode;
 import io.sirix.node.interfaces.immutable.ImmutableJsonNode;
-import io.sirix.node.layout.NodeKindLayout;
-import io.sirix.node.layout.SlotLayoutAccessors;
-import io.sirix.node.layout.StructuralField;
+import io.sirix.page.KeyValueLeafPage;
+import io.sirix.page.NodeFieldLayout;
 import io.sirix.settings.Fixed;
-
 import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
 import net.openhft.hashing.LongHashFunction;
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
@@ -49,12 +49,12 @@
  * Node representing the root of a JSON document. This node is guaranteed to exist in revision 0 and
  * cannot be removed.
  *
- * 

- * Uses primitive fields for efficient storage following the ObjectNode pattern. Document root has
- * fixed values for nodeKey (0), parentKey (-1), and no siblings.
- * 

+ * 
Uses primitive fields for efficient storage following the ObjectNode pattern.
+ * Document root has fixed values for nodeKey (0), parentKey (-1), and no siblings.

+ *
+ * 
Supports flyweight binding to a page MemorySegment for zero-copy field access.

  */
-public final class JsonDocumentRootNode implements StructNode, ImmutableJsonNode {
+public final class JsonDocumentRootNode implements StructNode, ImmutableJsonNode, FlyweightNode {
 
   // === STRUCTURAL FIELDS (immediate) ===
 
@@ -89,15 +89,47 @@ public final class JsonDocumentRootNode implements StructNode, ImmutableJsonNode
   /** DeweyID as bytes. */
   private byte[] deweyIDBytes;
 
-  // Fixed-slot lazy support
-  private Object lazySource;
-  private long lazyBaseOffset;
-  private NodeKindLayout fixedSlotLayout;
-  private boolean lazyFieldsParsed = true;
+  // ==================== FLYWEIGHT BINDING (LeanStore page-direct access) ====================
+
+  /** Page MemorySegment when bound (null = primitive mode). */
+  private MemorySegment page;
+
+  /** Absolute byte offset of this record in the page (after HEAP_START + heapOffset). */
+  private long recordBase;
+
+  /** Absolute byte offset where the data region starts (recordBase + 1 + FIELD_COUNT). */
+  private long dataRegionStart;
+
+  /** Slot index in the page directory (for re-serialization). */
+  private int slotIndex;
+
+  /** True if this node is a factory-managed write singleton (must not be stored in records[]). */
+  private boolean writeSingleton;
+
+  /** Owning page for resize-in-place operations. */
+  private KeyValueLeafPage ownerPage;
+
+  /** Reusable offset array for serializeToHeap (avoids allocation). */
+  private final int[] heapOffsets;
+
+  private static final int FIELD_COUNT = NodeFieldLayout.JSON_DOCUMENT_ROOT_FIELD_COUNT;
 
   /**
-   * Primary constructor with all primitive fields. Used by deserialization
-   * (NodeKind.JSON_DOCUMENT.deserialize).
+   * Constructor for flyweight binding.
+   * All fields except nodeKey and hashFunction will be read from page memory after bind().
+   *
+   * @param nodeKey the node key
+   * @param hashFunction the hash function from resource config
+   */
+  public JsonDocumentRootNode(long nodeKey, LongHashFunction hashFunction) {
+    this.nodeKey = nodeKey;
+    this.hashFunction = hashFunction;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
+
+  /**
+   * Primary constructor with all primitive fields.
+   * Used by deserialization (NodeKind.JSON_DOCUMENT.deserialize).
    *
    * @param nodeKey the node key (always 0 for document root)
    * @param firstChildKey the first child key
@@ -106,8 +138,8 @@ public final class JsonDocumentRootNode implements StructNode, ImmutableJsonNode
    * @param descendantCount the descendant count
    * @param hashFunction the hash function
    */
-  public JsonDocumentRootNode(long nodeKey, long firstChildKey, long lastChildKey, long childCount,
-      long descendantCount, LongHashFunction hashFunction) {
+  public JsonDocumentRootNode(long nodeKey, long firstChildKey, long lastChildKey,
+      long childCount, long descendantCount, LongHashFunction hashFunction) {
     this.nodeKey = nodeKey;
     this.firstChildKey = firstChildKey;
     this.lastChildKey = lastChildKey;
@@ -115,6 +147,7 @@ public JsonDocumentRootNode(long nodeKey, long firstChildKey, long lastChildKey,
     this.descendantCount = descendantCount;
     this.hashFunction = hashFunction;
     this.deweyIDBytes = SirixDeweyID.newRootID().toBytes();
+    this.heapOffsets = new int[FIELD_COUNT];
   }
 
   /**
@@ -128,8 +161,9 @@ public JsonDocumentRootNode(long nodeKey, long firstChildKey, long lastChildKey,
    * @param hashFunction the hash function
    * @param deweyID the DeweyID
    */
-  public JsonDocumentRootNode(long nodeKey, long firstChildKey, long lastChildKey, long childCount,
-      long descendantCount, LongHashFunction hashFunction, SirixDeweyID deweyID) {
+  public JsonDocumentRootNode(long nodeKey, long firstChildKey, long lastChildKey,
+      long childCount, long descendantCount, LongHashFunction hashFunction,
+      SirixDeweyID deweyID) {
     this.nodeKey = nodeKey;
     this.firstChildKey = firstChildKey;
     this.lastChildKey = lastChildKey;
@@ -137,6 +171,184 @@ public JsonDocumentRootNode(long nodeKey, long firstChildKey, long lastChildKey,
     this.descendantCount = descendantCount;
     this.hashFunction = hashFunction;
     this.sirixDeweyID = deweyID;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
+
+  // ==================== FLYWEIGHT BIND/UNBIND ====================
+
+  /**
+   * Bind this node as a flyweight to a page MemorySegment.
+   * When bound, getters/setters read/write directly to page memory via the offset table.
+   *
+   * @param page       the page MemorySegment
+   * @param recordBase absolute byte offset of this record in the page
+   * @param nodeKey    the node key (for delta decoding)
+   * @param slotIndex  the slot index in the page directory
+   */
+  public void bind(final MemorySegment page, final long recordBase, final long nodeKey,
+      final int slotIndex) {
+    this.page = page;
+    this.recordBase = recordBase;
+    this.nodeKey = nodeKey;
+    this.slotIndex = slotIndex;
+    this.dataRegionStart = recordBase + 1 + FIELD_COUNT;
+  }
+
+  /**
+   * Unbind from page memory and materialize all fields into Java primitives.
+   * After unbind, the node operates in primitive mode.
+   */
+  public void unbind() {
+    if (page == null) {
+      return;
+    }
+    // Materialize all fields from page to Java primitives
+    final long nk = this.nodeKey;
+    this.firstChildKey = readDeltaField(NodeFieldLayout.JDOCROOT_FIRST_CHILD_KEY, nk);
+    this.lastChildKey = readDeltaField(NodeFieldLayout.JDOCROOT_LAST_CHILD_KEY, nk);
+    this.childCount = readSignedLongField(NodeFieldLayout.JDOCROOT_CHILD_COUNT);
+    this.descendantCount = readSignedLongField(NodeFieldLayout.JDOCROOT_DESCENDANT_COUNT);
+    this.hash = readLongField(NodeFieldLayout.JDOCROOT_HASH);
+    this.ownerPage = null;
+    this.page = null;
+  }
+
+  @Override
+  public void clearBinding() {
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  /** Check if this node is bound to a page MemorySegment. */
+  public boolean isBound() {
+    return page != null;
+  }
+
+  @Override
+  public boolean isBoundTo(final MemorySegment page) {
+    return this.page == page;
+  }
+
+  @Override
+  public int getSlotIndex() {
+    return slotIndex;
+  }
+
+  // ==================== FLYWEIGHT FIELD READ HELPERS ====================
+
+  private long readDeltaField(final int fieldIndex, final long baseKey) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeDeltaFromSegment(page, dataRegionStart + fieldOff, baseKey);
+  }
+
+  private int readSignedField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeSignedFromSegment(page, dataRegionStart + fieldOff);
+  }
+
+  private long readSignedLongField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeSignedLongFromSegment(page, dataRegionStart + fieldOff);
+  }
+
+  private long readLongField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.readLongFromSegment(page, (int) (dataRegionStart + fieldOff));
+  }
+
+  // ==================== SERIALIZE TO HEAP ====================
+
+  /**
+   * Encode a JsonDocumentRootNode record directly to a MemorySegment from parameter values.
+   * Static -- reads nothing from any instance. Zero field intermediation.
+   *
+   * @param target          the target MemorySegment (reinterpreted slotted page)
+   * @param offset          absolute byte offset to write at
+   * @param heapOffsets     pre-allocated offset array (reused, FIELD_COUNT elements)
+   * @param nodeKey         the node key (delta base for structural keys)
+   * @param firstChildKey   the first child key
+   * @param lastChildKey    the last child key
+   * @param childCount      the child count
+   * @param descendantCount the descendant count
+   * @param hash            the hash value
+   * @return the total number of bytes written
+   */
+  public static int writeNewRecord(final MemorySegment target, final long offset,
+      final int[] heapOffsets, final long nodeKey,
+      final long firstChildKey, final long lastChildKey,
+      final long childCount, final long descendantCount, final long hash) {
+    long pos = offset;
+
+    // Write nodeKind byte
+    target.set(ValueLayout.JAVA_BYTE, pos, NodeKind.JSON_DOCUMENT.getId());
+    pos++;
+
+    // Reserve space for offset table
+    final long offsetTableStart = pos;
+    pos += FIELD_COUNT;
+
+    // Data region start
+    final long dataStart = pos;
+
+    // Field 0: firstChildKey (delta-varint from nodeKey)
+    heapOffsets[NodeFieldLayout.JDOCROOT_FIRST_CHILD_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, firstChildKey, nodeKey);
+
+    // Field 1: lastChildKey (delta-varint from nodeKey)
+    heapOffsets[NodeFieldLayout.JDOCROOT_LAST_CHILD_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, lastChildKey, nodeKey);
+
+    // Field 2: childCount (signed long varint)
+    heapOffsets[NodeFieldLayout.JDOCROOT_CHILD_COUNT] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedLongToSegment(target, pos, childCount);
+
+    // Field 3: descendantCount (signed long varint)
+    heapOffsets[NodeFieldLayout.JDOCROOT_DESCENDANT_COUNT] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedLongToSegment(target, pos, descendantCount);
+
+    // Field 4: previousRevision (signed varint) -- always 0 for document root
+    heapOffsets[NodeFieldLayout.JDOCROOT_PREV_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, 0);
+
+    // Field 5: lastModifiedRevision (signed varint) -- always 0 for document root
+    heapOffsets[NodeFieldLayout.JDOCROOT_LAST_MOD_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, 0);
+
+    // Field 6: hash (fixed 8 bytes)
+    heapOffsets[NodeFieldLayout.JDOCROOT_HASH] = (int) (pos - dataStart);
+    DeltaVarIntCodec.writeLongToSegment(target, pos, hash);
+    pos += Long.BYTES;
+
+    // Write offset table
+    for (int i = 0; i < FIELD_COUNT; i++) {
+      target.set(ValueLayout.JAVA_BYTE, offsetTableStart + i, (byte) heapOffsets[i]);
+    }
+
+    return (int) (pos - offset);
+  }
+
+  /**
+   * Serialize this node from Java fields. Delegates to static writeNewRecord.
+   */
+  public int serializeToHeap(final MemorySegment target, final long offset) {
+    return writeNewRecord(target, offset, heapOffsets, nodeKey,
+        firstChildKey, lastChildKey, childCount, descendantCount, hash);
+  }
+
+  /**
+   * Get the pre-allocated heap offsets array for use with static writeNewRecord.
+   */
+  public int[] getHeapOffsets() {
+    return heapOffsets;
+  }
+
+  /**
+   * Set DeweyID fields directly after creation, bypassing write-through.
+   * The DeweyID is already in the page trailer -- this just sets the Java cache fields.
+   */
+  public void setDeweyIDAfterCreation(final SirixDeweyID id, final byte[] bytes) {
+    this.sirixDeweyID = id;
+    this.deweyIDBytes = bytes;
   }
 
   @Override
@@ -201,83 +413,155 @@ public boolean hasLeftSibling() {
 
   @Override
   public long getFirstChildKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.JDOCROOT_FIRST_CHILD_KEY, nodeKey);
+    }
     return firstChildKey;
   }
 
   @Override
   public void setFirstChildKey(long key) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.JDOCROOT_FIRST_CHILD_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(key, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, key, nodeKey);
+        return;
+      }
+      resizeFirstChildKey(key);
+      return;
+    }
     this.firstChildKey = key;
   }
 
+  private void resizeFirstChildKey(final long key) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.JDOCROOT_FIRST_CHILD_KEY, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, key, nodeKey));
+  }
+
   @Override
   public boolean hasFirstChild() {
-    return firstChildKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getFirstChildKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public long getLastChildKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.JDOCROOT_LAST_CHILD_KEY, nodeKey);
+    }
     return lastChildKey;
   }
 
   @Override
   public void setLastChildKey(long key) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.JDOCROOT_LAST_CHILD_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(key, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, key, nodeKey);
+        return;
+      }
+      resizeLastChildKey(key);
+      return;
+    }
     this.lastChildKey = key;
   }
 
+  private void resizeLastChildKey(final long key) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.JDOCROOT_LAST_CHILD_KEY, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, key, nodeKey));
+  }
+
   @Override
   public boolean hasLastChild() {
-    return lastChildKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getLastChildKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public long getChildCount() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
+    if (page != null) {
+      return readSignedLongField(NodeFieldLayout.JDOCROOT_CHILD_COUNT);
+    }
     return childCount;
   }
 
   public void setChildCount(long childCount) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.JDOCROOT_CHILD_COUNT) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedLongEncodedWidth(childCount);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedLongToSegment(page, absOff, childCount);
+        return;
+      }
+      resizeChildCount(childCount);
+      return;
+    }
     this.childCount = childCount;
   }
 
+  private void resizeChildCount(final long childCount) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.JDOCROOT_CHILD_COUNT, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedLongToSegment(target, off, childCount));
+  }
+
   @Override
   public void incrementChildCount() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
-    childCount++;
+    setChildCount(getChildCount() + 1);
   }
 
   @Override
   public void decrementChildCount() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
-    childCount--;
+    setChildCount(getChildCount() - 1);
   }
 
   @Override
   public long getDescendantCount() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
+    if (page != null) {
+      return readSignedLongField(NodeFieldLayout.JDOCROOT_DESCENDANT_COUNT);
+    }
     return descendantCount;
   }
 
   @Override
   public void setDescendantCount(long descendantCount) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.JDOCROOT_DESCENDANT_COUNT) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedLongEncodedWidth(descendantCount);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedLongToSegment(page, absOff, descendantCount);
+        return;
+      }
+      resizeDescendantCount(descendantCount);
+      return;
+    }
     this.descendantCount = descendantCount;
   }
 
+  private void resizeDescendantCount(final long descendantCount) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.JDOCROOT_DESCENDANT_COUNT, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedLongToSegment(target, off, descendantCount));
+  }
+
   @Override
   public void incrementDescendantCount() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
-    descendantCount++;
+    setDescendantCount(getDescendantCount() + 1);
   }
 
   @Override
   public void decrementDescendantCount() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
-    descendantCount--;
+    setDescendantCount(getDescendantCount() - 1);
   }
 
   @Override
@@ -287,54 +571,103 @@ public long computeHash(BytesOut bytes) {
     }
 
     bytes.clear();
-    bytes.writeLong(nodeKey).writeLong(getParentKey()).writeByte(getKind().getId());
+    bytes.writeLong(nodeKey)
+         .writeLong(getParentKey())
+         .writeByte(getKind().getId());
 
-    bytes.writeLong(childCount)
-         .writeLong(descendantCount)
+    bytes.writeLong(getChildCount())
+         .writeLong(getDescendantCount())
          .writeLong(getLeftSiblingKey())
          .writeLong(getRightSiblingKey())
-         .writeLong(firstChildKey);
+         .writeLong(getFirstChildKey());
 
-    if (lastChildKey != Fixed.INVALID_KEY_FOR_TYPE_CHECK.getStandardProperty()) {
-      bytes.writeLong(lastChildKey);
+    if (getLastChildKey() != Fixed.INVALID_KEY_FOR_TYPE_CHECK.getStandardProperty()) {
+      bytes.writeLong(getLastChildKey());
     }
 
-    final var buffer = ((java.nio.ByteBuffer) bytes.underlyingObject()).rewind();
-    buffer.limit((int) bytes.readLimit());
-
-    return hashFunction.hashBytes(buffer);
+    return bytes.hashDirect(hashFunction);
   }
 
   @Override
   public void setHash(long hash) {
+    if (page != null) {
+      // Hash is ALWAYS in-place (fixed 8 bytes)
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.JDOCROOT_HASH) & 0xFF;
+      DeltaVarIntCodec.writeLongToSegment(page, dataRegionStart + fieldOff, hash);
+      return;
+    }
     this.hash = hash;
   }
 
   @Override
   public long getHash() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
+    if (page != null) {
+      return readLongField(NodeFieldLayout.JDOCROOT_HASH);
+    }
     return hash;
   }
 
   @Override
   public int getPreviousRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.JDOCROOT_PREV_REVISION);
+    }
     return 0; // Document root is always in revision 0
   }
 
   @Override
   public void setPreviousRevision(int revision) {
-    // Document root doesn't track previous revision
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.JDOCROOT_PREV_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizePreviousRevision(revision);
+      return;
+    }
+    // Document root doesn't track previous revision in primitive mode
+  }
+
+  private void resizePreviousRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.JDOCROOT_PREV_REVISION, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
   }
 
   @Override
   public int getLastModifiedRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.JDOCROOT_LAST_MOD_REVISION);
+    }
     return 0;
   }
 
   @Override
   public void setLastModifiedRevision(int revision) {
-    // Document root doesn't track last modified revision
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.JDOCROOT_LAST_MOD_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizeLastModifiedRevision(revision);
+      return;
+    }
+    // Document root doesn't track last modified revision in primitive mode
+  }
+
+  private void resizeLastModifiedRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.JDOCROOT_LAST_MOD_REVISION, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
   }
 
   @Override
@@ -347,6 +680,19 @@ public void setTypeKey(int typeKey) {
     // Not supported for JSON nodes
   }
 
+  @Override
+  public boolean isWriteSingleton() {
+    return writeSingleton;
+  }
+
+  @Override
+  public void setWriteSingleton(final boolean writeSingleton) {
+    this.writeSingleton = writeSingleton;
+  }
+
+  @Override public KeyValueLeafPage getOwnerPage() { return ownerPage; }
+  @Override public void setOwnerPage(final KeyValueLeafPage p) { this.ownerPage = p; }
+
   @Override
   public SirixDeweyID getDeweyID() {
     if (sirixDeweyID == null && deweyIDBytes != null) {
@@ -371,12 +717,23 @@ public byte[] getDeweyIDAsBytes() {
 
   @Override
   public void setDeweyID(SirixDeweyID id) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.sirixDeweyID = id;
+      this.deweyIDBytes = null;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
     this.sirixDeweyID = id;
     this.deweyIDBytes = null;
   }
 
-  public void setDeweyIDBytes(final byte[] deweyIDBytes) {
-    this.deweyIDBytes = deweyIDBytes;
+  @Override
+  public void setDeweyIDBytes(final byte[] bytes) {
+    this.deweyIDBytes = bytes;
     this.sirixDeweyID = null;
   }
 
@@ -394,46 +751,19 @@ public LongHashFunction getHashFunction() {
    */
   public void readFrom(BytesIn source, long nodeKey, byte[] deweyId, LongHashFunction hashFunction,
       ResourceConfiguration config) {
-    final long firstChildKey = DeltaVarIntCodec.decodeDelta(source, nodeKey);
+    // Unbind flyweight -- ensures getters use Java fields, not stale page reference
+    this.page = null;
 
+    final long firstChildKey = DeltaVarIntCodec.decodeDelta(source, nodeKey);
     this.nodeKey = Fixed.DOCUMENT_NODE_KEY.getStandardProperty();
     this.firstChildKey = firstChildKey;
-    this.lastChildKey = firstChildKey;
-    this.childCount = firstChildKey == Fixed.NULL_NODE_KEY.getStandardProperty()
-        ? 0L
-        : 1L;
+    this.lastChildKey = firstChildKey; // lastChildKey same as firstChildKey for document root
+    this.childCount = firstChildKey == Fixed.NULL_NODE_KEY.getStandardProperty() ? 0L : 1L;
     this.descendantCount = DeltaVarIntCodec.decodeSignedLong(source);
+    this.hash = 0L;
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyId;
     this.sirixDeweyID = null;
-    this.hash = 0L;
-  }
-
-  public void bindFixedSlotLazy(final MemorySegment slotData, final long baseOffset, final NodeKindLayout layout) {
-    this.lazyBaseOffset = baseOffset;
-    this.lazySource = slotData;
-    this.fixedSlotLayout = layout;
-    this.lazyFieldsParsed = false;
-  }
-
-  private void parseLazyFields() {
-    if (lazyFieldsParsed) {
-      return;
-    }
-
-    if (fixedSlotLayout != null) {
-      final MemorySegment sd = (MemorySegment) lazySource;
-      final NodeKindLayout ly = fixedSlotLayout;
-      final long off = this.lazyBaseOffset;
-      this.childCount = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.CHILD_COUNT);
-      this.descendantCount = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.DESCENDANT_COUNT);
-      this.hash = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.HASH);
-      this.fixedSlotLayout = null;
-      this.lazyFieldsParsed = true;
-      return;
-    }
-
-    this.lazyFieldsParsed = true;
   }
 
   /**
@@ -442,10 +772,27 @@ private void parseLazyFields() {
    * @return a new instance with copied values
    */
   public JsonDocumentRootNode toSnapshot() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
-    final JsonDocumentRootNode snapshot =
-        new JsonDocumentRootNode(nodeKey, firstChildKey, lastChildKey, childCount, descendantCount, hashFunction);
+    if (page != null) {
+      // Bound mode: read all fields from page
+      final long nk = this.nodeKey;
+      final JsonDocumentRootNode snapshot = new JsonDocumentRootNode(
+          nk,
+          readDeltaField(NodeFieldLayout.JDOCROOT_FIRST_CHILD_KEY, nk),
+          readDeltaField(NodeFieldLayout.JDOCROOT_LAST_CHILD_KEY, nk),
+          readSignedLongField(NodeFieldLayout.JDOCROOT_CHILD_COUNT),
+          readSignedLongField(NodeFieldLayout.JDOCROOT_DESCENDANT_COUNT),
+          hashFunction);
+      snapshot.hash = readLongField(NodeFieldLayout.JDOCROOT_HASH);
+      if (deweyIDBytes != null) {
+        snapshot.deweyIDBytes = deweyIDBytes.clone();
+      }
+      if (sirixDeweyID != null) {
+        snapshot.sirixDeweyID = sirixDeweyID;
+      }
+      return snapshot;
+    }
+    final JsonDocumentRootNode snapshot = new JsonDocumentRootNode(
+        nodeKey, firstChildKey, lastChildKey, childCount, descendantCount, hashFunction);
     snapshot.hash = this.hash;
     if (deweyIDBytes != null) {
       snapshot.deweyIDBytes = deweyIDBytes.clone();
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/json/NullNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/json/NullNode.java
index de0ab91fd..a946cab2b 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/json/NullNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/json/NullNode.java
@@ -31,9 +31,9 @@
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Objects;
 import io.sirix.access.ResourceConfiguration;
-import io.sirix.access.trx.node.HashType;
 import io.sirix.api.visitor.JsonNodeVisitor;
 import io.sirix.api.visitor.VisitResult;
+import io.sirix.node.Bytes;
 import io.sirix.node.ByteArrayBytesIn;
 import io.sirix.node.BytesIn;
 import io.sirix.node.BytesOut;
@@ -43,14 +43,14 @@
 import io.sirix.node.SirixDeweyID;
 
 import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
 import io.sirix.node.immutable.json.ImmutableNullNode;
-import io.sirix.node.layout.NodeKindLayout;
-import io.sirix.node.layout.SlotLayoutAccessors;
-import io.sirix.node.layout.StructuralField;
+import io.sirix.node.interfaces.FlyweightNode;
 import io.sirix.node.interfaces.Node;
-import io.sirix.node.interfaces.ReusableNodeProxy;
 import io.sirix.node.interfaces.StructNode;
 import io.sirix.node.interfaces.immutable.ImmutableJsonNode;
+import io.sirix.page.KeyValueLeafPage;
+import io.sirix.page.NodeFieldLayout;
 import io.sirix.settings.Fixed;
 import net.openhft.hashing.LongHashFunction;
 import org.checkerframework.checker.nullness.qual.NonNull;
@@ -59,13 +59,11 @@
 /**
  * JSON Null node.
  *
- * 

- * Uses primitive fields for efficient storage with delta+varint encoding.
- * 

- * 
+ * 
Uses primitive fields for efficient storage with delta+varint encoding.

+ *
  * @author Johannes Lichtenberger
  */
-public final class NullNode implements StructNode, ImmutableJsonNode, ReusableNodeProxy {
+public final class NullNode implements StructNode, ImmutableJsonNode, FlyweightNode {
 
   // Node identity (mutable for singleton reuse)
   private long nodeKey;
@@ -91,19 +89,52 @@ public final class NullNode implements StructNode, ImmutableJsonNode, ReusableNo
 
   // Lazy parsing state
   private Object lazySource;
-  private long lazyBaseOffset;
   private long lazyOffset;
   private boolean lazyFieldsParsed;
-  private boolean hasHash;
+  // ==================== FLYWEIGHT BINDING (LeanStore page-direct access) ====================
+
+  /** Page MemorySegment when bound (null = primitive mode). */
+  private MemorySegment page;
+
+  /** Absolute byte offset of this record in the page (after HEAP_START + heapOffset). */
+  private long recordBase;
+
+  /** Absolute byte offset where the data region starts (recordBase + 1 + FIELD_COUNT). */
+  private long dataRegionStart;
+
+  /** Slot index in the page directory (for re-serialization). */
+  private int slotIndex;
+
+  /** True if this node is a factory-managed write singleton (must not be stored in records[]). */
+  private boolean writeSingleton;
+
+  /** Owning page for resize-in-place on varint width changes. */
+  private KeyValueLeafPage ownerPage;
+
+  /** Pre-allocated offset array reused across serializations (zero-alloc hot path). */
+  private final int[] heapOffsets;
 
-  // Fixed-slot lazy support
-  private NodeKindLayout fixedSlotLayout;
+  private static final int FIELD_COUNT = NodeFieldLayout.NULL_VALUE_FIELD_COUNT;
+
+  /**
+   * Constructor for flyweight binding.
+   * All fields except nodeKey and hashFunction will be read from page memory after bind().
+   *
+   * @param nodeKey the node key
+   * @param hashFunction the hash function from resource config
+   */
+  public NullNode(long nodeKey, LongHashFunction hashFunction) {
+    this.nodeKey = nodeKey;
+    this.hashFunction = hashFunction;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
 
   /**
    * Primary constructor with all primitive fields.
    */
-  public NullNode(long nodeKey, long parentKey, int previousRevision, int lastModifiedRevision, long rightSiblingKey,
-      long leftSiblingKey, long hash, LongHashFunction hashFunction, byte[] deweyID) {
+  public NullNode(long nodeKey, long parentKey, int previousRevision,
+      int lastModifiedRevision, long rightSiblingKey, long leftSiblingKey, long hash,
+      LongHashFunction hashFunction, byte[] deweyID) {
     this.nodeKey = nodeKey;
     this.parentKey = parentKey;
     this.previousRevision = previousRevision;
@@ -114,13 +145,15 @@ public NullNode(long nodeKey, long parentKey, int previousRevision, int lastModi
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyID;
     this.lazyFieldsParsed = true;
+    this.heapOffsets = new int[FIELD_COUNT];
   }
 
   /**
    * Constructor with SirixDeweyID instead of byte array.
    */
-  public NullNode(long nodeKey, long parentKey, int previousRevision, int lastModifiedRevision, long rightSiblingKey,
-      long leftSiblingKey, long hash, LongHashFunction hashFunction, SirixDeweyID deweyID) {
+  public NullNode(long nodeKey, long parentKey, int previousRevision,
+      int lastModifiedRevision, long rightSiblingKey, long leftSiblingKey, long hash,
+      LongHashFunction hashFunction, SirixDeweyID deweyID) {
     this.nodeKey = nodeKey;
     this.parentKey = parentKey;
     this.previousRevision = previousRevision;
@@ -131,6 +164,184 @@ public NullNode(long nodeKey, long parentKey, int previousRevision, int lastModi
     this.hashFunction = hashFunction;
     this.sirixDeweyID = deweyID;
     this.lazyFieldsParsed = true;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
+
+  // ==================== FLYWEIGHT BIND/UNBIND ====================
+
+  /**
+   * Bind this node as a flyweight to a page MemorySegment.
+   * When bound, getters/setters read/write directly to page memory via the offset table.
+   *
+   * @param page       the page MemorySegment
+   * @param recordBase absolute byte offset of this record in the page
+   * @param nodeKey    the node key (for delta decoding)
+   * @param slotIndex  the slot index in the page directory
+   */
+  public void bind(final MemorySegment page, final long recordBase, final long nodeKey,
+      final int slotIndex) {
+    this.page = page;
+    this.recordBase = recordBase;
+    this.nodeKey = nodeKey;
+    this.slotIndex = slotIndex;
+    this.dataRegionStart = recordBase + 1 + FIELD_COUNT;
+    this.hash = 0;
+    this.lazyFieldsParsed = true; // No lazy state when bound
+    this.lazySource = null;
+  }
+
+  /**
+   * Unbind from page memory and materialize all fields into Java primitives.
+   * After unbind, the node operates in primitive mode.
+   */
+  public void unbind() {
+    if (page == null) {
+      return;
+    }
+    // Materialize all fields from page to Java primitives
+    final long nk = this.nodeKey;
+    this.parentKey = readDeltaField(NodeFieldLayout.NULLVAL_PARENT_KEY, nk);
+    this.rightSiblingKey = readDeltaField(NodeFieldLayout.NULLVAL_RIGHT_SIB_KEY, nk);
+    this.leftSiblingKey = readDeltaField(NodeFieldLayout.NULLVAL_LEFT_SIB_KEY, nk);
+    this.previousRevision = readSignedField(NodeFieldLayout.NULLVAL_PREV_REVISION);
+    this.lastModifiedRevision = readSignedField(NodeFieldLayout.NULLVAL_LAST_MOD_REVISION);
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  @Override
+  public void clearBinding() {
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  /** Check if this node is bound to a page MemorySegment. */
+  public boolean isBound() {
+    return page != null;
+  }
+
+  @Override
+  public boolean isBoundTo(final MemorySegment page) {
+    return this.page == page;
+  }
+
+  @Override
+  public int getSlotIndex() {
+    return slotIndex;
+  }
+
+  // ==================== FLYWEIGHT FIELD READ HELPERS ====================
+
+  private long readDeltaField(final int fieldIndex, final long baseKey) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeDeltaFromSegment(page, dataRegionStart + fieldOff, baseKey);
+  }
+
+  private int readSignedField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeSignedFromSegment(page, dataRegionStart + fieldOff);
+  }
+
+  // ==================== OWNER PAGE (for resize-in-place) ====================
+
+  @Override
+  public KeyValueLeafPage getOwnerPage() {
+    return ownerPage;
+  }
+
+  @Override
+  public void setOwnerPage(final KeyValueLeafPage ownerPage) {
+    this.ownerPage = ownerPage;
+  }
+
+  // ==================== SERIALIZE TO HEAP ====================
+
+  /**
+   * Encode a NullNode record directly to a MemorySegment from parameter values.
+   * Static -- reads nothing from any instance. Zero field intermediation.
+   *
+   * @param target      the target MemorySegment (reinterpreted slotted page)
+   * @param offset      absolute byte offset to write at
+   * @param heapOffsets pre-allocated offset array (reused, FIELD_COUNT elements)
+   * @param nodeKey     the node key (delta base for structural keys)
+   * @param parentKey   the parent node key
+   * @param rightSibKey the right sibling key
+   * @param leftSibKey  the left sibling key
+   * @param prevRev     the previous revision number
+   * @param lastModRev  the last modified revision number
+   * @return the total number of bytes written
+   */
+  public static int writeNewRecord(final MemorySegment target, final long offset,
+      final int[] heapOffsets, final long nodeKey,
+      final long parentKey, final long rightSibKey, final long leftSibKey,
+      final int prevRev, final int lastModRev) {
+    long pos = offset;
+
+    // Write nodeKind byte
+    target.set(ValueLayout.JAVA_BYTE, pos, NodeKind.NULL_VALUE.getId());
+    pos++;
+
+    // Reserve space for offset table
+    final long offsetTableStart = pos;
+    pos += FIELD_COUNT;
+
+    // Data region start
+    final long dataStart = pos;
+
+    // Field 0: parentKey (delta-varint)
+    heapOffsets[NodeFieldLayout.NULLVAL_PARENT_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, parentKey, nodeKey);
+
+    // Field 1: rightSiblingKey (delta-varint)
+    heapOffsets[NodeFieldLayout.NULLVAL_RIGHT_SIB_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, rightSibKey, nodeKey);
+
+    // Field 2: leftSiblingKey (delta-varint)
+    heapOffsets[NodeFieldLayout.NULLVAL_LEFT_SIB_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, leftSibKey, nodeKey);
+
+    // Field 3: previousRevision (signed varint)
+    heapOffsets[NodeFieldLayout.NULLVAL_PREV_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, prevRev);
+
+    // Field 4: lastModifiedRevision (signed varint)
+    heapOffsets[NodeFieldLayout.NULLVAL_LAST_MOD_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, lastModRev);
+
+    // Write offset table
+    for (int i = 0; i < FIELD_COUNT; i++) {
+      target.set(ValueLayout.JAVA_BYTE, offsetTableStart + i, (byte) heapOffsets[i]);
+    }
+
+    return (int) (pos - offset);
+  }
+
+  /**
+   * Serialize this node from Java fields. Delegates to static writeNewRecord.
+   */
+  public int serializeToHeap(final MemorySegment target, final long offset) {
+    if (!lazyFieldsParsed) {
+      parseLazyFields();
+    }
+    return writeNewRecord(target, offset, heapOffsets, nodeKey,
+        parentKey, rightSiblingKey, leftSiblingKey,
+        previousRevision, lastModifiedRevision);
+  }
+
+  /**
+   * Get the pre-allocated heap offsets array for use with static writeNewRecord.
+   */
+  public int[] getHeapOffsets() {
+    return heapOffsets;
+  }
+
+  /**
+   * Set DeweyID fields directly after creation, bypassing write-through.
+   * The DeweyID is already in the page trailer -- this just sets the Java cache fields.
+   */
+  public void setDeweyIDAfterCreation(final SirixDeweyID id, final byte[] bytes) {
+    this.sirixDeweyID = id;
+    this.deweyIDBytes = bytes;
   }
 
   @Override
@@ -145,16 +356,38 @@ public long getNodeKey() {
 
   @Override
   public long getParentKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.NULLVAL_PARENT_KEY, nodeKey);
+    }
     return parentKey;
   }
 
   public void setParentKey(final long parentKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.NULLVAL_PARENT_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(parentKey, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, parentKey, nodeKey);
+        return;
+      }
+      resizeParentKey(parentKey);
+      return;
+    }
     this.parentKey = parentKey;
   }
 
+  private void resizeParentKey(final long value) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.NULLVAL_PARENT_KEY, NodeFieldLayout.NULL_VALUE_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, value, nodeKey));
+  }
+
   @Override
   public boolean hasParent() {
-    return parentKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getParentKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
@@ -169,31 +402,83 @@ public void setTypeKey(final int typeKey) {
 
   @Override
   public void setDeweyID(final SirixDeweyID id) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.sirixDeweyID = id;
+      this.deweyIDBytes = null;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
     this.sirixDeweyID = id;
     this.deweyIDBytes = null;
   }
 
-  public void setDeweyIDBytes(final byte[] deweyIDBytes) {
-    this.deweyIDBytes = deweyIDBytes;
+  @Override
+  public void setDeweyIDBytes(final byte[] bytes) {
+    this.deweyIDBytes = bytes;
     this.sirixDeweyID = null;
   }
 
   @Override
   public void setPreviousRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.NULLVAL_PREV_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizePreviousRevision(revision);
+      return;
+    }
     this.previousRevision = revision;
   }
 
+  private void resizePreviousRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.NULLVAL_PREV_REVISION, NodeFieldLayout.NULL_VALUE_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+  }
+
   @Override
   public void setLastModifiedRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.NULLVAL_LAST_MOD_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizeLastModifiedRevision(revision);
+      return;
+    }
     this.lastModifiedRevision = revision;
   }
 
+  private void resizeLastModifiedRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.NULLVAL_LAST_MOD_REVISION, NodeFieldLayout.NULL_VALUE_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+  }
+
   @Override
   public long getHash() {
-    if (!lazyFieldsParsed) {
-      parseLazyFields();
+    if (hash != 0L) {
+      return hash;
+    }
+    if (hashFunction != null) {
+      return computeHash(Bytes.threadLocalHashBuffer());
     }
-    return hash;
+    return 0L;
   }
 
   @Override
@@ -204,39 +489,75 @@ public void setHash(final long hash) {
   @Override
   public long computeHash(final BytesOut bytes) {
     bytes.clear();
-    bytes.writeLong(getNodeKey()).writeLong(getParentKey()).writeByte(getKind().getId());
-
-    bytes.writeLong(getChildCount())
-         .writeLong(getDescendantCount())
-         .writeLong(getLeftSiblingKey())
-         .writeLong(getRightSiblingKey())
-         .writeLong(getFirstChildKey());
-
-    if (getLastChildKey() != Fixed.INVALID_KEY_FOR_TYPE_CHECK.getStandardProperty()) {
-      bytes.writeLong(getLastChildKey());
-    }
+    bytes.writeLong(getNodeKey())
+         .writeLong(getParentKey())
+         .writeByte(getKind().getId());
 
     return bytes.hashDirect(hashFunction);
   }
 
   @Override
   public long getRightSiblingKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.NULLVAL_RIGHT_SIB_KEY, nodeKey);
+    }
     return rightSiblingKey;
   }
 
   public void setRightSiblingKey(final long rightSibling) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.NULLVAL_RIGHT_SIB_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(rightSibling, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, rightSibling, nodeKey);
+        return;
+      }
+      resizeRightSiblingKey(rightSibling);
+      return;
+    }
     this.rightSiblingKey = rightSibling;
   }
 
+  private void resizeRightSiblingKey(final long value) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.NULLVAL_RIGHT_SIB_KEY, NodeFieldLayout.NULL_VALUE_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, value, nodeKey));
+  }
+
   @Override
   public long getLeftSiblingKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.NULLVAL_LEFT_SIB_KEY, nodeKey);
+    }
     return leftSiblingKey;
   }
 
   public void setLeftSiblingKey(final long leftSibling) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.NULLVAL_LEFT_SIB_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(leftSibling, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, leftSibling, nodeKey);
+        return;
+      }
+      resizeLeftSiblingKey(leftSibling);
+      return;
+    }
     this.leftSiblingKey = leftSibling;
   }
 
+  private void resizeLeftSiblingKey(final long value) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.NULLVAL_LEFT_SIB_KEY, NodeFieldLayout.NULL_VALUE_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, value, nodeKey));
+  }
+
   @Override
   public long getFirstChildKey() {
     return Fixed.NULL_NODE_KEY.getStandardProperty();
@@ -305,16 +626,19 @@ public void decrementDescendantCount() {
 
   @Override
   public boolean hasLeftSibling() {
-    return leftSiblingKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getLeftSiblingKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public boolean hasRightSibling() {
-    return rightSiblingKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getRightSiblingKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public int getPreviousRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.NULLVAL_PREV_REVISION);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
@@ -323,6 +647,9 @@ public int getPreviousRevisionNumber() {
 
   @Override
   public int getLastModifiedRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.NULLVAL_LAST_MOD_REVISION);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
@@ -339,7 +666,9 @@ public void setNodeKey(final long nodeKey) {
   }
 
   public void readFrom(final BytesIn source, final long nodeKey, final byte[] deweyId,
-      final LongHashFunction hashFunction, final ResourceConfiguration config) {
+                       final LongHashFunction hashFunction, final ResourceConfiguration config) {
+    // Unbind flyweight — ensures getters use Java fields, not stale page reference
+    this.page = null;
     this.nodeKey = nodeKey;
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyId;
@@ -354,37 +683,16 @@ public void readFrom(final BytesIn source, final long nodeKey, final byte[] d
     this.lazySource = source.getSource();
     this.lazyOffset = source.position();
     this.lazyFieldsParsed = false;
-    this.hasHash = config.hashType != HashType.NONE;
-
     this.previousRevision = 0;
     this.lastModifiedRevision = 0;
     this.hash = 0;
   }
 
-  public void bindFixedSlotLazy(final MemorySegment slotData, final long baseOffset, final NodeKindLayout layout) {
-    this.lazyBaseOffset = baseOffset;
-    this.lazySource = slotData;
-    this.fixedSlotLayout = layout;
-    this.lazyFieldsParsed = false;
-  }
-
   private void parseLazyFields() {
     if (lazyFieldsParsed) {
       return;
     }
 
-    if (fixedSlotLayout != null) {
-      final MemorySegment sd = (MemorySegment) lazySource;
-      final NodeKindLayout ly = fixedSlotLayout;
-      final long off = this.lazyBaseOffset;
-      this.previousRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.PREVIOUS_REVISION);
-      this.lastModifiedRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.LAST_MODIFIED_REVISION);
-      this.hash = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.HASH);
-      this.fixedSlotLayout = null;
-      this.lazyFieldsParsed = true;
-      return;
-    }
-
     if (lazySource == null) {
       lazyFieldsParsed = true;
       return;
@@ -403,20 +711,38 @@ private void parseLazyFields() {
 
     this.previousRevision = DeltaVarIntCodec.decodeSigned(bytesIn);
     this.lastModifiedRevision = DeltaVarIntCodec.decodeSigned(bytesIn);
-    if (hasHash) {
-      this.hash = bytesIn.readLong();
-    }
     this.lazyFieldsParsed = true;
   }
 
   public NullNode toSnapshot() {
+    if (page != null) {
+      // Bound mode: read all fields from page
+      return new NullNode(nodeKey,
+          readDeltaField(NodeFieldLayout.NULLVAL_PARENT_KEY, nodeKey),
+          readSignedField(NodeFieldLayout.NULLVAL_PREV_REVISION),
+          readSignedField(NodeFieldLayout.NULLVAL_LAST_MOD_REVISION),
+          readDeltaField(NodeFieldLayout.NULLVAL_RIGHT_SIB_KEY, nodeKey),
+          readDeltaField(NodeFieldLayout.NULLVAL_LEFT_SIB_KEY, nodeKey),
+          hash,
+          hashFunction,
+          getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
-    return new NullNode(nodeKey, parentKey, previousRevision, lastModifiedRevision, rightSiblingKey, leftSiblingKey,
-        hash, hashFunction, deweyIDBytes != null
-            ? deweyIDBytes.clone()
-            : null);
+    return new NullNode(nodeKey, parentKey, previousRevision, lastModifiedRevision,
+        rightSiblingKey, leftSiblingKey, hash, hashFunction,
+        getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null);
+  }
+
+  @Override
+  public boolean isWriteSingleton() {
+    return writeSingleton;
+  }
+
+  @Override
+  public void setWriteSingleton(final boolean writeSingleton) {
+    this.writeSingleton = writeSingleton;
   }
 
   @Override
@@ -462,6 +788,7 @@ public boolean equals(final Object obj) {
     if (!(obj instanceof final NullNode other))
       return false;
 
-    return nodeKey == other.nodeKey && parentKey == other.parentKey;
+    return nodeKey == other.nodeKey
+        && parentKey == other.parentKey;
   }
 }
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/json/NumberNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/json/NumberNode.java
index a2e7c8243..6d49c79f3 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/json/NumberNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/json/NumberNode.java
@@ -34,6 +34,7 @@
 import io.sirix.access.trx.node.HashType;
 import io.sirix.api.visitor.JsonNodeVisitor;
 import io.sirix.api.visitor.VisitResult;
+import io.sirix.node.Bytes;
 import io.sirix.node.ByteArrayBytesIn;
 import io.sirix.node.BytesIn;
 import io.sirix.node.BytesOut;
@@ -43,15 +44,15 @@
 import io.sirix.node.SirixDeweyID;
 
 import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
 import io.sirix.node.immutable.json.ImmutableNumberNode;
+import io.sirix.node.interfaces.FlyweightNode;
 import io.sirix.node.interfaces.Node;
-import io.sirix.node.layout.NodeKindLayout;
-import io.sirix.node.layout.SlotLayoutAccessors;
-import io.sirix.node.layout.StructuralField;
 import io.sirix.node.interfaces.NumericValueNode;
-import io.sirix.node.interfaces.ReusableNodeProxy;
 import io.sirix.node.interfaces.StructNode;
 import io.sirix.node.interfaces.immutable.ImmutableJsonNode;
+import io.sirix.page.KeyValueLeafPage;
+import io.sirix.page.NodeFieldLayout;
 import io.sirix.settings.Fixed;
 import net.openhft.hashing.LongHashFunction;
 import org.checkerframework.checker.nullness.qual.NonNull;
@@ -63,62 +64,83 @@
 /**
  * JSON Number node.
  *
- * 

- * Uses primitive fields for efficient storage with delta+varint encoding.
- * 

+ * 
Uses primitive fields for efficient storage with delta+varint encoding.

  * 
  * @author Johannes Lichtenberger
  */
-public final class NumberNode implements StructNode, ImmutableJsonNode, NumericValueNode, ReusableNodeProxy {
+public final class NumberNode implements StructNode, ImmutableJsonNode, NumericValueNode, FlyweightNode {
 
   // Node identity (mutable for singleton reuse)
   private long nodeKey;
-
+  
   // Mutable structural fields
   private long parentKey;
   private long rightSiblingKey;
   private long leftSiblingKey;
-
+  
   // Mutable revision tracking
   private int previousRevision;
   private int lastModifiedRevision;
-
+  
   // Mutable hash (computed on demand for value nodes)
   private long hash;
-
+  
   // Number value
   private Number value;
-
+  
   // Hash function for computing node hashes (mutable for singleton reuse)
   private LongHashFunction hashFunction;
-
+  
   // DeweyID support (lazily parsed)
   private SirixDeweyID sirixDeweyID;
   private byte[] deweyIDBytes;
 
   // Lazy parsing state (for singleton reuse optimization)
   // Two-stage lazy parsing: metadata (cheap) vs value (expensive Number allocation)
-  private Object lazySource; // Source for lazy parsing (MemorySegment or byte[])
-  private long lazyOffset; // Offset where lazy metadata fields start
-  private boolean metadataParsed; // Whether prevRev, lastModRev, hash are parsed
-  private boolean valueParsed; // Whether Number value is parsed
-  private boolean hasHash; // Whether hash is stored (from config)
-  private long valueOffset; // Offset where value starts (after metadata)
+  private Object lazySource;            // Source for lazy parsing (MemorySegment or byte[])
+  private long lazyOffset;              // Offset where lazy metadata fields start
+  private boolean metadataParsed;       // Whether prevRev, lastModRev, hash are parsed
+  private boolean valueParsed;          // Whether Number value is parsed
+  private boolean hasHash;              // Whether hash is stored (from config)
+  private long valueOffset;             // Offset where value starts (after metadata)
 
-  // Fixed-slot value encoding state (for read path via populateSingletonFromFixedSlot)
-  private boolean fixedValueEncoding; // Whether value comes from fixed-slot inline payload
-  private int fixedValueLength; // Length of inline payload bytes
+  // ==================== FLYWEIGHT BINDING (LeanStore page-direct access) ====================
+  private MemorySegment page;
+  private long recordBase;
+  private long dataRegionStart;
+  private int slotIndex;
 
-  // Fixed-slot lazy metadata support
-  private long lazyBaseOffset;
-  private NodeKindLayout fixedSlotLayout;
+  /** True if this node is a factory-managed write singleton (must not be stored in records[]). */
+  private boolean writeSingleton;
+
+  /** Owning page for resize-in-place on varint width changes. */
+  private KeyValueLeafPage ownerPage;
+
+  /** Pre-allocated offset array reused across serializations (zero-alloc hot path). */
+  private final int[] heapOffsets;
+
+  private static final int FIELD_COUNT = NodeFieldLayout.NUMBER_VALUE_FIELD_COUNT;
+
+  /**
+   * Constructor for flyweight binding.
+   * All fields except nodeKey and hashFunction will be read from page memory after bind().
+   *
+   * @param nodeKey the node key
+   * @param hashFunction the hash function from resource config
+   */
+  public NumberNode(long nodeKey, LongHashFunction hashFunction) {
+    this.nodeKey = nodeKey;
+    this.hashFunction = hashFunction;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
 
   /**
-   * Primary constructor with all primitive fields. All fields are already parsed - no lazy loading
-   * needed.
+   * Primary constructor with all primitive fields.
+   * All fields are already parsed - no lazy loading needed.
    */
-  public NumberNode(long nodeKey, long parentKey, int previousRevision, int lastModifiedRevision, long rightSiblingKey,
-      long leftSiblingKey, long hash, Number value, LongHashFunction hashFunction, byte[] deweyID) {
+  public NumberNode(long nodeKey, long parentKey, int previousRevision,
+      int lastModifiedRevision, long rightSiblingKey, long leftSiblingKey, long hash,
+      Number value, LongHashFunction hashFunction, byte[] deweyID) {
     this.nodeKey = nodeKey;
     this.parentKey = parentKey;
     this.previousRevision = previousRevision;
@@ -132,14 +154,16 @@ public NumberNode(long nodeKey, long parentKey, int previousRevision, int lastMo
     // Constructed with all values - mark as fully parsed
     this.metadataParsed = true;
     this.valueParsed = true;
+    this.heapOffsets = new int[FIELD_COUNT];
   }
 
   /**
-   * Constructor with SirixDeweyID instead of byte array. All fields are already parsed - no lazy
-   * loading needed.
+   * Constructor with SirixDeweyID instead of byte array.
+   * All fields are already parsed - no lazy loading needed.
    */
-  public NumberNode(long nodeKey, long parentKey, int previousRevision, int lastModifiedRevision, long rightSiblingKey,
-      long leftSiblingKey, long hash, Number value, LongHashFunction hashFunction, SirixDeweyID deweyID) {
+  public NumberNode(long nodeKey, long parentKey, int previousRevision,
+      int lastModifiedRevision, long rightSiblingKey, long leftSiblingKey, long hash,
+      Number value, LongHashFunction hashFunction, SirixDeweyID deweyID) {
     this.nodeKey = nodeKey;
     this.parentKey = parentKey;
     this.previousRevision = previousRevision;
@@ -153,6 +177,299 @@ public NumberNode(long nodeKey, long parentKey, int previousRevision, int lastMo
     // Constructed with all values - mark as fully parsed
     this.metadataParsed = true;
     this.valueParsed = true;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
+
+  // ==================== FLYWEIGHT BIND/UNBIND ====================
+
+  public void bind(final MemorySegment page, final long recordBase, final long nodeKey,
+      final int slotIndex) {
+    this.page = page;
+    this.recordBase = recordBase;
+    this.nodeKey = nodeKey;
+    this.slotIndex = slotIndex;
+    this.dataRegionStart = recordBase + 1 + FIELD_COUNT;
+    this.hash = 0;
+    this.metadataParsed = true;
+    this.valueParsed = false;
+    this.lazySource = null;
+  }
+
+  public void unbind() {
+    if (page == null) return;
+    final long nk = this.nodeKey;
+    this.parentKey = readDeltaField(NodeFieldLayout.NUMVAL_PARENT_KEY, nk);
+    this.rightSiblingKey = readDeltaField(NodeFieldLayout.NUMVAL_RIGHT_SIB_KEY, nk);
+    this.leftSiblingKey = readDeltaField(NodeFieldLayout.NUMVAL_LEFT_SIB_KEY, nk);
+    this.previousRevision = readSignedField(NodeFieldLayout.NUMVAL_PREV_REVISION);
+    this.lastModifiedRevision = readSignedField(NodeFieldLayout.NUMVAL_LAST_MOD_REVISION);
+    if (!valueParsed) {
+      readPayloadFromPage();
+    }
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  @Override
+  public void clearBinding() {
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  public boolean isBound() { return page != null; }
+
+  @Override
+  public boolean isBoundTo(final MemorySegment page) {
+    return this.page == page;
+  }
+
+  @Override
+  public int getSlotIndex() {
+    return slotIndex;
+  }
+
+  @Override
+  public int estimateSerializedSize() {
+    // 1 (nodeKind) + 6 (offset table) + ~30 (varint fields avg) + ~10 (number payload) = ~47
+    // Conservative upper bound without hash (was 56, minus 9 for removed 8-byte hash + 1-byte offset entry)
+    return 47;
+  }
+
+  // ==================== FLYWEIGHT FIELD READ HELPERS ====================
+
+  private long readDeltaField(final int fieldIndex, final long baseKey) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeDeltaFromSegment(page, dataRegionStart + fieldOff, baseKey);
+  }
+
+  private int readSignedField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeSignedFromSegment(page, dataRegionStart + fieldOff);
+  }
+
+  private long readLongField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.readLongFromSegment(page, (int) (dataRegionStart + fieldOff));
+  }
+
+  @Override
+  public KeyValueLeafPage getOwnerPage() {
+    return ownerPage;
+  }
+
+  @Override
+  public void setOwnerPage(final KeyValueLeafPage ownerPage) {
+    this.ownerPage = ownerPage;
+  }
+
+  /**
+   * Read the Number payload from page memory when bound.
+   * Uses the flyweight format written by {@link #serializeNumberToSegment}.
+   */
+  private void readPayloadFromPage() {
+    final int payloadFieldOff = page.get(ValueLayout.JAVA_BYTE,
+        recordBase + 1 + NodeFieldLayout.NUMVAL_PAYLOAD) & 0xFF;
+    final long payloadStart = dataRegionStart + payloadFieldOff;
+    this.value = deserializeNumberFromSegment(page, payloadStart);
+    this.valueParsed = true;
+  }
+
+  /**
+   * Deserialize a Number value directly from a MemorySegment.
+   * Format must match {@link #serializeNumberToSegment} exactly:
+   * 
+   *   Type 0 = Integer (zigzag varint)
+   *   Type 1 = Long (zigzag varlong)
+   *   Type 2 = Float (4 bytes, native endian raw bits)
+   *   Type 3 = Double (8 bytes, native endian raw bits)
+   *   Type 4 = BigDecimal (varint scale + varint byte-length + bytes)
+   *   Type 5 = BigInteger (varint byte-length + bytes)
+   * 

+   *
+   * @param segment the MemorySegment containing the serialized number
+   * @param offset  the byte offset of the number type byte
+   * @return the deserialized Number
+   */
+  static Number deserializeNumberFromSegment(final MemorySegment segment, final long offset) {
+    final byte valueType = segment.get(ValueLayout.JAVA_BYTE, offset);
+    long pos = offset + 1;
+
+    return switch (valueType) {
+      case 0 -> // Integer (zigzag varint)
+          DeltaVarIntCodec.decodeSignedFromSegment(segment, pos);
+      case 1 -> // Long (zigzag varlong)
+          DeltaVarIntCodec.decodeSignedLongFromSegment(segment, pos);
+      case 2 -> // Float (4 bytes raw bits, native endian)
+          Float.intBitsToFloat(segment.get(ValueLayout.JAVA_INT_UNALIGNED, pos));
+      case 3 -> // Double (8 bytes raw bits, native endian)
+          Double.longBitsToDouble(segment.get(ValueLayout.JAVA_LONG_UNALIGNED, pos));
+      case 4 -> { // BigDecimal (varint scale + varint byte-length + bytes)
+        final int scale = DeltaVarIntCodec.decodeSignedFromSegment(segment, pos);
+        final int scaleWidth = DeltaVarIntCodec.readSignedVarintWidth(segment, pos);
+        pos += scaleWidth;
+        final int bytesLen = DeltaVarIntCodec.decodeSignedFromSegment(segment, pos);
+        final int bytesLenWidth = DeltaVarIntCodec.readSignedVarintWidth(segment, pos);
+        pos += bytesLenWidth;
+        final byte[] bytes = new byte[bytesLen];
+        MemorySegment.copy(segment, ValueLayout.JAVA_BYTE, pos, bytes, 0, bytesLen);
+        yield new BigDecimal(new BigInteger(bytes), scale);
+      }
+      case 5 -> { // BigInteger (varint byte-length + bytes)
+        final int bytesLen = DeltaVarIntCodec.decodeSignedFromSegment(segment, pos);
+        final int bytesLenWidth = DeltaVarIntCodec.readSignedVarintWidth(segment, pos);
+        pos += bytesLenWidth;
+        final byte[] bytes = new byte[bytesLen];
+        MemorySegment.copy(segment, ValueLayout.JAVA_BYTE, pos, bytes, 0, bytesLen);
+        yield new BigInteger(bytes);
+      }
+      default -> throw new IllegalStateException("Unknown flyweight number type: " + valueType);
+    };
+  }
+
+  // ==================== SERIALIZE TO HEAP ====================
+
+  /**
+   * Encode a NumberNode record directly to a MemorySegment from parameter values.
+   * Static -- reads nothing from any instance. Zero field intermediation.
+   *
+   * @param target      the target MemorySegment (reinterpreted slotted page)
+   * @param offset      absolute byte offset to write at
+   * @param heapOffsets pre-allocated offset array (reused, FIELD_COUNT elements)
+   * @param nodeKey     the node key (delta base for structural keys)
+   * @param parentKey   the parent node key
+   * @param rightSibKey the right sibling key
+   * @param leftSibKey  the left sibling key
+   * @param prevRev     the previous revision number
+   * @param lastModRev  the last modified revision number
+   * @param value       the Number value
+   * @return the total number of bytes written
+   */
+  public static int writeNewRecord(final MemorySegment target, final long offset,
+      final int[] heapOffsets, final long nodeKey,
+      final long parentKey, final long rightSibKey, final long leftSibKey,
+      final int prevRev, final int lastModRev, final Number value) {
+    long pos = offset;
+
+    // Write nodeKind byte
+    target.set(ValueLayout.JAVA_BYTE, pos, NodeKind.NUMBER_VALUE.getId());
+    pos++;
+
+    // Reserve space for offset table
+    final long offsetTableStart = pos;
+    pos += FIELD_COUNT;
+
+    // Data region start
+    final long dataStart = pos;
+
+    // Field 0: parentKey (delta-varint)
+    heapOffsets[NodeFieldLayout.NUMVAL_PARENT_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, parentKey, nodeKey);
+
+    // Field 1: rightSiblingKey (delta-varint)
+    heapOffsets[NodeFieldLayout.NUMVAL_RIGHT_SIB_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, rightSibKey, nodeKey);
+
+    // Field 2: leftSiblingKey (delta-varint)
+    heapOffsets[NodeFieldLayout.NUMVAL_LEFT_SIB_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, leftSibKey, nodeKey);
+
+    // Field 3: previousRevision (signed varint)
+    heapOffsets[NodeFieldLayout.NUMVAL_PREV_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, prevRev);
+
+    // Field 4: lastModifiedRevision (signed varint)
+    heapOffsets[NodeFieldLayout.NUMVAL_LAST_MOD_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, lastModRev);
+
+    // Field 5: payload (Number type dispatch)
+    heapOffsets[NodeFieldLayout.NUMVAL_PAYLOAD] = (int) (pos - dataStart);
+    pos += serializeNumberToSegment(target, pos, value);
+
+    // Write offset table
+    for (int i = 0; i < FIELD_COUNT; i++) {
+      target.set(ValueLayout.JAVA_BYTE, offsetTableStart + i, (byte) heapOffsets[i]);
+    }
+
+    return (int) (pos - offset);
+  }
+
+  /**
+   * Serialize this node from Java fields. Delegates to static writeNewRecord.
+   */
+  public int serializeToHeap(final MemorySegment target, final long offset) {
+    if (!metadataParsed) parseMetadataFields();
+    if (!valueParsed) parseValueField();
+    return writeNewRecord(target, offset, heapOffsets, nodeKey,
+        parentKey, rightSiblingKey, leftSiblingKey,
+        previousRevision, lastModifiedRevision, value);
+  }
+
+  /**
+   * Get the pre-allocated heap offsets array for use with static writeNewRecord.
+   */
+  public int[] getHeapOffsets() {
+    return heapOffsets;
+  }
+
+  /**
+   * Set DeweyID fields directly after creation, bypassing write-through.
+   * The DeweyID is already in the page trailer -- this just sets the Java cache fields.
+   */
+  public void setDeweyIDAfterCreation(final SirixDeweyID id, final byte[] bytes) {
+    this.sirixDeweyID = id;
+    this.deweyIDBytes = bytes;
+  }
+
+  /**
+   * Serialize a Number value directly to a MemorySegment.
+   * Format: [numberType:1][numberData:variable]
+   */
+  private static int serializeNumberToSegment(final MemorySegment target, final long offset,
+      final Number number) {
+    long pos = offset;
+    switch (number) {
+      case Integer intVal -> {
+        target.set(ValueLayout.JAVA_BYTE, pos, (byte) 0);
+        pos++;
+        pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, intVal);
+      }
+      case Long longVal -> {
+        target.set(ValueLayout.JAVA_BYTE, pos, (byte) 1);
+        pos++;
+        pos += DeltaVarIntCodec.writeSignedLongToSegment(target, pos, longVal);
+      }
+      case Float floatVal -> {
+        target.set(ValueLayout.JAVA_BYTE, pos, (byte) 2);
+        pos++;
+        target.set(ValueLayout.JAVA_INT_UNALIGNED, pos, Float.floatToRawIntBits(floatVal));
+        pos += Float.BYTES;
+      }
+      case Double doubleVal -> {
+        target.set(ValueLayout.JAVA_BYTE, pos, (byte) 3);
+        pos++;
+        target.set(ValueLayout.JAVA_LONG_UNALIGNED, pos, Double.doubleToRawLongBits(doubleVal));
+        pos += Double.BYTES;
+      }
+      case BigDecimal bigDecimalVal -> {
+        target.set(ValueLayout.JAVA_BYTE, pos, (byte) 4);
+        pos++;
+        final byte[] bytes = bigDecimalVal.unscaledValue().toByteArray();
+        pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, bigDecimalVal.scale());
+        pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, bytes.length);
+        MemorySegment.copy(bytes, 0, target, ValueLayout.JAVA_BYTE, pos, bytes.length);
+        pos += bytes.length;
+      }
+      case BigInteger bigIntegerVal -> {
+        target.set(ValueLayout.JAVA_BYTE, pos, (byte) 5);
+        pos++;
+        final byte[] bytes = bigIntegerVal.toByteArray();
+        pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, bytes.length);
+        MemorySegment.copy(bytes, 0, target, ValueLayout.JAVA_BYTE, pos, bytes.length);
+        pos += bytes.length;
+      }
+      default -> throw new IllegalStateException("Unexpected number type: " + number.getClass());
+    }
+    return (int) (pos - offset);
   }
 
   @Override
@@ -167,16 +484,38 @@ public long getNodeKey() {
 
   @Override
   public long getParentKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.NUMVAL_PARENT_KEY, nodeKey);
+    }
     return parentKey;
   }
 
   public void setParentKey(final long parentKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.NUMVAL_PARENT_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(parentKey, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, parentKey, nodeKey);
+        return;
+      }
+      resizeParentKey(parentKey);
+      return;
+    }
     this.parentKey = parentKey;
   }
 
+  private void resizeParentKey(final long parentKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.NUMVAL_PARENT_KEY, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, parentKey, nodeKey));
+  }
+
   @Override
   public boolean hasParent() {
-    return parentKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getParentKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
@@ -191,26 +530,83 @@ public void setTypeKey(final int typeKey) {
 
   @Override
   public void setDeweyID(final SirixDeweyID id) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.sirixDeweyID = id;
+      this.deweyIDBytes = null;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
     this.sirixDeweyID = id;
     this.deweyIDBytes = null;
   }
 
+  @Override
+  public void setDeweyIDBytes(final byte[] bytes) {
+    this.deweyIDBytes = bytes;
+    this.sirixDeweyID = null;
+  }
+
   @Override
   public void setPreviousRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.NUMVAL_PREV_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizePreviousRevision(revision);
+      return;
+    }
     this.previousRevision = revision;
   }
 
+  private void resizePreviousRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.NUMVAL_PREV_REVISION, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+  }
+
   @Override
   public void setLastModifiedRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.NUMVAL_LAST_MOD_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizeLastModifiedRevision(revision);
+      return;
+    }
     this.lastModifiedRevision = revision;
   }
 
+  private void resizeLastModifiedRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.NUMVAL_LAST_MOD_REVISION, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+  }
+
   @Override
   public long getHash() {
-    if (!metadataParsed) {
-      parseMetadataFields();
+    if (hash != 0L) {
+      return hash;
+    }
+    if (hashFunction != null) {
+      return computeHash(Bytes.threadLocalHashBuffer());
     }
-    return hash;
+    return 0L;
   }
 
   @Override
@@ -221,17 +617,9 @@ public void setHash(final long hash) {
   @Override
   public long computeHash(final BytesOut bytes) {
     bytes.clear();
-    bytes.writeLong(getNodeKey()).writeLong(getParentKey()).writeByte(getKind().getId());
-
-    bytes.writeLong(getChildCount())
-         .writeLong(getDescendantCount())
-         .writeLong(getLeftSiblingKey())
-         .writeLong(getRightSiblingKey())
-         .writeLong(getFirstChildKey());
-
-    if (getLastChildKey() != Fixed.INVALID_KEY_FOR_TYPE_CHECK.getStandardProperty()) {
-      bytes.writeLong(getLastChildKey());
-    }
+    bytes.writeLong(getNodeKey())
+         .writeLong(getParentKey())
+         .writeByte(getKind().getId());
 
     final Number number = getValue();
     switch (number) {
@@ -249,27 +637,71 @@ public long computeHash(final BytesOut bytes) {
 
   @Override
   public long getRightSiblingKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.NUMVAL_RIGHT_SIB_KEY, nodeKey);
+    }
     return rightSiblingKey;
   }
 
   public void setRightSiblingKey(final long rightSibling) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.NUMVAL_RIGHT_SIB_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(rightSibling, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, rightSibling, nodeKey);
+        return;
+      }
+      resizeRightSiblingKey(rightSibling);
+      return;
+    }
     this.rightSiblingKey = rightSibling;
   }
 
+  private void resizeRightSiblingKey(final long rightSibling) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.NUMVAL_RIGHT_SIB_KEY, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, rightSibling, nodeKey));
+  }
+
   @Override
   public long getLeftSiblingKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.NUMVAL_LEFT_SIB_KEY, nodeKey);
+    }
     return leftSiblingKey;
   }
 
   public void setLeftSiblingKey(final long leftSibling) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.NUMVAL_LEFT_SIB_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(leftSibling, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, leftSibling, nodeKey);
+        return;
+      }
+      resizeLeftSiblingKey(leftSibling);
+      return;
+    }
     this.leftSiblingKey = leftSibling;
   }
 
+  private void resizeLeftSiblingKey(final long leftSibling) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.NUMVAL_LEFT_SIB_KEY, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, leftSibling, nodeKey));
+  }
+
   @Override
   public long getFirstChildKey() {
     return Fixed.NULL_NODE_KEY.getStandardProperty();
   }
-
+  
   public void setFirstChildKey(final long firstChild) {
     // Value nodes are leaf nodes - no-op
   }
@@ -278,7 +710,7 @@ public void setFirstChildKey(final long firstChild) {
   public long getLastChildKey() {
     return Fixed.NULL_NODE_KEY.getStandardProperty();
   }
-
+  
   public void setLastChildKey(final long lastChild) {
     // Value nodes are leaf nodes - no-op
   }
@@ -287,7 +719,7 @@ public void setLastChildKey(final long lastChild) {
   public long getChildCount() {
     return 0;
   }
-
+  
   public void setChildCount(final long childCount) {
     // Value nodes are leaf nodes - no-op
   }
@@ -296,22 +728,32 @@ public void setChildCount(final long childCount) {
   public long getDescendantCount() {
     return 0;
   }
-
+  
   public void setDescendantCount(final long descendantCount) {
     // Value nodes are leaf nodes - no-op
   }
 
   public Number getValue() {
-    if (!valueParsed) {
+    if (page != null && !valueParsed) {
+      readPayloadFromPage();
+    } else if (!valueParsed) {
       parseValueField();
     }
     return value;
   }
 
   public void setValue(final Number value) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.value = value;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
+    if (page != null) unbind();
     this.value = value;
-    this.fixedValueEncoding = false;
-    this.valueParsed = true;
   }
 
   @Override
@@ -346,16 +788,19 @@ public void decrementDescendantCount() {
 
   @Override
   public boolean hasLeftSibling() {
-    return leftSiblingKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getLeftSiblingKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public boolean hasRightSibling() {
-    return rightSiblingKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getRightSiblingKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public int getPreviousRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.NUMVAL_PREV_REVISION);
+    }
     if (!metadataParsed) {
       parseMetadataFields();
     }
@@ -364,6 +809,9 @@ public int getPreviousRevisionNumber() {
 
   @Override
   public int getLastModifiedRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.NUMVAL_LAST_MOD_REVISION);
+    }
     if (!metadataParsed) {
       parseMetadataFields();
     }
@@ -379,18 +827,15 @@ public void setNodeKey(final long nodeKey) {
     this.nodeKey = nodeKey;
   }
 
-  public void setDeweyIDBytes(final byte[] deweyIDBytes) {
-    this.deweyIDBytes = deweyIDBytes;
-    this.sirixDeweyID = null;
-  }
-
   /**
-   * Populate this node from a BytesIn source for singleton reuse. LAZY OPTIMIZATION: Only parses
-   * structural fields immediately. Two-stage lazy parsing: metadata (cheap) vs value (expensive
-   * Number allocation).
+   * Populate this node from a BytesIn source for singleton reuse.
+   * LAZY OPTIMIZATION: Only parses structural fields immediately.
+   * Two-stage lazy parsing: metadata (cheap) vs value (expensive Number allocation).
    */
   public void readFrom(final BytesIn source, final long nodeKey, final byte[] deweyId,
-      final LongHashFunction hashFunction, final ResourceConfiguration config) {
+                       final LongHashFunction hashFunction, final ResourceConfiguration config) {
+    // Unbind flyweight — ensures getters use Java fields, not stale page reference
+    this.page = null;
     this.nodeKey = nodeKey;
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyId;
@@ -408,73 +853,36 @@ public void readFrom(final BytesIn source, final long nodeKey, final byte[] d
     this.valueParsed = false;
     this.hasHash = config.hashType != HashType.NONE;
     this.valueOffset = 0;
-
+    
     // Initialize lazy fields to defaults (will be populated on demand)
     this.previousRevision = 0;
     this.lastModifiedRevision = 0;
     this.hash = 0;
     this.value = null;
   }
-
+  
   /**
-   * Populate this singleton from fixed-slot inline payload (zero allocation). Sets up lazy value
-   * parsing from the fixed-slot MemorySegment. CRITICAL: Resets hash to 0 — caller MUST call
-   * setHash() AFTER this method.
-   *
-   * @param source the slot data (MemorySegment) containing inline payload
-   * @param valueOffset byte offset within source where payload bytes start
-   * @param valueLength length of payload bytes
+   * Parse metadata fields on demand (cheap - just varints and optionally a long).
+   * Called by getters that access prevRev, lastModRev, or hash.
    */
-  public void setLazyNumberValue(final Object source, final long valueOffset, final int valueLength) {
-    this.lazySource = source;
-    this.valueOffset = valueOffset;
-    this.metadataParsed = true;
-    this.valueParsed = false;
-    this.fixedValueEncoding = true;
-    this.fixedValueLength = valueLength;
-    this.value = null;
-    this.hash = 0L;
-  }
-
-  public void bindFixedSlotLazy(final MemorySegment slotData, final long baseOffset, final NodeKindLayout layout) {
-    this.lazyBaseOffset = baseOffset;
-    this.fixedSlotLayout = layout;
-    this.metadataParsed = false;
-  }
-
   private void parseMetadataFields() {
     if (metadataParsed) {
       return;
     }
-
-    if (fixedSlotLayout != null) {
-      final MemorySegment sd = (MemorySegment) lazySource;
-      final NodeKindLayout ly = fixedSlotLayout;
-      final long off = this.lazyBaseOffset;
-      this.previousRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.PREVIOUS_REVISION);
-      this.lastModifiedRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.LAST_MODIFIED_REVISION);
-      this.hash = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.HASH);
-      this.fixedSlotLayout = null;
-      this.metadataParsed = true;
-      return;
-    }
-
+    
     if (lazySource == null) {
       metadataParsed = true;
       return;
     }
-
+    
     BytesIn bytesIn = createBytesIn(lazyOffset);
-
+    
     this.previousRevision = DeltaVarIntCodec.decodeSigned(bytesIn);
     this.lastModifiedRevision = DeltaVarIntCodec.decodeSigned(bytesIn);
-    if (hasHash) {
-      this.hash = bytesIn.readLong();
-    }
     this.valueOffset = bytesIn.position();
     this.metadataParsed = true;
   }
-
+  
   /**
    * Parse value field on demand (expensive - may allocate BigDecimal/BigInteger).
    */
@@ -482,33 +890,21 @@ private void parseValueField() {
     if (valueParsed) {
       return;
     }
-
-    // Fixed-slot inline payload path (from setLazyNumberValue)
-    if (fixedValueEncoding) {
-      if (fixedValueLength > 0) {
-        final BytesIn bytesIn = createBytesIn(valueOffset);
-        this.value = NodeKind.deserializeNumber(bytesIn);
-      } else {
-        this.value = 0;
-      }
-      this.valueParsed = true;
-      return;
-    }
-
+    
     if (!metadataParsed) {
       parseMetadataFields();
     }
-
+    
     if (lazySource == null) {
       valueParsed = true;
       return;
     }
-
-    final BytesIn bytesIn = createBytesIn(valueOffset);
+    
+    BytesIn bytesIn = createBytesIn(valueOffset);
     this.value = NodeKind.deserializeNumber(bytesIn);
     this.valueParsed = true;
   }
-
+  
   private BytesIn createBytesIn(long offset) {
     if (lazySource instanceof MemorySegment segment) {
       var bytesIn = new MemorySegmentBytesIn(segment);
@@ -524,10 +920,25 @@ private BytesIn createBytesIn(long offset) {
   }
 
   /**
-   * Create a deep copy snapshot of this node. Forces parsing of all lazy fields since snapshot must
-   * be independent.
+   * Create a deep copy snapshot of this node.
+   * Forces parsing of all lazy fields since snapshot must be independent.
    */
   public NumberNode toSnapshot() {
+    if (page != null) {
+      // Bound mode: read all fields from page
+      if (!valueParsed) {
+        readPayloadFromPage();
+      }
+      return new NumberNode(nodeKey,
+          readDeltaField(NodeFieldLayout.NUMVAL_PARENT_KEY, nodeKey),
+          readSignedField(NodeFieldLayout.NUMVAL_PREV_REVISION),
+          readSignedField(NodeFieldLayout.NUMVAL_LAST_MOD_REVISION),
+          readDeltaField(NodeFieldLayout.NUMVAL_RIGHT_SIB_KEY, nodeKey),
+          readDeltaField(NodeFieldLayout.NUMVAL_LEFT_SIB_KEY, nodeKey),
+          hash,
+          value, hashFunction,
+          getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null);
+    }
     // Force parse all lazy fields for snapshot (must be complete and independent)
     if (!metadataParsed) {
       parseMetadataFields();
@@ -535,10 +946,19 @@ public NumberNode toSnapshot() {
     if (!valueParsed) {
       parseValueField();
     }
-    return new NumberNode(nodeKey, parentKey, previousRevision, lastModifiedRevision, rightSiblingKey, leftSiblingKey,
-        hash, value, hashFunction, deweyIDBytes != null
-            ? deweyIDBytes.clone()
-            : null);
+    return new NumberNode(nodeKey, parentKey, previousRevision, lastModifiedRevision,
+        rightSiblingKey, leftSiblingKey, hash, value, hashFunction,
+        getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null);
+  }
+
+  @Override
+  public boolean isWriteSingleton() {
+    return writeSingleton;
+  }
+
+  @Override
+  public void setWriteSingleton(final boolean writeSingleton) {
+    this.writeSingleton = writeSingleton;
   }
 
   @Override
@@ -585,6 +1005,8 @@ public boolean equals(final Object obj) {
     if (!(obj instanceof final NumberNode other))
       return false;
 
-    return nodeKey == other.nodeKey && parentKey == other.parentKey && Objects.equal(value, other.value);
+    return nodeKey == other.nodeKey
+        && parentKey == other.parentKey
+        && Objects.equal(value, other.value);
   }
 }
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/json/ObjectBooleanNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/json/ObjectBooleanNode.java
index 5e473dce3..94ae290c8 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/json/ObjectBooleanNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/json/ObjectBooleanNode.java
@@ -31,9 +31,9 @@
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Objects;
 import io.sirix.access.ResourceConfiguration;
-import io.sirix.access.trx.node.HashType;
 import io.sirix.api.visitor.JsonNodeVisitor;
 import io.sirix.api.visitor.VisitResult;
+import io.sirix.node.Bytes;
 import io.sirix.node.ByteArrayBytesIn;
 import io.sirix.node.BytesIn;
 import io.sirix.node.BytesOut;
@@ -43,15 +43,15 @@
 import io.sirix.node.SirixDeweyID;
 
 import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
 import io.sirix.node.immutable.json.ImmutableObjectBooleanNode;
-import io.sirix.node.layout.NodeKindLayout;
-import io.sirix.node.layout.SlotLayoutAccessors;
-import io.sirix.node.layout.StructuralField;
 import io.sirix.node.interfaces.BooleanValueNode;
+import io.sirix.node.interfaces.FlyweightNode;
 import io.sirix.node.interfaces.Node;
-import io.sirix.node.interfaces.ReusableNodeProxy;
 import io.sirix.node.interfaces.StructNode;
+import io.sirix.page.KeyValueLeafPage;
 import io.sirix.node.interfaces.immutable.ImmutableJsonNode;
+import io.sirix.page.NodeFieldLayout;
 import io.sirix.settings.Fixed;
 import net.openhft.hashing.LongHashFunction;
 import org.checkerframework.checker.nullness.qual.NonNull;
@@ -60,13 +60,11 @@
 /**
  * JSON Object Boolean node (direct child of ObjectKeyNode, no siblings).
  *
- * 

- * Uses primitive fields for efficient storage with delta+varint encoding.
- * 

- * 
+ * 
Uses primitive fields for efficient storage with delta+varint encoding.

+ *
  * @author Johannes Lichtenberger
  */
-public final class ObjectBooleanNode implements StructNode, ImmutableJsonNode, BooleanValueNode, ReusableNodeProxy {
+public final class ObjectBooleanNode implements StructNode, ImmutableJsonNode, BooleanValueNode, FlyweightNode {
 
   // Node identity (mutable for singleton reuse)
   private long nodeKey;
@@ -93,19 +91,54 @@ public final class ObjectBooleanNode implements StructNode, ImmutableJsonNode, B
 
   // Lazy parsing state (single-stage since boolean value is cheap)
   private Object lazySource;
-  private long lazyBaseOffset;
   private long lazyOffset;
   private boolean lazyFieldsParsed;
-  private boolean hasHash;
 
-  // Fixed-slot lazy support
-  private NodeKindLayout fixedSlotLayout;
+
+  // ==================== FLYWEIGHT BINDING (LeanStore page-direct access) ====================
+
+  /** Page MemorySegment when bound (null = primitive mode). */
+  private MemorySegment page;
+
+  /** Absolute byte offset of this record in the page (after HEAP_START + heapOffset). */
+  private long recordBase;
+
+  /** Absolute byte offset where the data region starts (recordBase + 1 + FIELD_COUNT). */
+  private long dataRegionStart;
+
+  /** Slot index in the page directory (for re-serialization). */
+  private int slotIndex;
+
+  /** True if this node is a factory-managed write singleton (must not be stored in records[]). */
+  private boolean writeSingleton;
+
+  /** Owning page for resize-in-place on varint width changes. */
+  private KeyValueLeafPage ownerPage;
+
+  /** Pre-allocated offset array reused across serializations (zero-alloc hot path). */
+  private final int[] heapOffsets;
+
+  private static final int FIELD_COUNT = NodeFieldLayout.OBJECT_BOOLEAN_VALUE_FIELD_COUNT;
+
+  /**
+   * Constructor for flyweight binding.
+   * All fields except nodeKey and hashFunction will be read from page memory after bind().
+   *
+   * @param nodeKey the node key
+   * @param hashFunction the hash function from resource config
+   */
+  public ObjectBooleanNode(long nodeKey, LongHashFunction hashFunction) {
+    this.nodeKey = nodeKey;
+    this.hashFunction = hashFunction;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
 
   /**
    * Primary constructor with all primitive fields.
    */
-  public ObjectBooleanNode(long nodeKey, long parentKey, int previousRevision, int lastModifiedRevision, long hash,
-      boolean value, LongHashFunction hashFunction, byte[] deweyID) {
+  public ObjectBooleanNode(long nodeKey, long parentKey, int previousRevision,
+      int lastModifiedRevision, long hash, boolean value,
+      LongHashFunction hashFunction, byte[] deweyID) {
     this.nodeKey = nodeKey;
     this.parentKey = parentKey;
     this.previousRevision = previousRevision;
@@ -115,13 +148,15 @@ public ObjectBooleanNode(long nodeKey, long parentKey, int previousRevision, int
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyID;
     this.lazyFieldsParsed = true;
+    this.heapOffsets = new int[FIELD_COUNT];
   }
 
   /**
    * Constructor with SirixDeweyID instead of byte array.
    */
-  public ObjectBooleanNode(long nodeKey, long parentKey, int previousRevision, int lastModifiedRevision, long hash,
-      boolean value, LongHashFunction hashFunction, SirixDeweyID deweyID) {
+  public ObjectBooleanNode(long nodeKey, long parentKey, int previousRevision,
+      int lastModifiedRevision, long hash, boolean value,
+      LongHashFunction hashFunction, SirixDeweyID deweyID) {
     this.nodeKey = nodeKey;
     this.parentKey = parentKey;
     this.previousRevision = previousRevision;
@@ -131,6 +166,201 @@ public ObjectBooleanNode(long nodeKey, long parentKey, int previousRevision, int
     this.hashFunction = hashFunction;
     this.sirixDeweyID = deweyID;
     this.lazyFieldsParsed = true;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
+
+  // ==================== STATIC WRITE / HEAP OFFSETS / DEWEYID ====================
+
+  /**
+   * Encode an ObjectBooleanNode record directly to a MemorySegment from parameter values.
+   * Static -- reads nothing from any instance. Zero field intermediation.
+   *
+   * @param target     the target MemorySegment (reinterpreted slotted page)
+   * @param offset     absolute byte offset to write at
+   * @param heapOffsets pre-allocated offset array (reused, FIELD_COUNT elements)
+   * @param nodeKey    the node key (delta base for structural keys)
+   * @param parentKey  the parent node key
+   * @param prevRev    the previous revision number
+   * @param lastModRev the last modified revision number
+   * @param boolValue  the boolean value
+   * @return the total number of bytes written
+   */
+  public static int writeNewRecord(final MemorySegment target, final long offset,
+      final int[] heapOffsets, final long nodeKey,
+      final long parentKey, final int prevRev, final int lastModRev,
+      final boolean boolValue) {
+    long pos = offset;
+
+    // Write nodeKind byte
+    target.set(ValueLayout.JAVA_BYTE, pos, NodeKind.OBJECT_BOOLEAN_VALUE.getId());
+    pos++;
+
+    // Reserve space for offset table
+    final long offsetTableStart = pos;
+    pos += FIELD_COUNT;
+
+    // Data region start
+    final long dataStart = pos;
+
+    // Field 0: parentKey (delta-varint)
+    heapOffsets[NodeFieldLayout.OBJBOOLVAL_PARENT_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, parentKey, nodeKey);
+
+    // Field 1: previousRevision (signed varint)
+    heapOffsets[NodeFieldLayout.OBJBOOLVAL_PREV_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, prevRev);
+
+    // Field 2: lastModifiedRevision (signed varint)
+    heapOffsets[NodeFieldLayout.OBJBOOLVAL_LAST_MOD_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, lastModRev);
+
+    // Field 3: value (1 byte boolean)
+    heapOffsets[NodeFieldLayout.OBJBOOLVAL_VALUE] = (int) (pos - dataStart);
+    target.set(ValueLayout.JAVA_BYTE, pos, (byte) (boolValue ? 1 : 0));
+    pos += 1;
+
+    // Write offset table
+    for (int i = 0; i < FIELD_COUNT; i++) {
+      target.set(ValueLayout.JAVA_BYTE, offsetTableStart + i, (byte) heapOffsets[i]);
+    }
+
+    return (int) (pos - offset);
+  }
+
+  /**
+   * Get the pre-allocated heap offsets array for use with static writeNewRecord.
+   */
+  public int[] getHeapOffsets() {
+    return heapOffsets;
+  }
+
+  /**
+   * Set DeweyID fields directly after creation, bypassing write-through.
+   * The DeweyID is already in the page trailer -- this just sets the Java cache fields.
+   */
+  public void setDeweyIDAfterCreation(final SirixDeweyID id, final byte[] bytes) {
+    this.sirixDeweyID = id;
+    this.deweyIDBytes = bytes;
+  }
+
+  // ==================== FLYWEIGHT BIND/UNBIND ====================
+
+  /**
+   * Bind this node as a flyweight to a page MemorySegment.
+   * When bound, getters/setters read/write directly to page memory via the offset table.
+   *
+   * @param page       the page MemorySegment
+   * @param recordBase absolute byte offset of this record in the page
+   * @param nodeKey    the node key (for delta decoding)
+   * @param slotIndex  the slot index in the page directory
+   */
+  public void bind(final MemorySegment page, final long recordBase, final long nodeKey,
+      final int slotIndex) {
+    this.page = page;
+    this.recordBase = recordBase;
+    this.nodeKey = nodeKey;
+    this.slotIndex = slotIndex;
+    this.dataRegionStart = recordBase + 1 + FIELD_COUNT;
+    this.hash = 0;
+    this.lazyFieldsParsed = true; // No lazy state when bound
+    this.lazySource = null;
+  }
+
+  /**
+   * Unbind from page memory and materialize all fields into Java primitives.
+   * After unbind, the node operates in primitive mode.
+   */
+  public void unbind() {
+    if (page == null) {
+      return;
+    }
+    // Materialize all fields from page to Java primitives
+    final long nk = this.nodeKey;
+    this.parentKey = readDeltaField(NodeFieldLayout.OBJBOOLVAL_PARENT_KEY, nk);
+    this.previousRevision = readSignedField(NodeFieldLayout.OBJBOOLVAL_PREV_REVISION);
+    this.lastModifiedRevision = readSignedField(NodeFieldLayout.OBJBOOLVAL_LAST_MOD_REVISION);
+    this.value = readByteField(NodeFieldLayout.OBJBOOLVAL_VALUE) != 0;
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  @Override
+  public void clearBinding() {
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  /** Check if this node is bound to a page MemorySegment. */
+  public boolean isBound() {
+    return page != null;
+  }
+
+  @Override
+  public boolean isBoundTo(final MemorySegment page) {
+    return this.page == page;
+  }
+
+  @Override
+  public int getSlotIndex() {
+    return slotIndex;
+  }
+
+  // ==================== FLYWEIGHT FIELD READ HELPERS ====================
+
+  private long readDeltaField(final int fieldIndex, final long baseKey) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeDeltaFromSegment(page, dataRegionStart + fieldOff, baseKey);
+  }
+
+  private int readSignedField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeSignedFromSegment(page, dataRegionStart + fieldOff);
+  }
+
+  private byte readByteField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return page.get(ValueLayout.JAVA_BYTE, dataRegionStart + fieldOff);
+  }
+
+  /**
+   * Resize a single field via raw-copy on the owning slotted page.
+   * Avoids the full unbind-to-primitives + re-serialize round-trip.
+   *
+   * @param fieldIndex the field index in the offset table (e.g. {@code OBJBOOLVAL_PARENT_KEY})
+   * @param encoder    writes the new field value at the target offset
+   */
+  private void resizeRecordField(final int fieldIndex,
+      final DeltaVarIntCodec.FieldEncoder encoder) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex, fieldIndex, FIELD_COUNT, encoder);
+  }
+
+  // ==================== OWNER PAGE (for resize-in-place) ====================
+
+  @Override
+  public KeyValueLeafPage getOwnerPage() {
+    return ownerPage;
+  }
+
+  @Override
+  public void setOwnerPage(final KeyValueLeafPage ownerPage) {
+    this.ownerPage = ownerPage;
+  }
+
+  // ==================== SERIALIZE TO HEAP ====================
+
+  /**
+   * Serialize this node from Java fields. Delegates to static writeNewRecord.
+   *
+   * @param target the target MemorySegment
+   * @param offset the absolute byte offset to write at
+   * @return the total number of bytes written
+   */
+  public int serializeToHeap(final MemorySegment target, final long offset) {
+    if (!lazyFieldsParsed) {
+      parseLazyFields();
+    }
+    return writeNewRecord(target, offset, heapOffsets, nodeKey,
+        parentKey, previousRevision, lastModifiedRevision, value);
   }
 
   @Override
@@ -145,16 +375,33 @@ public long getNodeKey() {
 
   @Override
   public long getParentKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.OBJBOOLVAL_PARENT_KEY, nodeKey);
+    }
     return parentKey;
   }
 
   public void setParentKey(final long parentKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJBOOLVAL_PARENT_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(parentKey, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, parentKey, nodeKey);
+        return;
+      }
+      resizeRecordField(NodeFieldLayout.OBJBOOLVAL_PARENT_KEY,
+          (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, parentKey, nodeKey));
+      return;
+    }
     this.parentKey = parentKey;
   }
 
   @Override
   public boolean hasParent() {
-    return parentKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getParentKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
@@ -169,31 +416,73 @@ public void setTypeKey(final int typeKey) {
 
   @Override
   public void setDeweyID(final SirixDeweyID id) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.sirixDeweyID = id;
+      this.deweyIDBytes = null;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
     this.sirixDeweyID = id;
     this.deweyIDBytes = null;
   }
 
-  public void setDeweyIDBytes(final byte[] deweyIDBytes) {
-    this.deweyIDBytes = deweyIDBytes;
+  @Override
+  public void setDeweyIDBytes(final byte[] bytes) {
+    this.deweyIDBytes = bytes;
     this.sirixDeweyID = null;
   }
 
   @Override
   public void setPreviousRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJBOOLVAL_PREV_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizeRecordField(NodeFieldLayout.OBJBOOLVAL_PREV_REVISION,
+          (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+      return;
+    }
     this.previousRevision = revision;
   }
 
   @Override
   public void setLastModifiedRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJBOOLVAL_LAST_MOD_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizeRecordField(NodeFieldLayout.OBJBOOLVAL_LAST_MOD_REVISION,
+          (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+      return;
+    }
     this.lastModifiedRevision = revision;
   }
 
   @Override
   public long getHash() {
-    if (!lazyFieldsParsed) {
-      parseLazyFields();
+    if (hash != 0L) {
+      return hash;
     }
-    return hash;
+    if (hashFunction != null) {
+      return computeHash(Bytes.threadLocalHashBuffer());
+    }
+    return 0L;
   }
 
   @Override
@@ -204,7 +493,9 @@ public void setHash(final long hash) {
   @Override
   public long computeHash(final BytesOut bytes) {
     bytes.clear();
-    bytes.writeLong(getNodeKey()).writeLong(getParentKey()).writeByte(getKind().getId());
+    bytes.writeLong(getNodeKey())
+         .writeLong(getParentKey())
+         .writeByte(getKind().getId());
 
     bytes.writeLong(getChildCount())
          .writeLong(getDescendantCount())
@@ -276,6 +567,9 @@ public void setDescendantCount(final long descendantCount) {
   }
 
   public boolean getValue() {
+    if (page != null) {
+      return readByteField(NodeFieldLayout.OBJBOOLVAL_VALUE) != 0;
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
@@ -283,6 +577,13 @@ public boolean getValue() {
   }
 
   public void setValue(final boolean value) {
+    if (page != null) {
+      // Boolean is always 1 byte, always fits in-place
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJBOOLVAL_VALUE) & 0xFF;
+      page.set(ValueLayout.JAVA_BYTE, dataRegionStart + fieldOff, (byte) (value ? 1 : 0));
+      return;
+    }
     this.value = value;
   }
 
@@ -320,6 +621,9 @@ public boolean hasRightSibling() {
 
   @Override
   public int getPreviousRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.OBJBOOLVAL_PREV_REVISION);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
@@ -328,6 +632,9 @@ public int getPreviousRevisionNumber() {
 
   @Override
   public int getLastModifiedRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.OBJBOOLVAL_LAST_MOD_REVISION);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
@@ -344,7 +651,9 @@ public void setNodeKey(final long nodeKey) {
   }
 
   public void readFrom(final BytesIn source, final long nodeKey, final byte[] deweyId,
-      final LongHashFunction hashFunction, final ResourceConfiguration config) {
+                       final LongHashFunction hashFunction, final ResourceConfiguration config) {
+    // Unbind flyweight — ensures getters use Java fields, not stale page reference
+    this.page = null;
     this.nodeKey = nodeKey;
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyId;
@@ -357,38 +666,17 @@ public void readFrom(final BytesIn source, final long nodeKey, final byte[] d
     this.lazySource = source.getSource();
     this.lazyOffset = source.position();
     this.lazyFieldsParsed = false;
-    this.hasHash = config.hashType != HashType.NONE;
-
     this.previousRevision = 0;
     this.lastModifiedRevision = 0;
     this.value = false;
     this.hash = 0;
   }
 
-  public void bindFixedSlotLazy(final MemorySegment slotData, final long baseOffset, final NodeKindLayout layout) {
-    this.lazyBaseOffset = baseOffset;
-    this.lazySource = slotData;
-    this.fixedSlotLayout = layout;
-    this.lazyFieldsParsed = false;
-  }
-
   private void parseLazyFields() {
     if (lazyFieldsParsed) {
       return;
     }
 
-    if (fixedSlotLayout != null) {
-      final MemorySegment sd = (MemorySegment) lazySource;
-      final NodeKindLayout ly = fixedSlotLayout;
-      final long off = this.lazyBaseOffset;
-      this.previousRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.PREVIOUS_REVISION);
-      this.lastModifiedRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.LAST_MODIFIED_REVISION);
-      this.hash = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.HASH);
-      this.fixedSlotLayout = null;
-      this.lazyFieldsParsed = true;
-      return;
-    }
-
     if (lazySource == null) {
       lazyFieldsParsed = true;
       return;
@@ -408,20 +696,37 @@ private void parseLazyFields() {
     this.previousRevision = DeltaVarIntCodec.decodeSigned(bytesIn);
     this.lastModifiedRevision = DeltaVarIntCodec.decodeSigned(bytesIn);
     this.value = bytesIn.readBoolean();
-    if (hasHash) {
-      this.hash = bytesIn.readLong();
-    }
     this.lazyFieldsParsed = true;
   }
 
   public ObjectBooleanNode toSnapshot() {
+    if (page != null) {
+      // Bound mode: read all fields from page
+      return new ObjectBooleanNode(nodeKey,
+          readDeltaField(NodeFieldLayout.OBJBOOLVAL_PARENT_KEY, nodeKey),
+          readSignedField(NodeFieldLayout.OBJBOOLVAL_PREV_REVISION),
+          readSignedField(NodeFieldLayout.OBJBOOLVAL_LAST_MOD_REVISION),
+          hash,
+          readByteField(NodeFieldLayout.OBJBOOLVAL_VALUE) != 0,
+          hashFunction,
+          getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
-    return new ObjectBooleanNode(nodeKey, parentKey, previousRevision, lastModifiedRevision, hash, value, hashFunction,
-        deweyIDBytes != null
-            ? deweyIDBytes.clone()
-            : null);
+    return new ObjectBooleanNode(nodeKey, parentKey, previousRevision, lastModifiedRevision,
+        hash, value, hashFunction,
+        getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null);
+  }
+
+  @Override
+  public boolean isWriteSingleton() {
+    return writeSingleton;
+  }
+
+  @Override
+  public void setWriteSingleton(final boolean writeSingleton) {
+    this.writeSingleton = writeSingleton;
   }
 
   @Override
@@ -466,6 +771,8 @@ public boolean equals(final Object obj) {
     if (!(obj instanceof final ObjectBooleanNode other))
       return false;
 
-    return nodeKey == other.nodeKey && parentKey == other.parentKey && value == other.value;
+    return nodeKey == other.nodeKey
+        && parentKey == other.parentKey
+        && value == other.value;
   }
 }
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/json/ObjectKeyNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/json/ObjectKeyNode.java
index 5cdcb5737..f9e8de1c6 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/json/ObjectKeyNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/json/ObjectKeyNode.java
@@ -43,15 +43,16 @@
 import io.sirix.node.SirixDeweyID;
 
 import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
 import io.sirix.node.immutable.json.ImmutableObjectKeyNode;
-import io.sirix.node.layout.NodeKindLayout;
-import io.sirix.node.layout.SlotLayoutAccessors;
-import io.sirix.node.layout.StructuralField;
+import io.sirix.node.interfaces.FlyweightNode;
 import io.sirix.node.interfaces.NameNode;
 import io.sirix.node.interfaces.Node;
-import io.sirix.node.interfaces.ReusableNodeProxy;
 import io.sirix.node.interfaces.StructNode;
 import io.sirix.node.interfaces.immutable.ImmutableJsonNode;
+import io.sirix.page.KeyValueLeafPage;
+import io.sirix.page.NodeFieldLayout;
+import io.sirix.page.PageLayout;
 import io.sirix.settings.Fixed;
 import net.openhft.hashing.LongHashFunction;
 import org.checkerframework.checker.index.qual.NonNegative;
@@ -60,58 +61,91 @@
 /**
  * Node representing an object key/field.
  *
- * 

- * Uses primitive fields for efficient storage with delta+varint encoding.
- * 

+ * 
Uses primitive fields for efficient storage with delta+varint encoding.

  */
-public final class ObjectKeyNode implements StructNode, NameNode, ImmutableJsonNode, ReusableNodeProxy {
+public final class ObjectKeyNode implements StructNode, NameNode, ImmutableJsonNode, FlyweightNode {
 
   // Node identity (mutable for singleton reuse)
   private long nodeKey;
-
+  
   // Mutable structural fields
   private long parentKey;
   private long pathNodeKey;
   private long rightSiblingKey;
   private long leftSiblingKey;
   private long firstChildKey;
-
+  
   // Name key (hash of the name string)
   private int nameKey;
-
+  
   // Mutable revision tracking
   private int previousRevision;
   private int lastModifiedRevision;
-
+  
   // Mutable hash and descendant count
   private long hash;
   private long descendantCount;
-
+  
   // Hash function for computing node hashes (mutable for singleton reuse)
   private LongHashFunction hashFunction;
-
+  
   // DeweyID support (lazily parsed)
   private SirixDeweyID sirixDeweyID;
   private byte[] deweyIDBytes;
-
+  
   // Cache for name (not serialized, only nameKey is)
   private QNm cachedName;
 
   // Lazy parsing state
   private Object lazySource;
-  private long lazyBaseOffset;
   private long lazyOffset;
   private boolean lazyFieldsParsed;
   private boolean hasHash;
 
-  // Fixed-slot lazy support
-  private NodeKindLayout fixedSlotLayout;
+  // ==================== FLYWEIGHT BINDING (LeanStore page-direct access) ====================
+
+  /** Page MemorySegment when bound (null = primitive mode). */
+  private MemorySegment page;
+
+  /** Absolute byte offset of this record in the page (after HEAP_START + heapOffset). */
+  private long recordBase;
+
+  /** Absolute byte offset where the data region starts (recordBase + 1 + FIELD_COUNT). */
+  private long dataRegionStart;
+
+  /** Slot index in the page directory (for re-serialization). */
+  private int slotIndex;
+
+  /** True if this node is a factory-managed write singleton (must not be stored in records[]). */
+  private boolean writeSingleton;
+
+  /** Owning page for resize-in-place on varint width changes. */
+  private KeyValueLeafPage ownerPage;
+
+  /** Pre-allocated offset array reused across serializations (zero-alloc hot path). */
+  private final int[] heapOffsets;
+
+  private static final int FIELD_COUNT = NodeFieldLayout.OBJECT_KEY_FIELD_COUNT;
+
+  /**
+   * Constructor for flyweight binding.
+   * All fields except nodeKey and hashFunction will be read from page memory after bind().
+   *
+   * @param nodeKey the node key
+   * @param hashFunction the hash function from resource config
+   */
+  public ObjectKeyNode(long nodeKey, LongHashFunction hashFunction) {
+    this.nodeKey = nodeKey;
+    this.hashFunction = hashFunction;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
 
   /**
    * Primary constructor with all primitive fields.
    */
-  public ObjectKeyNode(long nodeKey, long parentKey, long pathNodeKey, int previousRevision, int lastModifiedRevision,
-      long rightSiblingKey, long leftSiblingKey, long firstChildKey, int nameKey, long descendantCount, long hash,
+  public ObjectKeyNode(long nodeKey, long parentKey, long pathNodeKey, int previousRevision,
+      int lastModifiedRevision, long rightSiblingKey, long leftSiblingKey, long firstChildKey,
+      int nameKey, long descendantCount, long hash,
       LongHashFunction hashFunction, byte[] deweyID) {
     this.nodeKey = nodeKey;
     this.parentKey = parentKey;
@@ -127,13 +161,15 @@ public ObjectKeyNode(long nodeKey, long parentKey, long pathNodeKey, int previou
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyID;
     this.lazyFieldsParsed = true;
+    this.heapOffsets = new int[FIELD_COUNT];
   }
 
   /**
    * Constructor with SirixDeweyID instead of byte array.
    */
-  public ObjectKeyNode(long nodeKey, long parentKey, long pathNodeKey, int previousRevision, int lastModifiedRevision,
-      long rightSiblingKey, long leftSiblingKey, long firstChildKey, int nameKey, long descendantCount, long hash,
+  public ObjectKeyNode(long nodeKey, long parentKey, long pathNodeKey, int previousRevision,
+      int lastModifiedRevision, long rightSiblingKey, long leftSiblingKey, long firstChildKey,
+      int nameKey, long descendantCount, long hash,
       LongHashFunction hashFunction, SirixDeweyID deweyID) {
     this.nodeKey = nodeKey;
     this.parentKey = parentKey;
@@ -149,6 +185,228 @@ public ObjectKeyNode(long nodeKey, long parentKey, long pathNodeKey, int previou
     this.hashFunction = hashFunction;
     this.sirixDeweyID = deweyID;
     this.lazyFieldsParsed = true;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
+
+  // ==================== FLYWEIGHT BIND/UNBIND ====================
+
+  /**
+   * Bind this node as a flyweight to a page MemorySegment.
+   * When bound, getters/setters read/write directly to page memory via the offset table.
+   *
+   * @param page       the page MemorySegment
+   * @param recordBase absolute byte offset of this record in the page
+   * @param nodeKey    the node key (for delta decoding)
+   * @param slotIndex  the slot index in the page directory
+   */
+  public void bind(final MemorySegment page, final long recordBase, final long nodeKey,
+      final int slotIndex) {
+    this.page = page;
+    this.recordBase = recordBase;
+    this.nodeKey = nodeKey;
+    this.slotIndex = slotIndex;
+    this.dataRegionStart = recordBase + 1 + FIELD_COUNT;
+    this.lazyFieldsParsed = true; // No lazy state when bound
+    this.lazySource = null;
+  }
+
+  /**
+   * Unbind from page memory and materialize all fields into Java primitives.
+   * After unbind, the node operates in primitive mode.
+   */
+  public void unbind() {
+    if (page == null) {
+      return;
+    }
+    // Materialize all fields from page to Java primitives
+    final long nk = this.nodeKey;
+    this.parentKey = readDeltaField(NodeFieldLayout.OBJKEY_PARENT_KEY, nk);
+    this.rightSiblingKey = readDeltaField(NodeFieldLayout.OBJKEY_RIGHT_SIB_KEY, nk);
+    this.leftSiblingKey = readDeltaField(NodeFieldLayout.OBJKEY_LEFT_SIB_KEY, nk);
+    this.firstChildKey = readDeltaField(NodeFieldLayout.OBJKEY_FIRST_CHILD_KEY, nk);
+    this.nameKey = readSignedField(NodeFieldLayout.OBJKEY_NAME_KEY);
+    this.pathNodeKey = readDeltaField(NodeFieldLayout.OBJKEY_PATH_NODE_KEY, nk);
+    this.previousRevision = readSignedField(NodeFieldLayout.OBJKEY_PREV_REVISION);
+    this.lastModifiedRevision = readSignedField(NodeFieldLayout.OBJKEY_LAST_MOD_REVISION);
+    this.hash = readLongField(NodeFieldLayout.OBJKEY_HASH);
+    this.descendantCount = readSignedLongField(NodeFieldLayout.OBJKEY_DESCENDANT_COUNT);
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  @Override
+  public void clearBinding() {
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  /** Check if this node is bound to a page MemorySegment. */
+  public boolean isBound() {
+    return page != null;
+  }
+
+  @Override
+  public boolean isBoundTo(final MemorySegment page) {
+    return this.page == page;
+  }
+
+  @Override
+  public int getSlotIndex() {
+    return slotIndex;
+  }
+
+  // ==================== FLYWEIGHT FIELD READ HELPERS ====================
+
+  private long readDeltaField(final int fieldIndex, final long baseKey) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeDeltaFromSegment(page, dataRegionStart + fieldOff, baseKey);
+  }
+
+  private int readSignedField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeSignedFromSegment(page, dataRegionStart + fieldOff);
+  }
+
+  private long readSignedLongField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeSignedLongFromSegment(page, dataRegionStart + fieldOff);
+  }
+
+  private long readLongField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.readLongFromSegment(page, (int) (dataRegionStart + fieldOff));
+  }
+
+  // ==================== OWNER PAGE (for resize-in-place) ====================
+
+  @Override
+  public KeyValueLeafPage getOwnerPage() {
+    return ownerPage;
+  }
+
+  @Override
+  public void setOwnerPage(final KeyValueLeafPage ownerPage) {
+    this.ownerPage = ownerPage;
+  }
+
+  // ==================== SERIALIZE TO HEAP ====================
+
+  /**
+   * Encode an ObjectKeyNode record directly to a MemorySegment from parameter values.
+   * Static -- reads nothing from any instance. Zero field intermediation.
+   *
+   * @param target          the target MemorySegment (reinterpreted slotted page)
+   * @param offset          absolute byte offset to write at
+   * @param heapOffsets     pre-allocated offset array (reused, FIELD_COUNT elements)
+   * @param nodeKey         the node key (delta base for structural keys)
+   * @param parentKey       the parent node key
+   * @param rightSibKey     the right sibling key
+   * @param leftSibKey      the left sibling key
+   * @param firstChildKey   the first child key
+   * @param nameKey         the name key (hash of the name string)
+   * @param pathNodeKey     the path node key
+   * @param prevRev         the previous revision number
+   * @param lastModRev      the last modified revision number
+   * @param hash            the hash value
+   * @param descendantCount the descendant count
+   * @return the total number of bytes written
+   */
+  public static int writeNewRecord(final MemorySegment target, final long offset,
+      final int[] heapOffsets, final long nodeKey,
+      final long parentKey, final long rightSibKey, final long leftSibKey,
+      final long firstChildKey, final int nameKey, final long pathNodeKey,
+      final int prevRev, final int lastModRev, final long hash,
+      final long descendantCount) {
+    long pos = offset;
+
+    // Write nodeKind byte
+    target.set(ValueLayout.JAVA_BYTE, pos, NodeKind.OBJECT_KEY.getId());
+    pos++;
+
+    // Reserve space for offset table
+    final long offsetTableStart = pos;
+    pos += FIELD_COUNT;
+
+    // Data region start
+    final long dataStart = pos;
+
+    // Field 0: parentKey (delta-varint)
+    heapOffsets[NodeFieldLayout.OBJKEY_PARENT_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, parentKey, nodeKey);
+
+    // Field 1: rightSiblingKey (delta-varint)
+    heapOffsets[NodeFieldLayout.OBJKEY_RIGHT_SIB_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, rightSibKey, nodeKey);
+
+    // Field 2: leftSiblingKey (delta-varint)
+    heapOffsets[NodeFieldLayout.OBJKEY_LEFT_SIB_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, leftSibKey, nodeKey);
+
+    // Field 3: firstChildKey (delta-varint)
+    heapOffsets[NodeFieldLayout.OBJKEY_FIRST_CHILD_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, firstChildKey, nodeKey);
+
+    // Field 4: nameKey (signed varint)
+    heapOffsets[NodeFieldLayout.OBJKEY_NAME_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, nameKey);
+
+    // Field 5: pathNodeKey (delta-varint)
+    heapOffsets[NodeFieldLayout.OBJKEY_PATH_NODE_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, pathNodeKey, nodeKey);
+
+    // Field 6: previousRevision (signed varint)
+    heapOffsets[NodeFieldLayout.OBJKEY_PREV_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, prevRev);
+
+    // Field 7: lastModifiedRevision (signed varint)
+    heapOffsets[NodeFieldLayout.OBJKEY_LAST_MOD_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, lastModRev);
+
+    // Field 8: hash (fixed 8 bytes)
+    heapOffsets[NodeFieldLayout.OBJKEY_HASH] = (int) (pos - dataStart);
+    DeltaVarIntCodec.writeLongToSegment(target, pos, hash);
+    pos += Long.BYTES;
+
+    // Field 9: descendantCount (signed long varint)
+    heapOffsets[NodeFieldLayout.OBJKEY_DESCENDANT_COUNT] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedLongToSegment(target, pos, descendantCount);
+
+    // Write offset table
+    for (int i = 0; i < FIELD_COUNT; i++) {
+      target.set(ValueLayout.JAVA_BYTE, offsetTableStart + i, (byte) heapOffsets[i]);
+    }
+
+    return (int) (pos - offset);
+  }
+
+  /**
+   * Serialize this node from Java fields. Delegates to static writeNewRecord.
+   */
+  public int serializeToHeap(final MemorySegment target, final long offset) {
+    if (!lazyFieldsParsed) {
+      parseLazyFields();
+    }
+    return writeNewRecord(target, offset, heapOffsets, nodeKey,
+        parentKey, rightSiblingKey, leftSiblingKey,
+        firstChildKey, nameKey, pathNodeKey,
+        previousRevision, lastModifiedRevision,
+        hash, descendantCount);
+  }
+
+  /**
+   * Get the pre-allocated heap offsets array for use with static writeNewRecord.
+   */
+  public int[] getHeapOffsets() {
+    return heapOffsets;
+  }
+
+  /**
+   * Set DeweyID fields directly after creation, bypassing write-through.
+   * The DeweyID is already in the page trailer -- this just sets the Java cache fields.
+   */
+  public void setDeweyIDAfterCreation(final SirixDeweyID id, final byte[] bytes) {
+    this.sirixDeweyID = id;
+    this.deweyIDBytes = bytes;
   }
 
   @Override
@@ -163,16 +421,38 @@ public long getNodeKey() {
 
   @Override
   public long getParentKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.OBJKEY_PARENT_KEY, nodeKey);
+    }
     return parentKey;
   }
 
   public void setParentKey(final long parentKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJKEY_PARENT_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(parentKey, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, parentKey, nodeKey);
+        return;
+      }
+      resizeParentKey(parentKey);
+      return;
+    }
     this.parentKey = parentKey;
   }
 
+  private void resizeParentKey(final long value) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.OBJKEY_PARENT_KEY, NodeFieldLayout.OBJECT_KEY_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, value, nodeKey));
+  }
+
   @Override
   public boolean hasParent() {
-    return parentKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getParentKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
@@ -187,27 +467,79 @@ public void setTypeKey(final int typeKey) {
 
   @Override
   public void setDeweyID(final SirixDeweyID id) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.sirixDeweyID = id;
+      this.deweyIDBytes = null;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
     this.sirixDeweyID = id;
     this.deweyIDBytes = null;
   }
 
-  public void setDeweyIDBytes(final byte[] deweyIDBytes) {
-    this.deweyIDBytes = deweyIDBytes;
+  @Override
+  public void setDeweyIDBytes(final byte[] bytes) {
+    this.deweyIDBytes = bytes;
     this.sirixDeweyID = null;
   }
 
   @Override
   public void setPreviousRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJKEY_PREV_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizePreviousRevision(revision);
+      return;
+    }
     this.previousRevision = revision;
   }
 
+  private void resizePreviousRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.OBJKEY_PREV_REVISION, NodeFieldLayout.OBJECT_KEY_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+  }
+
   @Override
   public void setLastModifiedRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJKEY_LAST_MOD_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizeLastModifiedRevision(revision);
+      return;
+    }
     this.lastModifiedRevision = revision;
   }
 
+  private void resizeLastModifiedRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.OBJKEY_LAST_MOD_REVISION, NodeFieldLayout.OBJECT_KEY_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+  }
+
   @Override
   public long getHash() {
+    if (page != null) {
+      return readLongField(NodeFieldLayout.OBJKEY_HASH);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
@@ -216,13 +548,22 @@ public long getHash() {
 
   @Override
   public void setHash(final long hash) {
+    if (page != null) {
+      // Hash is ALWAYS in-place (fixed 8 bytes)
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJKEY_HASH) & 0xFF;
+      DeltaVarIntCodec.writeLongToSegment(page, dataRegionStart + fieldOff, hash);
+      return;
+    }
     this.hash = hash;
   }
 
   @Override
   public long computeHash(BytesOut bytes) {
     bytes.clear();
-    bytes.writeLong(getNodeKey()).writeLong(getParentKey()).writeByte(getKind().getId());
+    bytes.writeLong(getNodeKey())
+         .writeLong(getParentKey())
+         .writeByte(getKind().getId());
 
     bytes.writeLong(getDescendantCount())
          .writeLong(getLeftSiblingKey())
@@ -239,6 +580,9 @@ public long computeHash(BytesOut bytes) {
   }
 
   public int getNameKey() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.OBJKEY_NAME_KEY);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
@@ -246,9 +590,28 @@ public int getNameKey() {
   }
 
   public void setNameKey(final int nameKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJKEY_NAME_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(nameKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, nameKey);
+        return;
+      }
+      resizeNameKey(nameKey);
+      return;
+    }
     this.nameKey = nameKey;
   }
 
+  private void resizeNameKey(final int nameKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.OBJKEY_NAME_KEY, NodeFieldLayout.OBJECT_KEY_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, nameKey));
+  }
+
   public QNm getName() {
     return cachedName;
   }
@@ -257,13 +620,9 @@ public void setName(final String name) {
     this.cachedName = new QNm(name);
   }
 
-  public void clearCachedName() {
-    this.cachedName = null;
-  }
-
   // NameNode interface methods
   public int getLocalNameKey() {
-    return nameKey;
+    return getNameKey();
   }
 
   public int getPrefixKey() {
@@ -283,10 +642,32 @@ public void setURIKey(final int uriKey) {
   }
 
   public void setLocalNameKey(final int localNameKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJKEY_NAME_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(localNameKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, localNameKey);
+        return;
+      }
+      resizeLocalNameKey(localNameKey);
+      return;
+    }
     this.nameKey = localNameKey;
   }
 
+  private void resizeLocalNameKey(final int localNameKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.OBJKEY_NAME_KEY, NodeFieldLayout.OBJECT_KEY_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, localNameKey));
+  }
+
   public long getPathNodeKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.OBJKEY_PATH_NODE_KEY, nodeKey);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
@@ -294,40 +675,125 @@ public long getPathNodeKey() {
   }
 
   public void setPathNodeKey(final @NonNegative long pathNodeKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJKEY_PATH_NODE_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(pathNodeKey, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, pathNodeKey, nodeKey);
+        return;
+      }
+      resizePathNodeKey(pathNodeKey);
+      return;
+    }
     this.pathNodeKey = pathNodeKey;
   }
 
+  private void resizePathNodeKey(final long value) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.OBJKEY_PATH_NODE_KEY, NodeFieldLayout.OBJECT_KEY_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, value, nodeKey));
+  }
+
   @Override
   public long getRightSiblingKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.OBJKEY_RIGHT_SIB_KEY, nodeKey);
+    }
     return rightSiblingKey;
   }
 
   public void setRightSiblingKey(final long rightSibling) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJKEY_RIGHT_SIB_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(rightSibling, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, rightSibling, nodeKey);
+        return;
+      }
+      resizeRightSiblingKey(rightSibling);
+      return;
+    }
     this.rightSiblingKey = rightSibling;
   }
 
+  private void resizeRightSiblingKey(final long value) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.OBJKEY_RIGHT_SIB_KEY, NodeFieldLayout.OBJECT_KEY_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, value, nodeKey));
+  }
+
   @Override
   public long getLeftSiblingKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.OBJKEY_LEFT_SIB_KEY, nodeKey);
+    }
     return leftSiblingKey;
   }
 
   public void setLeftSiblingKey(final long leftSibling) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJKEY_LEFT_SIB_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(leftSibling, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, leftSibling, nodeKey);
+        return;
+      }
+      resizeLeftSiblingKey(leftSibling);
+      return;
+    }
     this.leftSiblingKey = leftSibling;
   }
 
+  private void resizeLeftSiblingKey(final long value) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.OBJKEY_LEFT_SIB_KEY, NodeFieldLayout.OBJECT_KEY_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, value, nodeKey));
+  }
+
   @Override
   public long getFirstChildKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.OBJKEY_FIRST_CHILD_KEY, nodeKey);
+    }
     return firstChildKey;
   }
 
   public void setFirstChildKey(final long firstChild) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJKEY_FIRST_CHILD_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(firstChild, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, firstChild, nodeKey);
+        return;
+      }
+      resizeFirstChildKey(firstChild);
+      return;
+    }
     this.firstChildKey = firstChild;
   }
 
+  private void resizeFirstChildKey(final long value) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.OBJKEY_FIRST_CHILD_KEY, NodeFieldLayout.OBJECT_KEY_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, value, nodeKey));
+  }
+
   @Override
   public long getLastChildKey() {
     // ObjectKeyNode only has one child (the value), so first == last
-    return firstChildKey;
+    return getFirstChildKey();
   }
 
   public void setLastChildKey(final long lastChild) {
@@ -356,6 +822,9 @@ public void decrementChildCount() {
 
   @Override
   public long getDescendantCount() {
+    if (page != null) {
+      return readSignedLongField(NodeFieldLayout.OBJKEY_DESCENDANT_COUNT);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
@@ -364,27 +833,43 @@ public long getDescendantCount() {
 
   @Override
   public void setDescendantCount(final long descendantCount) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJKEY_DESCENDANT_COUNT) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedLongEncodedWidth(descendantCount);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedLongToSegment(page, absOff, descendantCount);
+        return;
+      }
+      resizeDescendantCount(descendantCount);
+      return;
+    }
     this.descendantCount = descendantCount;
   }
 
+  private void resizeDescendantCount(final long value) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.OBJKEY_DESCENDANT_COUNT, NodeFieldLayout.OBJECT_KEY_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedLongToSegment(target, off, value));
+  }
+
   @Override
   public void decrementDescendantCount() {
-    if (!lazyFieldsParsed) {
-      parseLazyFields();
-    }
-    descendantCount--;
+    setDescendantCount(getDescendantCount() - 1);
   }
 
   @Override
   public void incrementDescendantCount() {
-    if (!lazyFieldsParsed) {
-      parseLazyFields();
-    }
-    descendantCount++;
+    setDescendantCount(getDescendantCount() + 1);
   }
 
   @Override
   public int getPreviousRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.OBJKEY_PREV_REVISION);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
@@ -393,6 +878,9 @@ public int getPreviousRevisionNumber() {
 
   @Override
   public int getLastModifiedRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.OBJKEY_LAST_MOD_REVISION);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
@@ -405,22 +893,32 @@ public int getTypeKey() {
 
   @Override
   public boolean hasFirstChild() {
-    return firstChildKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getFirstChildKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public boolean hasLastChild() {
-    return firstChildKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getFirstChildKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public boolean hasLeftSibling() {
-    return leftSiblingKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getLeftSiblingKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public boolean hasRightSibling() {
-    return rightSiblingKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getRightSiblingKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
+  }
+
+  @Override
+  public boolean isWriteSingleton() {
+    return writeSingleton;
+  }
+
+  @Override
+  public void setWriteSingleton(final boolean writeSingleton) {
+    this.writeSingleton = writeSingleton;
   }
 
   @Override
@@ -454,11 +952,13 @@ public void setNodeKey(final long nodeKey) {
   }
 
   /**
-   * Populate this node from a BytesIn source for singleton reuse. LAZY OPTIMIZATION: Only parses
-   * structural fields immediately (NEW ORDER).
+   * Populate this node from a BytesIn source for singleton reuse.
+   * LAZY OPTIMIZATION: Only parses structural fields immediately (NEW ORDER).
    */
   public void readFrom(final BytesIn source, final long nodeKey, final byte[] deweyId,
-      final LongHashFunction hashFunction, final ResourceConfiguration config) {
+                       final LongHashFunction hashFunction, final ResourceConfiguration config) {
+    // Unbind flyweight — ensures getters use Java fields, not stale page reference
+    this.page = null;
     this.nodeKey = nodeKey;
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyId;
@@ -470,13 +970,13 @@ public void readFrom(final BytesIn source, final long nodeKey, final byte[] d
     this.rightSiblingKey = DeltaVarIntCodec.decodeDelta(source, nodeKey);
     this.leftSiblingKey = DeltaVarIntCodec.decodeDelta(source, nodeKey);
     this.firstChildKey = DeltaVarIntCodec.decodeDelta(source, nodeKey);
-
+    
     // Store for lazy parsing
     this.lazySource = source.getSource();
     this.lazyOffset = source.position();
     this.lazyFieldsParsed = false;
     this.hasHash = config.hashType != HashType.NONE;
-
+    
     this.nameKey = 0;
     this.pathNodeKey = 0;
     this.previousRevision = 0;
@@ -484,38 +984,17 @@ public void readFrom(final BytesIn source, final long nodeKey, final byte[] d
     this.hash = 0;
     this.descendantCount = 0;
   }
-
-  public void bindFixedSlotLazy(final MemorySegment slotData, final long baseOffset, final NodeKindLayout layout) {
-    this.lazyBaseOffset = baseOffset;
-    this.lazySource = slotData;
-    this.fixedSlotLayout = layout;
-    this.lazyFieldsParsed = false;
-  }
-
+  
   private void parseLazyFields() {
     if (lazyFieldsParsed) {
       return;
     }
-
-    if (fixedSlotLayout != null) {
-      final MemorySegment sd = (MemorySegment) lazySource;
-      final NodeKindLayout ly = fixedSlotLayout;
-      final long off = this.lazyBaseOffset;
-      this.pathNodeKey = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.PATH_NODE_KEY);
-      this.previousRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.PREVIOUS_REVISION);
-      this.lastModifiedRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.LAST_MODIFIED_REVISION);
-      this.descendantCount = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.DESCENDANT_COUNT);
-      this.hash = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.HASH);
-      this.fixedSlotLayout = null;
-      this.lazyFieldsParsed = true;
-      return;
-    }
-
+    
     if (lazySource == null) {
       lazyFieldsParsed = true;
       return;
     }
-
+    
     BytesIn bytesIn;
     if (lazySource instanceof MemorySegment segment) {
       bytesIn = new MemorySegmentBytesIn(segment);
@@ -526,7 +1005,7 @@ private void parseLazyFields() {
     } else {
       throw new IllegalStateException("Unknown lazy source type: " + lazySource.getClass());
     }
-
+    
     this.nameKey = DeltaVarIntCodec.decodeSigned(bytesIn);
     this.pathNodeKey = DeltaVarIntCodec.decodeDelta(bytesIn, nodeKey);
     this.previousRevision = DeltaVarIntCodec.decodeSigned(bytesIn);
@@ -539,23 +1018,44 @@ private void parseLazyFields() {
   }
 
   /**
-   * Create a deep copy snapshot of this node. Forces parsing of all lazy fields since snapshot must
-   * be independent.
+   * Create a deep copy snapshot of this node.
+   * Forces parsing of all lazy fields since snapshot must be independent.
    */
   public ObjectKeyNode toSnapshot() {
+    if (page != null) {
+      // Bound mode: read all fields from page
+      return new ObjectKeyNode(nodeKey,
+          readDeltaField(NodeFieldLayout.OBJKEY_PARENT_KEY, nodeKey),
+          readDeltaField(NodeFieldLayout.OBJKEY_PATH_NODE_KEY, nodeKey),
+          readSignedField(NodeFieldLayout.OBJKEY_PREV_REVISION),
+          readSignedField(NodeFieldLayout.OBJKEY_LAST_MOD_REVISION),
+          readDeltaField(NodeFieldLayout.OBJKEY_RIGHT_SIB_KEY, nodeKey),
+          readDeltaField(NodeFieldLayout.OBJKEY_LEFT_SIB_KEY, nodeKey),
+          readDeltaField(NodeFieldLayout.OBJKEY_FIRST_CHILD_KEY, nodeKey),
+          readSignedField(NodeFieldLayout.OBJKEY_NAME_KEY),
+          readSignedLongField(NodeFieldLayout.OBJKEY_DESCENDANT_COUNT),
+          readLongField(NodeFieldLayout.OBJKEY_HASH),
+          hashFunction,
+          getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
-    return new ObjectKeyNode(nodeKey, parentKey, pathNodeKey, previousRevision, lastModifiedRevision, rightSiblingKey,
-        leftSiblingKey, firstChildKey, nameKey, descendantCount, hash, hashFunction, deweyIDBytes != null
-            ? deweyIDBytes.clone()
-            : null);
+    return new ObjectKeyNode(nodeKey, parentKey, pathNodeKey, previousRevision, lastModifiedRevision,
+        rightSiblingKey, leftSiblingKey, firstChildKey, nameKey, descendantCount, hash, hashFunction,
+        getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null);
   }
 
   public String toString() {
-    return "ObjectKeyNode{" + "nodeKey=" + nodeKey + ", parentKey=" + parentKey + ", nameKey=" + nameKey
-        + ", pathNodeKey=" + pathNodeKey + ", rightSiblingKey=" + rightSiblingKey + ", leftSiblingKey=" + leftSiblingKey
-        + ", firstChildKey=" + firstChildKey + '}';
+    return "ObjectKeyNode{" +
+        "nodeKey=" + nodeKey +
+        ", parentKey=" + parentKey +
+        ", nameKey=" + nameKey +
+        ", pathNodeKey=" + pathNodeKey +
+        ", rightSiblingKey=" + rightSiblingKey +
+        ", leftSiblingKey=" + leftSiblingKey +
+        ", firstChildKey=" + firstChildKey +
+        '}';
   }
 
   public static Funnel getFunnel() {
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/json/ObjectNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/json/ObjectNode.java
index 9d8e0c91d..5fa13619e 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/json/ObjectNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/json/ObjectNode.java
@@ -43,14 +43,14 @@
 import io.sirix.node.SirixDeweyID;
 
 import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
 import io.sirix.node.immutable.json.ImmutableObjectNode;
-import io.sirix.node.layout.NodeKindLayout;
-import io.sirix.node.layout.SlotLayoutAccessors;
-import io.sirix.node.layout.StructuralField;
+import io.sirix.node.interfaces.FlyweightNode;
 import io.sirix.node.interfaces.Node;
-import io.sirix.node.interfaces.ReusableNodeProxy;
 import io.sirix.node.interfaces.StructNode;
 import io.sirix.node.interfaces.immutable.ImmutableJsonNode;
+import io.sirix.page.KeyValueLeafPage;
+import io.sirix.page.NodeFieldLayout;
 import io.sirix.settings.Fixed;
 import net.openhft.hashing.LongHashFunction;
 import org.checkerframework.checker.nullness.qual.NonNull;
@@ -59,14 +59,12 @@
 /**
  * JSON Object node.
  *
- * 

- * Uses primitive fields for efficient storage with delta+varint encoding. This eliminates
- * MemorySegment/VarHandle overhead and enables compact serialization.
- * 

- * 
+ * 
Uses primitive fields for efficient storage with delta+varint encoding.
+ * This eliminates MemorySegment/VarHandle overhead and enables compact serialization.

+ *
  * @author Johannes Lichtenberger
  */
-public final class ObjectNode implements StructNode, ImmutableJsonNode, ReusableNodeProxy {
+public final class ObjectNode implements StructNode, ImmutableJsonNode, FlyweightNode {
 
   // Node identity (mutable for singleton reuse)
   private long nodeKey;
@@ -98,21 +96,56 @@ public final class ObjectNode implements StructNode, ImmutableJsonNode, Reusable
 
   // Lazy parsing state (single-stage for metadata)
   private Object lazySource;
-  private long lazyBaseOffset;
   private long lazyOffset;
   private boolean lazyFieldsParsed;
   private boolean hasHash;
   private boolean storeChildCount;
 
-  // Fixed-slot lazy support (non-null = use SlotLayoutAccessors for cold fields)
-  private NodeKindLayout fixedSlotLayout;
+  // ==================== FLYWEIGHT BINDING (LeanStore page-direct access) ====================
+
+  /** Page MemorySegment when bound (null = primitive mode). */
+  private MemorySegment page;
+
+  /** Absolute byte offset of this record in the page (after HEAP_START + heapOffset). */
+  private long recordBase;
+
+  /** Absolute byte offset where the data region starts (recordBase + 1 + FIELD_COUNT). */
+  private long dataRegionStart;
+
+  /** Slot index in the page directory (for re-serialization). */
+  private int slotIndex;
+
+  /** True if this node is a factory-managed write singleton (must not be stored in records[]). */
+  private boolean writeSingleton;
+
+  /** Owning page for resize-in-place on varint width changes. */
+  private KeyValueLeafPage ownerPage;
+
+  /** Pre-allocated offset array reused across serializations (zero-alloc hot path). */
+  private final int[] heapOffsets;
+
+  private static final int FIELD_COUNT = NodeFieldLayout.OBJECT_FIELD_COUNT;
 
   /**
-   * Primary constructor with all primitive fields. Used by deserialization
-   * (NodeKind.OBJECT.deserialize).
+   * Constructor for flyweight binding.
+   * All fields except nodeKey and hashFunction will be read from page memory after bind().
+   *
+   * @param nodeKey the node key
+   * @param hashFunction the hash function from resource config
    */
-  public ObjectNode(long nodeKey, long parentKey, int previousRevision, int lastModifiedRevision, long rightSiblingKey,
-      long leftSiblingKey, long firstChildKey, long lastChildKey, long childCount, long descendantCount, long hash,
+  public ObjectNode(long nodeKey, LongHashFunction hashFunction) {
+    this.nodeKey = nodeKey;
+    this.hashFunction = hashFunction;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
+
+  /**
+   * Primary constructor with all primitive fields.
+   * Used by deserialization (NodeKind.OBJECT.deserialize).
+   */
+  public ObjectNode(long nodeKey, long parentKey, int previousRevision,
+      int lastModifiedRevision, long rightSiblingKey, long leftSiblingKey, long firstChildKey,
+      long lastChildKey, long childCount, long descendantCount, long hash,
       LongHashFunction hashFunction, byte[] deweyID) {
     this.nodeKey = nodeKey;
     this.parentKey = parentKey;
@@ -128,14 +161,16 @@ public ObjectNode(long nodeKey, long parentKey, int previousRevision, int lastMo
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyID;
     this.lazyFieldsParsed = true;
+    this.heapOffsets = new int[FIELD_COUNT];
   }
 
   /**
-   * Constructor with SirixDeweyID instead of byte array. Used by factory methods when creating new
-   * nodes.
+   * Constructor with SirixDeweyID instead of byte array.
+   * Used by factory methods when creating new nodes.
    */
-  public ObjectNode(long nodeKey, long parentKey, int previousRevision, int lastModifiedRevision, long rightSiblingKey,
-      long leftSiblingKey, long firstChildKey, long lastChildKey, long childCount, long descendantCount, long hash,
+  public ObjectNode(long nodeKey, long parentKey, int previousRevision,
+      int lastModifiedRevision, long rightSiblingKey, long leftSiblingKey, long firstChildKey,
+      long lastChildKey, long childCount, long descendantCount, long hash,
       LongHashFunction hashFunction, SirixDeweyID deweyID) {
     this.nodeKey = nodeKey;
     this.parentKey = parentKey;
@@ -151,6 +186,227 @@ public ObjectNode(long nodeKey, long parentKey, int previousRevision, int lastMo
     this.hashFunction = hashFunction;
     this.sirixDeweyID = deweyID;
     this.lazyFieldsParsed = true;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
+
+  // ==================== FLYWEIGHT BIND/UNBIND ====================
+
+  /**
+   * Bind this node as a flyweight to a page MemorySegment.
+   * When bound, getters/setters read/write directly to page memory via the offset table.
+   *
+   * @param page       the page MemorySegment
+   * @param recordBase absolute byte offset of this record in the page
+   * @param nodeKey    the node key (for delta decoding)
+   * @param slotIndex  the slot index in the page directory
+   */
+  public void bind(final MemorySegment page, final long recordBase, final long nodeKey,
+      final int slotIndex) {
+    this.page = page;
+    this.recordBase = recordBase;
+    this.nodeKey = nodeKey;
+    this.slotIndex = slotIndex;
+    this.dataRegionStart = recordBase + 1 + FIELD_COUNT;
+    this.lazyFieldsParsed = true; // No lazy state when bound
+    this.lazySource = null;
+  }
+
+  /**
+   * Unbind from page memory and materialize all fields into Java primitives.
+   * After unbind, the node operates in primitive mode.
+   */
+  public void unbind() {
+    if (page == null) {
+      return;
+    }
+    // Materialize all fields from page to Java primitives
+    final long nk = this.nodeKey;
+    this.parentKey = readDeltaField(NodeFieldLayout.OBJECT_PARENT_KEY, nk);
+    this.rightSiblingKey = readDeltaField(NodeFieldLayout.OBJECT_RIGHT_SIB_KEY, nk);
+    this.leftSiblingKey = readDeltaField(NodeFieldLayout.OBJECT_LEFT_SIB_KEY, nk);
+    this.firstChildKey = readDeltaField(NodeFieldLayout.OBJECT_FIRST_CHILD_KEY, nk);
+    this.lastChildKey = readDeltaField(NodeFieldLayout.OBJECT_LAST_CHILD_KEY, nk);
+    this.previousRevision = readSignedField(NodeFieldLayout.OBJECT_PREV_REVISION);
+    this.lastModifiedRevision = readSignedField(NodeFieldLayout.OBJECT_LAST_MOD_REVISION);
+    this.hash = readLongField(NodeFieldLayout.OBJECT_HASH);
+    this.childCount = readSignedLongField(NodeFieldLayout.OBJECT_CHILD_COUNT);
+    this.descendantCount = readSignedLongField(NodeFieldLayout.OBJECT_DESCENDANT_COUNT);
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  @Override
+  public void clearBinding() {
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  /** Check if this node is bound to a page MemorySegment. */
+  public boolean isBound() {
+    return page != null;
+  }
+
+  @Override
+  public boolean isBoundTo(final MemorySegment page) {
+    return this.page == page;
+  }
+
+  @Override
+  public int getSlotIndex() {
+    return slotIndex;
+  }
+
+  // ==================== FLYWEIGHT FIELD READ HELPERS ====================
+
+  private long readDeltaField(final int fieldIndex, final long baseKey) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeDeltaFromSegment(page, dataRegionStart + fieldOff, baseKey);
+  }
+
+  private int readSignedField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeSignedFromSegment(page, dataRegionStart + fieldOff);
+  }
+
+  private long readSignedLongField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeSignedLongFromSegment(page, dataRegionStart + fieldOff);
+  }
+
+  private long readLongField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.readLongFromSegment(page, (int) (dataRegionStart + fieldOff));
+  }
+
+  // ==================== OWNER PAGE (for resize-in-place) ====================
+
+  @Override
+  public KeyValueLeafPage getOwnerPage() {
+    return ownerPage;
+  }
+
+  @Override
+  public void setOwnerPage(final KeyValueLeafPage ownerPage) {
+    this.ownerPage = ownerPage;
+  }
+
+  // ==================== SERIALIZE TO HEAP ====================
+
+  /**
+   * Encode an ObjectNode record directly to a MemorySegment from parameter values.
+   * Static — reads nothing from any instance. Zero field intermediation.
+   *
+   * @param target          the target MemorySegment (reinterpreted slotted page)
+   * @param offset          absolute byte offset to write at
+   * @param heapOffsets     pre-allocated offset array (reused, FIELD_COUNT elements)
+   * @param nodeKey         the node key (delta base for structural keys)
+   * @param parentKey       the parent node key
+   * @param rightSibKey     the right sibling key
+   * @param leftSibKey      the left sibling key
+   * @param firstChildKey   the first child key
+   * @param lastChildKey    the last child key
+   * @param prevRev         the previous revision number
+   * @param lastModRev      the last modified revision number
+   * @param hash            the hash value
+   * @param childCount      the child count
+   * @param descendantCount the descendant count
+   * @return the total number of bytes written
+   */
+  public static int writeNewRecord(final MemorySegment target, final long offset,
+      final int[] heapOffsets, final long nodeKey,
+      final long parentKey, final long rightSibKey, final long leftSibKey,
+      final long firstChildKey, final long lastChildKey,
+      final int prevRev, final int lastModRev, final long hash,
+      final long childCount, final long descendantCount) {
+    long pos = offset;
+
+    // Write nodeKind byte
+    target.set(ValueLayout.JAVA_BYTE, pos, NodeKind.OBJECT.getId());
+    pos++;
+
+    // Reserve space for offset table
+    final long offsetTableStart = pos;
+    pos += FIELD_COUNT;
+
+    // Data region start
+    final long dataStart = pos;
+
+    // Field 0: parentKey (delta-varint)
+    heapOffsets[NodeFieldLayout.OBJECT_PARENT_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, parentKey, nodeKey);
+
+    // Field 1: rightSiblingKey (delta-varint)
+    heapOffsets[NodeFieldLayout.OBJECT_RIGHT_SIB_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, rightSibKey, nodeKey);
+
+    // Field 2: leftSiblingKey (delta-varint)
+    heapOffsets[NodeFieldLayout.OBJECT_LEFT_SIB_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, leftSibKey, nodeKey);
+
+    // Field 3: firstChildKey (delta-varint)
+    heapOffsets[NodeFieldLayout.OBJECT_FIRST_CHILD_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, firstChildKey, nodeKey);
+
+    // Field 4: lastChildKey (delta-varint)
+    heapOffsets[NodeFieldLayout.OBJECT_LAST_CHILD_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, lastChildKey, nodeKey);
+
+    // Field 5: previousRevision (signed varint)
+    heapOffsets[NodeFieldLayout.OBJECT_PREV_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, prevRev);
+
+    // Field 6: lastModifiedRevision (signed varint)
+    heapOffsets[NodeFieldLayout.OBJECT_LAST_MOD_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, lastModRev);
+
+    // Field 7: hash (fixed 8 bytes)
+    heapOffsets[NodeFieldLayout.OBJECT_HASH] = (int) (pos - dataStart);
+    DeltaVarIntCodec.writeLongToSegment(target, pos, hash);
+    pos += Long.BYTES;
+
+    // Field 8: childCount (signed long varint)
+    heapOffsets[NodeFieldLayout.OBJECT_CHILD_COUNT] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedLongToSegment(target, pos, childCount);
+
+    // Field 9: descendantCount (signed long varint)
+    heapOffsets[NodeFieldLayout.OBJECT_DESCENDANT_COUNT] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedLongToSegment(target, pos, descendantCount);
+
+    // Write offset table
+    for (int i = 0; i < FIELD_COUNT; i++) {
+      target.set(ValueLayout.JAVA_BYTE, offsetTableStart + i, (byte) heapOffsets[i]);
+    }
+
+    return (int) (pos - offset);
+  }
+
+  /**
+   * Serialize this node from Java fields. Delegates to static writeNewRecord.
+   */
+  public int serializeToHeap(final MemorySegment target, final long offset) {
+    if (!lazyFieldsParsed) {
+      parseLazyFields();
+    }
+    return writeNewRecord(target, offset, heapOffsets, nodeKey,
+        parentKey, rightSiblingKey, leftSiblingKey,
+        firstChildKey, lastChildKey, previousRevision, lastModifiedRevision,
+        hash, childCount, descendantCount);
+  }
+
+  /**
+   * Get the pre-allocated heap offsets array for use with static writeNewRecord.
+   */
+  public int[] getHeapOffsets() {
+    return heapOffsets;
+  }
+
+  /**
+   * Set DeweyID fields directly after creation, bypassing write-through.
+   * The DeweyID is already in the page trailer — this just sets the Java cache fields.
+   */
+  public void setDeweyIDAfterCreation(final SirixDeweyID id, final byte[] bytes) {
+    this.sirixDeweyID = id;
+    this.deweyIDBytes = bytes;
   }
 
   @Override
@@ -165,16 +421,38 @@ public long getNodeKey() {
 
   @Override
   public long getParentKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.OBJECT_PARENT_KEY, nodeKey);
+    }
     return parentKey;
   }
 
   public void setParentKey(final long parentKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJECT_PARENT_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(parentKey, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, parentKey, nodeKey);
+        return;
+      }
+      resizeParentKey(parentKey);
+      return;
+    }
     this.parentKey = parentKey;
   }
 
+  private void resizeParentKey(final long parentKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.OBJECT_PARENT_KEY, NodeFieldLayout.OBJECT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, parentKey, nodeKey));
+  }
+
   @Override
   public boolean hasParent() {
-    return parentKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getParentKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
@@ -189,27 +467,79 @@ public void setTypeKey(final int typeKey) {
 
   @Override
   public void setDeweyID(final SirixDeweyID id) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.sirixDeweyID = id;
+      this.deweyIDBytes = null;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
     this.sirixDeweyID = id;
-    this.deweyIDBytes = null; // Clear cached bytes
+    this.deweyIDBytes = null;
   }
 
-  public void setDeweyIDBytes(final byte[] deweyIDBytes) {
-    this.deweyIDBytes = deweyIDBytes;
+  @Override
+  public void setDeweyIDBytes(final byte[] bytes) {
+    this.deweyIDBytes = bytes;
     this.sirixDeweyID = null;
   }
 
   @Override
   public void setPreviousRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJECT_PREV_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizePreviousRevision(revision);
+      return;
+    }
     this.previousRevision = revision;
   }
 
+  private void resizePreviousRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.OBJECT_PREV_REVISION, NodeFieldLayout.OBJECT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+  }
+
   @Override
   public void setLastModifiedRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJECT_LAST_MOD_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizeLastModifiedRevision(revision);
+      return;
+    }
     this.lastModifiedRevision = revision;
   }
 
+  private void resizeLastModifiedRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.OBJECT_LAST_MOD_REVISION, NodeFieldLayout.OBJECT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+  }
+
   @Override
   public long getHash() {
+    if (page != null) {
+      return readLongField(NodeFieldLayout.OBJECT_HASH);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
@@ -218,13 +548,22 @@ public long getHash() {
 
   @Override
   public void setHash(final long hash) {
+    if (page != null) {
+      // Hash is ALWAYS in-place (fixed 8 bytes)
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJECT_HASH) & 0xFF;
+      DeltaVarIntCodec.writeLongToSegment(page, dataRegionStart + fieldOff, hash);
+      return;
+    }
     this.hash = hash;
   }
 
   @Override
   public long computeHash(final BytesOut bytes) {
     bytes.clear();
-    bytes.writeLong(getNodeKey()).writeLong(getParentKey()).writeByte(getKind().getId());
+    bytes.writeLong(getNodeKey())
+         .writeLong(getParentKey())
+         .writeByte(getKind().getId());
 
     bytes.writeLong(getChildCount())
          .writeLong(getDescendantCount())
@@ -241,45 +580,133 @@ public long computeHash(final BytesOut bytes) {
 
   @Override
   public long getRightSiblingKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.OBJECT_RIGHT_SIB_KEY, nodeKey);
+    }
     return rightSiblingKey;
   }
 
   public void setRightSiblingKey(final long rightSibling) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJECT_RIGHT_SIB_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(rightSibling, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, rightSibling, nodeKey);
+        return;
+      }
+      resizeRightSiblingKey(rightSibling);
+      return;
+    }
     this.rightSiblingKey = rightSibling;
   }
 
+  private void resizeRightSiblingKey(final long rightSibling) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.OBJECT_RIGHT_SIB_KEY, NodeFieldLayout.OBJECT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, rightSibling, nodeKey));
+  }
+
   @Override
   public long getLeftSiblingKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.OBJECT_LEFT_SIB_KEY, nodeKey);
+    }
     return leftSiblingKey;
   }
 
   public void setLeftSiblingKey(final long leftSibling) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJECT_LEFT_SIB_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(leftSibling, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, leftSibling, nodeKey);
+        return;
+      }
+      resizeLeftSiblingKey(leftSibling);
+      return;
+    }
     this.leftSiblingKey = leftSibling;
   }
 
+  private void resizeLeftSiblingKey(final long leftSibling) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.OBJECT_LEFT_SIB_KEY, NodeFieldLayout.OBJECT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, leftSibling, nodeKey));
+  }
+
   @Override
   public long getFirstChildKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.OBJECT_FIRST_CHILD_KEY, nodeKey);
+    }
     return firstChildKey;
   }
 
   public void setFirstChildKey(final long firstChild) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJECT_FIRST_CHILD_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(firstChild, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, firstChild, nodeKey);
+        return;
+      }
+      resizeFirstChildKey(firstChild);
+      return;
+    }
     this.firstChildKey = firstChild;
   }
 
+  private void resizeFirstChildKey(final long firstChild) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.OBJECT_FIRST_CHILD_KEY, NodeFieldLayout.OBJECT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, firstChild, nodeKey));
+  }
+
   @Override
   public long getLastChildKey() {
-    if (!lazyFieldsParsed) {
-      parseLazyFields();
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.OBJECT_LAST_CHILD_KEY, nodeKey);
     }
     return lastChildKey;
   }
 
   public void setLastChildKey(final long lastChild) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJECT_LAST_CHILD_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(lastChild, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, lastChild, nodeKey);
+        return;
+      }
+      resizeLastChildKey(lastChild);
+      return;
+    }
     this.lastChildKey = lastChild;
   }
 
+  private void resizeLastChildKey(final long lastChild) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.OBJECT_LAST_CHILD_KEY, NodeFieldLayout.OBJECT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, lastChild, nodeKey));
+  }
+
   @Override
   public long getChildCount() {
+    if (page != null) {
+      return readSignedLongField(NodeFieldLayout.OBJECT_CHILD_COUNT);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
@@ -287,11 +714,33 @@ public long getChildCount() {
   }
 
   public void setChildCount(final long childCount) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJECT_CHILD_COUNT) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedLongEncodedWidth(childCount);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedLongToSegment(page, absOff, childCount);
+        return;
+      }
+      resizeChildCount(childCount);
+      return;
+    }
     this.childCount = childCount;
   }
 
+  private void resizeChildCount(final long childCount) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.OBJECT_CHILD_COUNT, NodeFieldLayout.OBJECT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedLongToSegment(target, off, childCount));
+  }
+
   @Override
   public long getDescendantCount() {
+    if (page != null) {
+      return readSignedLongField(NodeFieldLayout.OBJECT_DESCENDANT_COUNT);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
@@ -299,66 +748,73 @@ public long getDescendantCount() {
   }
 
   public void setDescendantCount(final long descendantCount) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJECT_DESCENDANT_COUNT) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedLongEncodedWidth(descendantCount);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedLongToSegment(page, absOff, descendantCount);
+        return;
+      }
+      resizeDescendantCount(descendantCount);
+      return;
+    }
     this.descendantCount = descendantCount;
   }
 
+  private void resizeDescendantCount(final long descendantCount) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.OBJECT_DESCENDANT_COUNT, NodeFieldLayout.OBJECT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedLongToSegment(target, off, descendantCount));
+  }
+
   @Override
   public boolean hasFirstChild() {
-    return firstChildKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getFirstChildKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public boolean hasLastChild() {
-    if (!lazyFieldsParsed) {
-      parseLazyFields();
-    }
-    return lastChildKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getLastChildKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public void incrementChildCount() {
-    if (!lazyFieldsParsed) {
-      parseLazyFields();
-    }
-    childCount++;
+    setChildCount(getChildCount() + 1);
   }
 
   @Override
   public void decrementChildCount() {
-    if (!lazyFieldsParsed) {
-      parseLazyFields();
-    }
-    childCount--;
+    setChildCount(getChildCount() - 1);
   }
 
   @Override
   public void incrementDescendantCount() {
-    if (!lazyFieldsParsed) {
-      parseLazyFields();
-    }
-    descendantCount++;
+    setDescendantCount(getDescendantCount() + 1);
   }
 
   @Override
   public void decrementDescendantCount() {
-    if (!lazyFieldsParsed) {
-      parseLazyFields();
-    }
-    descendantCount--;
+    setDescendantCount(getDescendantCount() - 1);
   }
 
   @Override
   public boolean hasLeftSibling() {
-    return leftSiblingKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getLeftSiblingKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public boolean hasRightSibling() {
-    return rightSiblingKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getRightSiblingKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public int getPreviousRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.OBJECT_PREV_REVISION);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
@@ -367,6 +823,9 @@ public int getPreviousRevisionNumber() {
 
   @Override
   public int getLastModifiedRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.OBJECT_LAST_MOD_REVISION);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
@@ -383,11 +842,13 @@ public void setNodeKey(final long nodeKey) {
   }
 
   /**
-   * Populate this node from a BytesIn source for singleton reuse. LAZY OPTIMIZATION: Only parses
-   * structural fields immediately (NEW ORDER).
+   * Populate this node from a BytesIn source for singleton reuse.
+   * LAZY OPTIMIZATION: Only parses structural fields immediately (NEW ORDER).
    */
   public void readFrom(final BytesIn source, final long nodeKey, final byte[] deweyId,
-      final LongHashFunction hashFunction, final ResourceConfiguration config) {
+                       final LongHashFunction hashFunction, final ResourceConfiguration config) {
+    // Unbind flyweight — ensures getters use Java fields, not stale page reference
+    this.page = null;
     this.nodeKey = nodeKey;
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyId;
@@ -415,19 +876,20 @@ public void readFrom(final BytesIn source, final long nodeKey, final byte[] d
   }
 
   /**
-   * Populate this node directly from a MemorySegment, bypassing BytesIn overhead. ZERO ALLOCATION -
-   * reads directly from memory segment.
-   * 
-   * @param segment the MemorySegment containing the serialized node data (after kind byte)
+   * Populate this node directly from a MemorySegment, bypassing BytesIn overhead.
+   * ZERO ALLOCATION - reads directly from memory segment.
+   *
+   * @param segment     the MemorySegment containing the serialized node data (after kind byte)
    * @param startOffset the byte offset within the segment to start reading
-   * @param nodeKey the node key
-   * @param deweyId the DeweyID bytes (may be null)
+   * @param nodeKey     the node key
+   * @param deweyId     the DeweyID bytes (may be null)
    * @param hashFunction the hash function
-   * @param config the resource configuration
+   * @param config      the resource configuration
    * @return the byte offset after reading all structural fields (for lazy field position)
    */
   public int readFromSegment(final MemorySegment segment, final int startOffset, final long nodeKey,
-      final byte[] deweyId, final LongHashFunction hashFunction, final ResourceConfiguration config) {
+                              final byte[] deweyId, final LongHashFunction hashFunction,
+                              final ResourceConfiguration config) {
     this.nodeKey = nodeKey;
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyId;
@@ -467,38 +929,11 @@ public int readFromSegment(final MemorySegment segment, final int startOffset, f
     return offset;
   }
 
-  /**
-   * Bind this singleton for fixed-slot lazy cold-field reading. Hot fields (parentKey, siblings,
-   * firstChildKey) must already be set. Cold fields (hash, childCount, descendantCount, lastChildKey,
-   * prevRev, lastModRev) will be read on demand via parseLazyFields().
-   */
-  public void bindFixedSlotLazy(final MemorySegment slotData, final long baseOffset, final NodeKindLayout layout) {
-    this.lazyBaseOffset = baseOffset;
-    this.lazySource = slotData;
-    this.fixedSlotLayout = layout;
-    this.lazyFieldsParsed = false;
-  }
-
   private void parseLazyFields() {
     if (lazyFieldsParsed) {
       return;
     }
 
-    if (fixedSlotLayout != null) {
-      final MemorySegment sd = (MemorySegment) lazySource;
-      final NodeKindLayout ly = fixedSlotLayout;
-      final long off = this.lazyBaseOffset;
-      this.previousRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.PREVIOUS_REVISION);
-      this.lastModifiedRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.LAST_MODIFIED_REVISION);
-      this.lastChildKey = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.LAST_CHILD_KEY);
-      this.childCount = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.CHILD_COUNT);
-      this.descendantCount = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.DESCENDANT_COUNT);
-      this.hash = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.HASH);
-      this.fixedSlotLayout = null;
-      this.lazyFieldsParsed = true;
-      return;
-    }
-
     if (lazySource == null) {
       lazyFieldsParsed = true;
       return;
@@ -517,9 +952,7 @@ private void parseLazyFields() {
 
     this.previousRevision = DeltaVarIntCodec.decodeSigned(bytesIn);
     this.lastModifiedRevision = DeltaVarIntCodec.decodeSigned(bytesIn);
-    this.childCount = storeChildCount
-        ? DeltaVarIntCodec.decodeSigned(bytesIn)
-        : 0;
+    this.childCount = storeChildCount ? DeltaVarIntCodec.decodeSigned(bytesIn) : 0;
     if (hasHash) {
       this.hash = bytesIn.readLong();
       this.descendantCount = DeltaVarIntCodec.decodeSigned(bytesIn);
@@ -528,17 +961,50 @@ private void parseLazyFields() {
   }
 
   /**
-   * Create a deep copy snapshot of this node. Forces parsing of all lazy fields since snapshot must
-   * be independent.
+   * Create a deep copy snapshot of this node.
+   * Forces parsing of all lazy fields since snapshot must be independent.
    */
   public ObjectNode toSnapshot() {
+    if (page != null) {
+      // Bound mode: read all fields from page
+      return new ObjectNode(nodeKey,
+          readDeltaField(NodeFieldLayout.OBJECT_PARENT_KEY, nodeKey),
+          readSignedField(NodeFieldLayout.OBJECT_PREV_REVISION),
+          readSignedField(NodeFieldLayout.OBJECT_LAST_MOD_REVISION),
+          readDeltaField(NodeFieldLayout.OBJECT_RIGHT_SIB_KEY, nodeKey),
+          readDeltaField(NodeFieldLayout.OBJECT_LEFT_SIB_KEY, nodeKey),
+          readDeltaField(NodeFieldLayout.OBJECT_FIRST_CHILD_KEY, nodeKey),
+          readDeltaField(NodeFieldLayout.OBJECT_LAST_CHILD_KEY, nodeKey),
+          readSignedLongField(NodeFieldLayout.OBJECT_CHILD_COUNT),
+          readSignedLongField(NodeFieldLayout.OBJECT_DESCENDANT_COUNT),
+          readLongField(NodeFieldLayout.OBJECT_HASH),
+          hashFunction,
+          getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
-    return new ObjectNode(nodeKey, parentKey, previousRevision, lastModifiedRevision, rightSiblingKey, leftSiblingKey,
-        firstChildKey, lastChildKey, childCount, descendantCount, hash, hashFunction, deweyIDBytes != null
-            ? deweyIDBytes.clone()
-            : null);
+    return new ObjectNode(nodeKey, parentKey, previousRevision, lastModifiedRevision,
+        rightSiblingKey, leftSiblingKey, firstChildKey, lastChildKey, childCount,
+        descendantCount, hash, hashFunction,
+        getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null);
+  }
+
+  @Override
+  public int estimateSerializedSize() {
+    // 1 (nodeKind) + 10 (offset table) + ~20 (varint fields avg) + 8 (hash) = ~39
+    // Use conservative upper bound
+    return 1 + FIELD_COUNT + 10 * 2 + 8 + 2 * 2;
+  }
+
+  @Override
+  public boolean isWriteSingleton() {
+    return writeSingleton;
+  }
+
+  @Override
+  public void setWriteSingleton(final boolean writeSingleton) {
+    this.writeSingleton = writeSingleton;
   }
 
   @Override
@@ -589,6 +1055,7 @@ public boolean equals(final Object obj) {
     if (!(obj instanceof final ObjectNode other))
       return false;
 
-    return nodeKey == other.nodeKey && parentKey == other.parentKey;
+    return nodeKey == other.nodeKey
+        && parentKey == other.parentKey;
   }
 }
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/json/ObjectNullNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/json/ObjectNullNode.java
index ef1391451..7684db2bd 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/json/ObjectNullNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/json/ObjectNullNode.java
@@ -31,9 +31,9 @@
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Objects;
 import io.sirix.access.ResourceConfiguration;
-import io.sirix.access.trx.node.HashType;
 import io.sirix.api.visitor.JsonNodeVisitor;
 import io.sirix.api.visitor.VisitResult;
+import io.sirix.node.Bytes;
 import io.sirix.node.ByteArrayBytesIn;
 import io.sirix.node.BytesIn;
 import io.sirix.node.BytesOut;
@@ -41,31 +41,29 @@
 import io.sirix.node.MemorySegmentBytesIn;
 import io.sirix.node.NodeKind;
 import io.sirix.node.SirixDeweyID;
-
-import java.lang.foreign.MemorySegment;
 import io.sirix.node.immutable.json.ImmutableObjectNullNode;
-import io.sirix.node.layout.NodeKindLayout;
-import io.sirix.node.layout.SlotLayoutAccessors;
-import io.sirix.node.layout.StructuralField;
+import io.sirix.node.interfaces.FlyweightNode;
 import io.sirix.node.interfaces.Node;
-import io.sirix.node.interfaces.ReusableNodeProxy;
 import io.sirix.node.interfaces.StructNode;
 import io.sirix.node.interfaces.immutable.ImmutableJsonNode;
+import io.sirix.page.KeyValueLeafPage;
+import io.sirix.page.NodeFieldLayout;
 import io.sirix.settings.Fixed;
 import net.openhft.hashing.LongHashFunction;
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
+import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
+
 /**
  * JSON Object Null node (direct child of ObjectKeyNode, no siblings).
  *
- * 

- * Uses primitive fields for efficient storage with delta+varint encoding.
- * 

- * 
+ * 
Uses primitive fields for efficient storage with delta+varint encoding.

+ *
  * @author Johannes Lichtenberger
  */
-public final class ObjectNullNode implements StructNode, ImmutableJsonNode, ReusableNodeProxy {
+public final class ObjectNullNode implements StructNode, ImmutableJsonNode, FlyweightNode {
 
   // Node identity (mutable for singleton reuse)
   private long nodeKey;
@@ -89,18 +87,53 @@ public final class ObjectNullNode implements StructNode, ImmutableJsonNode, Reus
 
   // Lazy parsing state (single-stage since there's no value to parse)
   private Object lazySource;
-  private long lazyBaseOffset;
   private long lazyOffset;
   private boolean lazyFieldsParsed;
-  private boolean hasHash;
 
-  // Fixed-slot lazy support
-  private NodeKindLayout fixedSlotLayout;
+
+  // ==================== FLYWEIGHT BINDING (LeanStore page-direct access) ====================
+
+  /** Page MemorySegment when bound (null = primitive mode). */
+  private MemorySegment page;
+
+  /** Absolute byte offset of this record in the page (after HEAP_START + heapOffset). */
+  private long recordBase;
+
+  /** Absolute byte offset where the data region starts (recordBase + 1 + FIELD_COUNT). */
+  private long dataRegionStart;
+
+  /** Slot index in the page directory (for re-serialization). */
+  private int slotIndex;
+
+  /** True if this node is a factory-managed write singleton (must not be stored in records[]). */
+  private boolean writeSingleton;
+
+  /** Owning page for resize-in-place on varint width changes. */
+  private KeyValueLeafPage ownerPage;
+
+  /** Pre-allocated offset array reused across serializations (zero-alloc hot path). */
+  private final int[] heapOffsets;
+
+  private static final int FIELD_COUNT = NodeFieldLayout.OBJECT_NULL_VALUE_FIELD_COUNT;
+
+  /**
+   * Constructor for flyweight binding.
+   * All fields except nodeKey and hashFunction will be read from page memory after bind().
+   *
+   * @param nodeKey the node key
+   * @param hashFunction the hash function from resource config
+   */
+  public ObjectNullNode(long nodeKey, LongHashFunction hashFunction) {
+    this.nodeKey = nodeKey;
+    this.hashFunction = hashFunction;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
 
   /**
    * Primary constructor with all primitive fields.
    */
-  public ObjectNullNode(long nodeKey, long parentKey, int previousRevision, int lastModifiedRevision, long hash,
+  public ObjectNullNode(long nodeKey, long parentKey, int previousRevision,
+      int lastModifiedRevision, long hash,
       LongHashFunction hashFunction, byte[] deweyID) {
     this.nodeKey = nodeKey;
     this.parentKey = parentKey;
@@ -110,12 +143,14 @@ public ObjectNullNode(long nodeKey, long parentKey, int previousRevision, int la
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyID;
     this.lazyFieldsParsed = true;
+    this.heapOffsets = new int[FIELD_COUNT];
   }
 
   /**
    * Constructor with SirixDeweyID instead of byte array.
    */
-  public ObjectNullNode(long nodeKey, long parentKey, int previousRevision, int lastModifiedRevision, long hash,
+  public ObjectNullNode(long nodeKey, long parentKey, int previousRevision,
+      int lastModifiedRevision, long hash,
       LongHashFunction hashFunction, SirixDeweyID deweyID) {
     this.nodeKey = nodeKey;
     this.parentKey = parentKey;
@@ -125,6 +160,182 @@ public ObjectNullNode(long nodeKey, long parentKey, int previousRevision, int la
     this.hashFunction = hashFunction;
     this.sirixDeweyID = deweyID;
     this.lazyFieldsParsed = true;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
+
+  // ==================== FLYWEIGHT BIND/UNBIND ====================
+
+  /**
+   * Bind this node as a flyweight to a page MemorySegment.
+   * When bound, getters/setters read/write directly to page memory via the offset table.
+   *
+   * @param page       the page MemorySegment
+   * @param recordBase absolute byte offset of this record in the page
+   * @param nodeKey    the node key (for delta decoding)
+   * @param slotIndex  the slot index in the page directory
+   */
+  public void bind(final MemorySegment page, final long recordBase, final long nodeKey,
+      final int slotIndex) {
+    this.page = page;
+    this.recordBase = recordBase;
+    this.nodeKey = nodeKey;
+    this.slotIndex = slotIndex;
+    this.dataRegionStart = recordBase + 1 + FIELD_COUNT;
+    this.hash = 0;
+    this.lazyFieldsParsed = true; // No lazy state when bound
+    this.lazySource = null;
+  }
+
+  /**
+   * Unbind from page memory and materialize all fields into Java primitives.
+   * After unbind, the node operates in primitive mode.
+   */
+  public void unbind() {
+    if (page == null) {
+      return;
+    }
+    // Materialize all fields from page to Java primitives
+    final long nk = this.nodeKey;
+    this.parentKey = readDeltaField(NodeFieldLayout.OBJNULLVAL_PARENT_KEY, nk);
+    this.previousRevision = readSignedField(NodeFieldLayout.OBJNULLVAL_PREV_REVISION);
+    this.lastModifiedRevision = readSignedField(NodeFieldLayout.OBJNULLVAL_LAST_MOD_REVISION);
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  @Override
+  public void clearBinding() {
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  /** Check if this node is bound to a page MemorySegment. */
+  public boolean isBound() {
+    return page != null;
+  }
+
+  @Override
+  public boolean isBoundTo(final MemorySegment page) {
+    return this.page == page;
+  }
+
+  @Override
+  public int getSlotIndex() {
+    return slotIndex;
+  }
+
+  // ==================== FLYWEIGHT FIELD READ HELPERS ====================
+
+  private long readDeltaField(final int fieldIndex, final long baseKey) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeDeltaFromSegment(page, dataRegionStart + fieldOff, baseKey);
+  }
+
+  private int readSignedField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeSignedFromSegment(page, dataRegionStart + fieldOff);
+  }
+
+  /**
+   * Resize a single field via raw-copy on the owning slotted page.
+   * Avoids the full unbind-to-primitives + re-serialize round-trip.
+   *
+   * @param fieldIndex the field index in the offset table (e.g. {@code OBJNULLVAL_PARENT_KEY})
+   * @param encoder    writes the new field value at the target offset
+   */
+  private void resizeRecordField(final int fieldIndex,
+      final DeltaVarIntCodec.FieldEncoder encoder) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex, fieldIndex, FIELD_COUNT, encoder);
+  }
+
+  // ==================== OWNER PAGE (for resize-in-place) ====================
+
+  @Override
+  public KeyValueLeafPage getOwnerPage() {
+    return ownerPage;
+  }
+
+  @Override
+  public void setOwnerPage(final KeyValueLeafPage ownerPage) {
+    this.ownerPage = ownerPage;
+  }
+
+  // ==================== SERIALIZE TO HEAP ====================
+
+  /**
+   * Encode an ObjectNullNode record directly to a MemorySegment from parameter values.
+   * Static -- reads nothing from any instance. Zero field intermediation.
+   *
+   * @param target      the target MemorySegment (reinterpreted slotted page)
+   * @param offset      absolute byte offset to write at
+   * @param heapOffsets pre-allocated offset array (reused, FIELD_COUNT elements)
+   * @param nodeKey     the node key (delta base for structural keys)
+   * @param parentKey   the parent node key
+   * @param prevRev     the previous revision number
+   * @param lastModRev  the last modified revision number
+   * @return the total number of bytes written
+   */
+  public static int writeNewRecord(final MemorySegment target, final long offset,
+      final int[] heapOffsets, final long nodeKey,
+      final long parentKey, final int prevRev, final int lastModRev) {
+    long pos = offset;
+
+    // Write nodeKind byte
+    target.set(ValueLayout.JAVA_BYTE, pos, NodeKind.OBJECT_NULL_VALUE.getId());
+    pos++;
+
+    // Reserve space for offset table
+    final long offsetTableStart = pos;
+    pos += FIELD_COUNT;
+
+    // Data region start
+    final long dataStart = pos;
+
+    // Field 0: parentKey (delta-varint)
+    heapOffsets[NodeFieldLayout.OBJNULLVAL_PARENT_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, parentKey, nodeKey);
+
+    // Field 1: previousRevision (signed varint)
+    heapOffsets[NodeFieldLayout.OBJNULLVAL_PREV_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, prevRev);
+
+    // Field 2: lastModifiedRevision (signed varint)
+    heapOffsets[NodeFieldLayout.OBJNULLVAL_LAST_MOD_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, lastModRev);
+
+    // Write offset table
+    for (int i = 0; i < FIELD_COUNT; i++) {
+      target.set(ValueLayout.JAVA_BYTE, offsetTableStart + i, (byte) heapOffsets[i]);
+    }
+
+    return (int) (pos - offset);
+  }
+
+  /**
+   * Serialize this node from Java fields. Delegates to static writeNewRecord.
+   */
+  public int serializeToHeap(final MemorySegment target, final long offset) {
+    if (!lazyFieldsParsed) {
+      parseLazyFields();
+    }
+    return writeNewRecord(target, offset, heapOffsets, nodeKey,
+        parentKey, previousRevision, lastModifiedRevision);
+  }
+
+  /**
+   * Get the pre-allocated heap offsets array for use with static writeNewRecord.
+   */
+  public int[] getHeapOffsets() {
+    return heapOffsets;
+  }
+
+  /**
+   * Set DeweyID fields directly after creation, bypassing write-through.
+   * The DeweyID is already in the page trailer -- this just sets the Java cache fields.
+   */
+  public void setDeweyIDAfterCreation(final SirixDeweyID id, final byte[] bytes) {
+    this.sirixDeweyID = id;
+    this.deweyIDBytes = bytes;
   }
 
   @Override
@@ -139,16 +350,33 @@ public long getNodeKey() {
 
   @Override
   public long getParentKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.OBJNULLVAL_PARENT_KEY, nodeKey);
+    }
     return parentKey;
   }
 
   public void setParentKey(final long parentKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJNULLVAL_PARENT_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(parentKey, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, parentKey, nodeKey);
+        return;
+      }
+      resizeRecordField(NodeFieldLayout.OBJNULLVAL_PARENT_KEY,
+          (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, parentKey, nodeKey));
+      return;
+    }
     this.parentKey = parentKey;
   }
 
   @Override
   public boolean hasParent() {
-    return parentKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getParentKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
@@ -161,31 +389,73 @@ public void setTypeKey(final int typeKey) {}
 
   @Override
   public void setDeweyID(final SirixDeweyID id) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.sirixDeweyID = id;
+      this.deweyIDBytes = null;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
     this.sirixDeweyID = id;
     this.deweyIDBytes = null;
   }
 
-  public void setDeweyIDBytes(final byte[] deweyIDBytes) {
-    this.deweyIDBytes = deweyIDBytes;
+  @Override
+  public void setDeweyIDBytes(final byte[] bytes) {
+    this.deweyIDBytes = bytes;
     this.sirixDeweyID = null;
   }
 
   @Override
   public void setPreviousRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJNULLVAL_PREV_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizeRecordField(NodeFieldLayout.OBJNULLVAL_PREV_REVISION,
+          (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+      return;
+    }
     this.previousRevision = revision;
   }
 
   @Override
   public void setLastModifiedRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJNULLVAL_LAST_MOD_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizeRecordField(NodeFieldLayout.OBJNULLVAL_LAST_MOD_REVISION,
+          (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+      return;
+    }
     this.lastModifiedRevision = revision;
   }
 
   @Override
   public long getHash() {
-    if (!lazyFieldsParsed) {
-      parseLazyFields();
+    if (hash != 0L) {
+      return hash;
     }
-    return hash;
+    if (hashFunction != null) {
+      return computeHash(Bytes.threadLocalHashBuffer());
+    }
+    return 0L;
   }
 
   @Override
@@ -196,7 +466,9 @@ public void setHash(final long hash) {
   @Override
   public long computeHash(final BytesOut bytes) {
     bytes.clear();
-    bytes.writeLong(getNodeKey()).writeLong(getParentKey()).writeByte(getKind().getId());
+    bytes.writeLong(getNodeKey())
+         .writeLong(getParentKey())
+         .writeByte(getKind().getId());
     return bytes.hashDirect(hashFunction);
   }
 
@@ -276,6 +548,9 @@ public boolean hasRightSibling() {
 
   @Override
   public int getPreviousRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.OBJNULLVAL_PREV_REVISION);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
@@ -284,6 +559,9 @@ public int getPreviousRevisionNumber() {
 
   @Override
   public int getLastModifiedRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.OBJNULLVAL_LAST_MOD_REVISION);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
@@ -300,7 +578,9 @@ public void setNodeKey(final long nodeKey) {
   }
 
   public void readFrom(final BytesIn source, final long nodeKey, final byte[] deweyId,
-      final LongHashFunction hashFunction, final ResourceConfiguration config) {
+                       final LongHashFunction hashFunction, final ResourceConfiguration config) {
+    // Unbind flyweight — ensures getters use Java fields, not stale page reference
+    this.page = null;
     this.nodeKey = nodeKey;
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyId;
@@ -313,37 +593,17 @@ public void readFrom(final BytesIn source, final long nodeKey, final byte[] d
     this.lazySource = source.getSource();
     this.lazyOffset = source.position();
     this.lazyFieldsParsed = false;
-    this.hasHash = config.hashType != HashType.NONE;
 
     this.previousRevision = 0;
     this.lastModifiedRevision = 0;
     this.hash = 0;
   }
 
-  public void bindFixedSlotLazy(final MemorySegment slotData, final long baseOffset, final NodeKindLayout layout) {
-    this.lazyBaseOffset = baseOffset;
-    this.lazySource = slotData;
-    this.fixedSlotLayout = layout;
-    this.lazyFieldsParsed = false;
-  }
-
   private void parseLazyFields() {
     if (lazyFieldsParsed) {
       return;
     }
 
-    if (fixedSlotLayout != null) {
-      final MemorySegment sd = (MemorySegment) lazySource;
-      final NodeKindLayout ly = fixedSlotLayout;
-      final long off = this.lazyBaseOffset;
-      this.previousRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.PREVIOUS_REVISION);
-      this.lastModifiedRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.LAST_MODIFIED_REVISION);
-      this.hash = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.HASH);
-      this.fixedSlotLayout = null;
-      this.lazyFieldsParsed = true;
-      return;
-    }
-
     if (lazySource == null) {
       lazyFieldsParsed = true;
       return;
@@ -362,20 +622,36 @@ private void parseLazyFields() {
 
     this.previousRevision = DeltaVarIntCodec.decodeSigned(bytesIn);
     this.lastModifiedRevision = DeltaVarIntCodec.decodeSigned(bytesIn);
-    if (hasHash) {
-      this.hash = bytesIn.readLong();
-    }
     this.lazyFieldsParsed = true;
   }
 
   public ObjectNullNode toSnapshot() {
+    if (page != null) {
+      // Bound mode: read all fields from page
+      return new ObjectNullNode(nodeKey,
+          readDeltaField(NodeFieldLayout.OBJNULLVAL_PARENT_KEY, nodeKey),
+          readSignedField(NodeFieldLayout.OBJNULLVAL_PREV_REVISION),
+          readSignedField(NodeFieldLayout.OBJNULLVAL_LAST_MOD_REVISION),
+          hash,
+          hashFunction,
+          getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null);
+    }
     if (!lazyFieldsParsed) {
       parseLazyFields();
     }
-    return new ObjectNullNode(nodeKey, parentKey, previousRevision, lastModifiedRevision, hash, hashFunction,
-        deweyIDBytes != null
-            ? deweyIDBytes.clone()
-            : null);
+    return new ObjectNullNode(nodeKey, parentKey, previousRevision, lastModifiedRevision,
+        hash, hashFunction,
+        getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null);
+  }
+
+  @Override
+  public boolean isWriteSingleton() {
+    return writeSingleton;
+  }
+
+  @Override
+  public void setWriteSingleton(final boolean writeSingleton) {
+    this.writeSingleton = writeSingleton;
   }
 
   @Override
@@ -419,6 +695,7 @@ public boolean equals(final Object obj) {
     if (!(obj instanceof final ObjectNullNode other))
       return false;
 
-    return nodeKey == other.nodeKey && parentKey == other.parentKey;
+    return nodeKey == other.nodeKey
+        && parentKey == other.parentKey;
   }
 }
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/json/ObjectNumberNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/json/ObjectNumberNode.java
index 3bd0a0497..337a9dde5 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/json/ObjectNumberNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/json/ObjectNumberNode.java
@@ -31,27 +31,29 @@
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Objects;
 import io.sirix.access.ResourceConfiguration;
-import io.sirix.access.trx.node.HashType;
 import io.sirix.api.visitor.JsonNodeVisitor;
 import io.sirix.api.visitor.VisitResult;
+import io.sirix.node.Bytes;
 import io.sirix.node.ByteArrayBytesIn;
 import io.sirix.node.BytesIn;
 import io.sirix.node.BytesOut;
 import io.sirix.node.DeltaVarIntCodec;
 import io.sirix.node.MemorySegmentBytesIn;
+import io.sirix.node.MemorySegmentBytesOut;
 import io.sirix.node.NodeKind;
 import io.sirix.node.SirixDeweyID;
 
 import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
 import io.sirix.node.immutable.json.ImmutableObjectNumberNode;
+import io.sirix.node.interfaces.FlyweightNode;
 import io.sirix.node.interfaces.Node;
-import io.sirix.node.layout.NodeKindLayout;
-import io.sirix.node.layout.SlotLayoutAccessors;
-import io.sirix.node.layout.StructuralField;
 import io.sirix.node.interfaces.NumericValueNode;
-import io.sirix.node.interfaces.ReusableNodeProxy;
 import io.sirix.node.interfaces.StructNode;
 import io.sirix.node.interfaces.immutable.ImmutableJsonNode;
+import io.sirix.page.KeyValueLeafPage;
+import io.sirix.page.NodeFieldLayout;
+import io.sirix.page.PageLayout;
 import io.sirix.settings.Fixed;
 import net.openhft.hashing.LongHashFunction;
 import org.checkerframework.checker.nullness.qual.NonNull;
@@ -63,13 +65,11 @@
 /**
  * JSON Object Number node (direct child of ObjectKeyNode, no siblings).
  *
- * 

- * Uses primitive fields for efficient storage with delta+varint encoding.
- * 

- * 
+ * 
Uses primitive fields for efficient storage with delta+varint encoding.

+ *
  * @author Johannes Lichtenberger
  */
-public final class ObjectNumberNode implements StructNode, ImmutableJsonNode, NumericValueNode, ReusableNodeProxy {
+public final class ObjectNumberNode implements StructNode, ImmutableJsonNode, NumericValueNode, FlyweightNode {
 
   // Node identity (mutable for singleton reuse)
   private long nodeKey;
@@ -99,22 +99,56 @@ public final class ObjectNumberNode implements StructNode, ImmutableJsonNode, Nu
   private long lazyOffset;
   private boolean metadataParsed;
   private boolean valueParsed;
-  private boolean hasHash;
   private long valueOffset;
 
-  // Fixed-slot value encoding state (for read path via populateSingletonFromFixedSlot)
-  private boolean fixedValueEncoding; // Whether value comes from fixed-slot inline payload
-  private int fixedValueLength; // Length of inline payload bytes
+  // ==================== FLYWEIGHT BINDING (LeanStore page-direct access) ====================
+
+  /** Page MemorySegment when bound (null = primitive mode). */
+  private MemorySegment page;
+
+  /** Absolute byte offset of this record in the page (after HEAP_START + heapOffset). */
+  private long recordBase;
+
+  /** Absolute byte offset where the data region starts (recordBase + 1 + FIELD_COUNT). */
+  private long dataRegionStart;
+
+  /** Slot index in the page directory (for re-serialization). */
+  private int slotIndex;
+
+  /** True if this node is a factory-managed write singleton (must not be stored in records[]). */
+  private boolean writeSingleton;
+
+  /** Owning page for resize-in-place on varint width changes. */
+  private KeyValueLeafPage ownerPage;
+
+  /** Pre-allocated offset array reused across serializations (zero-alloc hot path). */
+  private final int[] heapOffsets;
+
+  private static final int FIELD_COUNT = NodeFieldLayout.OBJECT_NUMBER_VALUE_FIELD_COUNT;
+
+  /** Thread-local buffer for serializing Number payloads during serializeToHeap. */
+  private static final ThreadLocal TL_NUMBER_BUFFER =
+      ThreadLocal.withInitial(() -> new MemorySegmentBytesOut(64));
 
-  // Fixed-slot lazy metadata support
-  private long lazyBaseOffset;
-  private NodeKindLayout fixedSlotLayout;
+  /**
+   * Constructor for flyweight binding.
+   * All fields except nodeKey and hashFunction will be read from page memory after bind().
+   *
+   * @param nodeKey the node key
+   * @param hashFunction the hash function from resource config
+   */
+  public ObjectNumberNode(long nodeKey, LongHashFunction hashFunction) {
+    this.nodeKey = nodeKey;
+    this.hashFunction = hashFunction;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
 
   /**
    * Primary constructor with all primitive fields.
    */
-  public ObjectNumberNode(long nodeKey, long parentKey, int previousRevision, int lastModifiedRevision, long hash,
-      Number value, LongHashFunction hashFunction, byte[] deweyID) {
+  public ObjectNumberNode(long nodeKey, long parentKey, int previousRevision,
+      int lastModifiedRevision, long hash, Number value,
+      LongHashFunction hashFunction, byte[] deweyID) {
     this.nodeKey = nodeKey;
     this.parentKey = parentKey;
     this.previousRevision = previousRevision;
@@ -125,13 +159,15 @@ public ObjectNumberNode(long nodeKey, long parentKey, int previousRevision, int
     this.deweyIDBytes = deweyID;
     this.metadataParsed = true;
     this.valueParsed = true;
+    this.heapOffsets = new int[FIELD_COUNT];
   }
 
   /**
    * Constructor with SirixDeweyID instead of byte array.
    */
-  public ObjectNumberNode(long nodeKey, long parentKey, int previousRevision, int lastModifiedRevision, long hash,
-      Number value, LongHashFunction hashFunction, SirixDeweyID deweyID) {
+  public ObjectNumberNode(long nodeKey, long parentKey, int previousRevision,
+      int lastModifiedRevision, long hash, Number value,
+      LongHashFunction hashFunction, SirixDeweyID deweyID) {
     this.nodeKey = nodeKey;
     this.parentKey = parentKey;
     this.previousRevision = previousRevision;
@@ -142,6 +178,223 @@ public ObjectNumberNode(long nodeKey, long parentKey, int previousRevision, int
     this.sirixDeweyID = deweyID;
     this.metadataParsed = true;
     this.valueParsed = true;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
+
+  // ==================== STATIC WRITE / HEAP OFFSETS / DEWEYID ====================
+
+  /**
+   * Encode an ObjectNumberNode record directly to a MemorySegment from parameter values.
+   * Static -- reads nothing from any instance. Zero field intermediation.
+   *
+   * @param target     the target MemorySegment (reinterpreted slotted page)
+   * @param offset     absolute byte offset to write at
+   * @param heapOffsets pre-allocated offset array (reused, FIELD_COUNT elements)
+   * @param nodeKey    the node key (delta base for structural keys)
+   * @param parentKey  the parent node key
+   * @param prevRev    the previous revision number
+   * @param lastModRev the last modified revision number
+   * @param value      the Number value
+   * @return the total number of bytes written
+   */
+  public static int writeNewRecord(final MemorySegment target, final long offset,
+      final int[] heapOffsets, final long nodeKey,
+      final long parentKey, final int prevRev, final int lastModRev,
+      final Number value) {
+    long pos = offset;
+
+    // Write nodeKind byte
+    target.set(ValueLayout.JAVA_BYTE, pos, NodeKind.OBJECT_NUMBER_VALUE.getId());
+    pos++;
+
+    // Reserve space for offset table
+    final long offsetTableStart = pos;
+    pos += FIELD_COUNT;
+
+    // Data region start
+    final long dataStart = pos;
+
+    // Field 0: parentKey (delta-varint)
+    heapOffsets[NodeFieldLayout.OBJNUMVAL_PARENT_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, parentKey, nodeKey);
+
+    // Field 1: previousRevision (signed varint)
+    heapOffsets[NodeFieldLayout.OBJNUMVAL_PREV_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, prevRev);
+
+    // Field 2: lastModifiedRevision (signed varint)
+    heapOffsets[NodeFieldLayout.OBJNUMVAL_LAST_MOD_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, lastModRev);
+
+    // Field 3: payload (number: [numberType:1][numberData:variable])
+    heapOffsets[NodeFieldLayout.OBJNUMVAL_PAYLOAD] = (int) (pos - dataStart);
+    final MemorySegmentBytesOut numBuf = TL_NUMBER_BUFFER.get();
+    numBuf.clear();
+    NodeKind.serializeNumber(value, numBuf);
+    final int numBytes = (int) numBuf.position();
+    final MemorySegment numSegment = numBuf.getDestination();
+    MemorySegment.copy(numSegment, 0, target, pos, numBytes);
+    pos += numBytes;
+
+    // Write offset table
+    for (int i = 0; i < FIELD_COUNT; i++) {
+      target.set(ValueLayout.JAVA_BYTE, offsetTableStart + i, (byte) heapOffsets[i]);
+    }
+
+    return (int) (pos - offset);
+  }
+
+  /**
+   * Get the pre-allocated heap offsets array for use with static writeNewRecord.
+   */
+  public int[] getHeapOffsets() {
+    return heapOffsets;
+  }
+
+  /**
+   * Set DeweyID fields directly after creation, bypassing write-through.
+   * The DeweyID is already in the page trailer -- this just sets the Java cache fields.
+   */
+  public void setDeweyIDAfterCreation(final SirixDeweyID id, final byte[] bytes) {
+    this.sirixDeweyID = id;
+    this.deweyIDBytes = bytes;
+  }
+
+  // ==================== FLYWEIGHT BIND/UNBIND ====================
+
+  /**
+   * Bind this node as a flyweight to a page MemorySegment.
+   * When bound, getters/setters read/write directly to page memory via the offset table.
+   *
+   * @param page       the page MemorySegment
+   * @param recordBase absolute byte offset of this record in the page
+   * @param nodeKey    the node key (for delta decoding)
+   * @param slotIndex  the slot index in the page directory
+   */
+  public void bind(final MemorySegment page, final long recordBase, final long nodeKey,
+      final int slotIndex) {
+    this.page = page;
+    this.recordBase = recordBase;
+    this.nodeKey = nodeKey;
+    this.slotIndex = slotIndex;
+    this.dataRegionStart = recordBase + 1 + FIELD_COUNT;
+    this.hash = 0;
+    this.metadataParsed = true; // No lazy state when bound
+    this.valueParsed = false;   // Payload still needs lazy parsing from page
+    this.lazySource = null;
+  }
+
+  /**
+   * Unbind from page memory and materialize all fields into Java primitives.
+   * After unbind, the node operates in primitive mode.
+   */
+  public void unbind() {
+    if (page == null) {
+      return;
+    }
+    // Materialize all fields from page to Java primitives
+    final long nk = this.nodeKey;
+    this.parentKey = readDeltaField(NodeFieldLayout.OBJNUMVAL_PARENT_KEY, nk);
+    this.previousRevision = readSignedField(NodeFieldLayout.OBJNUMVAL_PREV_REVISION);
+    this.lastModifiedRevision = readSignedField(NodeFieldLayout.OBJNUMVAL_LAST_MOD_REVISION);
+    // Payload needs to be read from page before unbinding
+    if (!valueParsed) {
+      readPayloadFromPage();
+    }
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  @Override
+  public void clearBinding() {
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  /** Check if this node is bound to a page MemorySegment. */
+  public boolean isBound() {
+    return page != null;
+  }
+
+  @Override
+  public boolean isBoundTo(final MemorySegment page) {
+    return this.page == page;
+  }
+
+  @Override
+  public int getSlotIndex() {
+    return slotIndex;
+  }
+
+  // ==================== FLYWEIGHT FIELD READ HELPERS ====================
+
+  private long readDeltaField(final int fieldIndex, final long baseKey) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeDeltaFromSegment(page, dataRegionStart + fieldOff, baseKey);
+  }
+
+  private int readSignedField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeSignedFromSegment(page, dataRegionStart + fieldOff);
+  }
+
+  /**
+   * Resize a single field via raw-copy on the owning slotted page.
+   * Avoids the full unbind-to-primitives + re-serialize round-trip.
+   *
+   * @param fieldIndex the field index in the offset table (e.g. {@code OBJNUMVAL_PARENT_KEY})
+   * @param encoder    writes the new field value at the target offset
+   */
+  private void resizeRecordField(final int fieldIndex,
+      final DeltaVarIntCodec.FieldEncoder encoder) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex, fieldIndex, FIELD_COUNT, encoder);
+  }
+
+  // ==================== OWNER PAGE (for resize-in-place) ====================
+
+  @Override
+  public KeyValueLeafPage getOwnerPage() {
+    return ownerPage;
+  }
+
+  @Override
+  public void setOwnerPage(final KeyValueLeafPage ownerPage) {
+    this.ownerPage = ownerPage;
+  }
+
+  /**
+   * Read the Number payload directly from page memory when bound.
+   * Uses a MemorySegmentBytesIn wrapper to invoke NodeKind.deserializeNumber.
+   */
+  private void readPayloadFromPage() {
+    final int payloadFieldOff = page.get(ValueLayout.JAVA_BYTE,
+        recordBase + 1 + NodeFieldLayout.OBJNUMVAL_PAYLOAD) & 0xFF;
+    final long payloadStart = dataRegionStart + payloadFieldOff;
+
+    final MemorySegmentBytesIn bytesIn = new MemorySegmentBytesIn(page);
+    bytesIn.position(payloadStart);
+    this.value = NodeKind.deserializeNumber(bytesIn);
+    this.valueParsed = true;
+  }
+
+  // ==================== SERIALIZE TO HEAP ====================
+
+  /**
+   * Serialize this node from Java fields. Delegates to static writeNewRecord.
+   *
+   * @param target the target MemorySegment
+   * @param offset the absolute byte offset to write at
+   * @return the total number of bytes written
+   */
+  public int serializeToHeap(final MemorySegment target, final long offset) {
+    if (!metadataParsed) {
+      parseMetadataFields();
+    }
+    if (!valueParsed) {
+      parseValueField();
+    }
+    return writeNewRecord(target, offset, heapOffsets, nodeKey,
+        parentKey, previousRevision, lastModifiedRevision, value);
   }
 
   @Override
@@ -156,16 +409,33 @@ public long getNodeKey() {
 
   @Override
   public long getParentKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.OBJNUMVAL_PARENT_KEY, nodeKey);
+    }
     return parentKey;
   }
 
   public void setParentKey(final long parentKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJNUMVAL_PARENT_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(parentKey, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, parentKey, nodeKey);
+        return;
+      }
+      resizeRecordField(NodeFieldLayout.OBJNUMVAL_PARENT_KEY,
+          (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, parentKey, nodeKey));
+      return;
+    }
     this.parentKey = parentKey;
   }
 
   @Override
   public boolean hasParent() {
-    return parentKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getParentKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
@@ -178,26 +448,73 @@ public void setTypeKey(final int typeKey) {}
 
   @Override
   public void setDeweyID(final SirixDeweyID id) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.sirixDeweyID = id;
+      this.deweyIDBytes = null;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
     this.sirixDeweyID = id;
     this.deweyIDBytes = null;
   }
 
+  @Override
+  public void setDeweyIDBytes(final byte[] bytes) {
+    this.deweyIDBytes = bytes;
+    this.sirixDeweyID = null;
+  }
+
   @Override
   public void setPreviousRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJNUMVAL_PREV_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizeRecordField(NodeFieldLayout.OBJNUMVAL_PREV_REVISION,
+          (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+      return;
+    }
     this.previousRevision = revision;
   }
 
   @Override
   public void setLastModifiedRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJNUMVAL_LAST_MOD_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizeRecordField(NodeFieldLayout.OBJNUMVAL_LAST_MOD_REVISION,
+          (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+      return;
+    }
     this.lastModifiedRevision = revision;
   }
 
   @Override
   public long getHash() {
-    if (!metadataParsed) {
-      parseMetadataFields();
+    if (hash != 0L) {
+      return hash;
     }
-    return hash;
+    if (hashFunction != null) {
+      return computeHash(Bytes.threadLocalHashBuffer());
+    }
+    return 0L;
   }
 
   @Override
@@ -208,7 +525,9 @@ public void setHash(final long hash) {
   @Override
   public long computeHash(final BytesOut bytes) {
     bytes.clear();
-    bytes.writeLong(getNodeKey()).writeLong(getParentKey()).writeByte(getKind().getId());
+    bytes.writeLong(getNodeKey())
+         .writeLong(getParentKey())
+         .writeByte(getKind().getId());
 
     final Number number = getValue();
     switch (number) {
@@ -267,15 +586,27 @@ public long getDescendantCount() {
   public void setDescendantCount(final long descendantCount) {}
 
   public Number getValue() {
-    if (!valueParsed) {
+    if (page != null && !valueParsed) {
+      readPayloadFromPage();
+    } else if (!valueParsed) {
       parseValueField();
     }
     return value;
   }
 
   public void setValue(final Number value) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.value = value;
+      this.valueParsed = true;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
+    if (page != null) unbind();
     this.value = value;
-    this.fixedValueEncoding = false;
     this.valueParsed = true;
   }
 
@@ -313,6 +644,9 @@ public boolean hasRightSibling() {
 
   @Override
   public int getPreviousRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.OBJNUMVAL_PREV_REVISION);
+    }
     if (!metadataParsed) {
       parseMetadataFields();
     }
@@ -321,6 +655,9 @@ public int getPreviousRevisionNumber() {
 
   @Override
   public int getLastModifiedRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.OBJNUMVAL_LAST_MOD_REVISION);
+    }
     if (!metadataParsed) {
       parseMetadataFields();
     }
@@ -336,13 +673,10 @@ public void setNodeKey(final long nodeKey) {
     this.nodeKey = nodeKey;
   }
 
-  public void setDeweyIDBytes(final byte[] deweyIDBytes) {
-    this.deweyIDBytes = deweyIDBytes;
-    this.sirixDeweyID = null;
-  }
-
   public void readFrom(final BytesIn source, final long nodeKey, final byte[] deweyId,
-      final LongHashFunction hashFunction, final ResourceConfiguration config) {
+                       final LongHashFunction hashFunction, final ResourceConfiguration config) {
+    // Unbind flyweight — ensures getters use Java fields, not stale page reference
+    this.page = null;
     this.nodeKey = nodeKey;
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyId;
@@ -356,7 +690,6 @@ public void readFrom(final BytesIn source, final long nodeKey, final byte[] d
     this.lazyOffset = source.position();
     this.metadataParsed = false;
     this.valueParsed = false;
-    this.hasHash = config.hashType != HashType.NONE;
     this.valueOffset = 0;
 
     this.previousRevision = 0;
@@ -365,61 +698,20 @@ public void readFrom(final BytesIn source, final long nodeKey, final byte[] d
     this.value = null;
   }
 
-  /**
-   * Populate this singleton from fixed-slot inline payload (zero allocation). Sets up lazy value
-   * parsing from the fixed-slot MemorySegment. CRITICAL: Resets hash to 0 — caller MUST call
-   * setHash() AFTER this method.
-   *
-   * @param source the slot data (MemorySegment) containing inline payload
-   * @param valueOffset byte offset within source where payload bytes start
-   * @param valueLength length of payload bytes
-   */
-  public void setLazyNumberValue(final Object source, final long valueOffset, final int valueLength) {
-    this.lazySource = source;
-    this.valueOffset = valueOffset;
-    this.metadataParsed = true;
-    this.valueParsed = false;
-    this.fixedValueEncoding = true;
-    this.fixedValueLength = valueLength;
-    this.value = null;
-    this.hash = 0L;
-  }
-
-  public void bindFixedSlotLazy(final MemorySegment slotData, final long baseOffset, final NodeKindLayout layout) {
-    this.lazyBaseOffset = baseOffset;
-    this.fixedSlotLayout = layout;
-    this.metadataParsed = false;
-  }
-
   private void parseMetadataFields() {
     if (metadataParsed) {
       return;
     }
 
-    if (fixedSlotLayout != null) {
-      final MemorySegment sd = (MemorySegment) lazySource;
-      final NodeKindLayout ly = fixedSlotLayout;
-      final long off = this.lazyBaseOffset;
-      this.previousRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.PREVIOUS_REVISION);
-      this.lastModifiedRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.LAST_MODIFIED_REVISION);
-      this.hash = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.HASH);
-      this.fixedSlotLayout = null;
-      this.metadataParsed = true;
-      return;
-    }
-
     if (lazySource == null) {
       metadataParsed = true;
       return;
     }
 
-    final BytesIn bytesIn = createBytesIn(lazyOffset);
+    BytesIn bytesIn = createBytesIn(lazyOffset);
 
     this.previousRevision = DeltaVarIntCodec.decodeSigned(bytesIn);
     this.lastModifiedRevision = DeltaVarIntCodec.decodeSigned(bytesIn);
-    if (hasHash) {
-      this.hash = bytesIn.readLong();
-    }
     this.valueOffset = bytesIn.position();
     this.metadataParsed = true;
   }
@@ -429,18 +721,6 @@ private void parseValueField() {
       return;
     }
 
-    // Fixed-slot inline payload path (from setLazyNumberValue)
-    if (fixedValueEncoding) {
-      if (fixedValueLength > 0) {
-        final BytesIn bytesIn = createBytesIn(valueOffset);
-        this.value = NodeKind.deserializeNumber(bytesIn);
-      } else {
-        this.value = 0;
-      }
-      this.valueParsed = true;
-      return;
-    }
-
     if (!metadataParsed) {
       parseMetadataFields();
     }
@@ -450,7 +730,7 @@ private void parseValueField() {
       return;
     }
 
-    final BytesIn bytesIn = createBytesIn(valueOffset);
+    BytesIn bytesIn = createBytesIn(valueOffset);
     this.value = NodeKind.deserializeNumber(bytesIn);
     this.valueParsed = true;
   }
@@ -469,17 +749,44 @@ private BytesIn createBytesIn(long offset) {
     }
   }
 
+  /**
+   * Create a deep copy snapshot of this node.
+   * Forces parsing of all lazy fields since snapshot must be independent.
+   */
   public ObjectNumberNode toSnapshot() {
+    if (page != null) {
+      // Bound mode: read all fields from page
+      if (!valueParsed) {
+        readPayloadFromPage();
+      }
+      return new ObjectNumberNode(nodeKey,
+          readDeltaField(NodeFieldLayout.OBJNUMVAL_PARENT_KEY, nodeKey),
+          readSignedField(NodeFieldLayout.OBJNUMVAL_PREV_REVISION),
+          readSignedField(NodeFieldLayout.OBJNUMVAL_LAST_MOD_REVISION),
+          hash,
+          value,
+          hashFunction,
+          getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null);
+    }
     if (!metadataParsed) {
       parseMetadataFields();
     }
     if (!valueParsed) {
       parseValueField();
     }
-    return new ObjectNumberNode(nodeKey, parentKey, previousRevision, lastModifiedRevision, hash, value, hashFunction,
-        deweyIDBytes != null
-            ? deweyIDBytes.clone()
-            : null);
+    return new ObjectNumberNode(nodeKey, parentKey, previousRevision, lastModifiedRevision,
+        hash, value, hashFunction,
+        getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null);
+  }
+
+  @Override
+  public boolean isWriteSingleton() {
+    return writeSingleton;
+  }
+
+  @Override
+  public void setWriteSingleton(final boolean writeSingleton) {
+    this.writeSingleton = writeSingleton;
   }
 
   @Override
@@ -524,6 +831,8 @@ public boolean equals(final Object obj) {
     if (!(obj instanceof final ObjectNumberNode other))
       return false;
 
-    return nodeKey == other.nodeKey && parentKey == other.parentKey && Objects.equal(value, other.value);
+    return nodeKey == other.nodeKey
+        && parentKey == other.parentKey
+        && Objects.equal(value, other.value);
   }
 }
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/json/ObjectStringNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/json/ObjectStringNode.java
index e1b224d99..9b777d98a 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/json/ObjectStringNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/json/ObjectStringNode.java
@@ -31,9 +31,9 @@
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Objects;
 import io.sirix.access.ResourceConfiguration;
-import io.sirix.access.trx.node.HashType;
 import io.sirix.api.visitor.JsonNodeVisitor;
 import io.sirix.api.visitor.VisitResult;
+import io.sirix.node.Bytes;
 import io.sirix.node.ByteArrayBytesIn;
 import io.sirix.node.BytesIn;
 import io.sirix.node.BytesOut;
@@ -43,17 +43,19 @@
 import io.sirix.node.SirixDeweyID;
 
 import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
 import io.sirix.node.immutable.json.ImmutableObjectStringNode;
+import io.sirix.node.interfaces.FlyweightNode;
 import io.sirix.node.interfaces.Node;
-import io.sirix.node.layout.NodeKindLayout;
-import io.sirix.node.layout.SlotLayoutAccessors;
-import io.sirix.node.layout.StructuralField;
-import io.sirix.node.interfaces.ReusableNodeProxy;
 import io.sirix.node.interfaces.StructNode;
 import io.sirix.node.interfaces.ValueNode;
 import io.sirix.node.interfaces.immutable.ImmutableJsonNode;
+import io.sirix.page.KeyValueLeafPage;
+import io.sirix.page.NodeFieldLayout;
+import io.sirix.page.PageLayout;
 import io.sirix.settings.Constants;
 import io.sirix.settings.Fixed;
+import io.sirix.settings.StringCompressionType;
 import io.sirix.utils.FSSTCompressor;
 import net.openhft.hashing.LongHashFunction;
 import org.checkerframework.checker.nullness.qual.NonNull;
@@ -62,33 +64,31 @@
 /**
  * JSON Object String node (direct child of ObjectKeyNode, no siblings).
  *
- * 

- * Uses primitive fields for efficient storage with delta+varint encoding.
- * 

+ * 
Uses primitive fields for efficient storage with delta+varint encoding.

  * 
  * @author Johannes Lichtenberger
  */
-public final class ObjectStringNode implements StructNode, ValueNode, ImmutableJsonNode, ReusableNodeProxy {
+public final class ObjectStringNode implements StructNode, ValueNode, ImmutableJsonNode, FlyweightNode {
 
   // Node identity (mutable for singleton reuse)
   private long nodeKey;
-
+  
   // Mutable structural fields (only parent, no siblings for object values)
   private long parentKey;
-
+  
   // Mutable revision tracking
   private int previousRevision;
   private int lastModifiedRevision;
-
+  
   // Mutable hash
   private long hash;
-
+  
   // String value (stored as bytes)
   private byte[] value;
-
+  
   // Hash function for computing node hashes (mutable for singleton reuse)
   private LongHashFunction hashFunction;
-
+  
   // DeweyID support (lazily parsed)
   private SirixDeweyID sirixDeweyID;
   private byte[] deweyIDBytes;
@@ -98,44 +98,66 @@ public final class ObjectStringNode implements StructNode, ValueNode, ImmutableJ
   private boolean isCompressed;
   /** FSST symbol table for decompression (shared from KeyValueLeafPage) */
   private byte[] fsstSymbolTable;
-  /** Pre-parsed FSST symbol table (avoids re-parsing on every decode) */
-  private byte[][] parsedFsstSymbols;
   /** Decompressed value (lazy allocated on first access if compressed) */
   private byte[] decodedValue;
 
   // Lazy parsing state (for singleton reuse optimization)
   // Two-stage lazy parsing: metadata (cheap) vs value (expensive byte[] allocation)
-  private Object lazySource; // Source for lazy parsing (MemorySegment or byte[])
-  private long lazyOffset; // Offset where lazy metadata fields start
-  private boolean metadataParsed; // Whether prevRev, lastModRev, hash are parsed
-  private boolean valueParsed; // Whether value byte[] is parsed
-  private boolean hasHash; // Whether hash is stored (from config)
-  private long valueOffset; // Offset where value starts (after metadata)
-
-  // Fixed-slot value encoding state (for read path via populateSingletonFromFixedSlot)
-  private boolean fixedValueEncoding; // Whether value comes from fixed-slot inline payload
-  private int fixedValueLength; // Length of inline payload bytes
-  private boolean fixedValueCompressed; // Whether inline payload is FSST compressed
-
-  // Fixed-slot lazy metadata support
-  private long lazyBaseOffset;
-  private NodeKindLayout fixedSlotLayout;
+  private Object lazySource;            // Source for lazy parsing (MemorySegment or byte[])
+  private long lazyOffset;              // Offset where lazy metadata fields start
+  private boolean metadataParsed;       // Whether prevRev, lastModRev, hash are parsed
+  private boolean valueParsed;          // Whether value byte[] is parsed
+  private long valueOffset;             // Offset where value starts (after metadata)
+
+  // ==================== FLYWEIGHT BINDING (LeanStore page-direct access) ====================
+  private MemorySegment page;
+  private long recordBase;
+  private long dataRegionStart;
+  private int slotIndex;
+
+  /** True if this node is a factory-managed write singleton (must not be stored in records[]). */
+  private boolean writeSingleton;
+
+  /** Owning page for resize-in-place on varint width changes. */
+  private KeyValueLeafPage ownerPage;
+
+  /** Pre-allocated offset array reused across serializations (zero-alloc hot path). */
+  private final int[] heapOffsets;
+
+  private static final int FIELD_COUNT = NodeFieldLayout.OBJECT_STRING_VALUE_FIELD_COUNT;
+
+  /**
+   * Constructor for flyweight binding.
+   * All fields except nodeKey and hashFunction will be read from page memory after bind().
+   *
+   * @param nodeKey the node key
+   * @param hashFunction the hash function from resource config
+   */
+  public ObjectStringNode(long nodeKey, LongHashFunction hashFunction) {
+    this.nodeKey = nodeKey;
+    this.hashFunction = hashFunction;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
 
   /**
-   * Primary constructor with all primitive fields. All fields are already parsed - no lazy loading
-   * needed.
+   * Primary constructor with all primitive fields.
+   * All fields are already parsed - no lazy loading needed.
    */
-  public ObjectStringNode(long nodeKey, long parentKey, int previousRevision, int lastModifiedRevision, long hash,
-      byte[] value, LongHashFunction hashFunction, byte[] deweyID) {
-    this(nodeKey, parentKey, previousRevision, lastModifiedRevision, hash, value, hashFunction, deweyID, false, null);
+  public ObjectStringNode(long nodeKey, long parentKey, int previousRevision,
+      int lastModifiedRevision, long hash, byte[] value,
+      LongHashFunction hashFunction, byte[] deweyID) {
+    this(nodeKey, parentKey, previousRevision, lastModifiedRevision, hash, value,
+        hashFunction, deweyID, false, null);
   }
 
   /**
-   * Primary constructor with all primitive fields and compression support. All fields are already
-   * parsed - no lazy loading needed.
+   * Primary constructor with all primitive fields and compression support.
+   * All fields are already parsed - no lazy loading needed.
    */
-  public ObjectStringNode(long nodeKey, long parentKey, int previousRevision, int lastModifiedRevision, long hash,
-      byte[] value, LongHashFunction hashFunction, byte[] deweyID, boolean isCompressed, byte[] fsstSymbolTable) {
+  public ObjectStringNode(long nodeKey, long parentKey, int previousRevision,
+      int lastModifiedRevision, long hash, byte[] value,
+      LongHashFunction hashFunction, byte[] deweyID,
+      boolean isCompressed, byte[] fsstSymbolTable) {
     this.nodeKey = nodeKey;
     this.parentKey = parentKey;
     this.previousRevision = previousRevision;
@@ -149,23 +171,28 @@ public ObjectStringNode(long nodeKey, long parentKey, int previousRevision, int
     // Constructed with all values - mark as fully parsed
     this.metadataParsed = true;
     this.valueParsed = true;
+    this.heapOffsets = new int[FIELD_COUNT];
   }
 
   /**
-   * Constructor with SirixDeweyID instead of byte array. All fields are already parsed - no lazy
-   * loading needed.
+   * Constructor with SirixDeweyID instead of byte array.
+   * All fields are already parsed - no lazy loading needed.
    */
-  public ObjectStringNode(long nodeKey, long parentKey, int previousRevision, int lastModifiedRevision, long hash,
-      byte[] value, LongHashFunction hashFunction, SirixDeweyID deweyID) {
-    this(nodeKey, parentKey, previousRevision, lastModifiedRevision, hash, value, hashFunction, deweyID, false, null);
+  public ObjectStringNode(long nodeKey, long parentKey, int previousRevision,
+      int lastModifiedRevision, long hash, byte[] value,
+      LongHashFunction hashFunction, SirixDeweyID deweyID) {
+    this(nodeKey, parentKey, previousRevision, lastModifiedRevision, hash, value,
+        hashFunction, deweyID, false, null);
   }
 
   /**
-   * Constructor with SirixDeweyID and compression support. All fields are already parsed - no lazy
-   * loading needed.
+   * Constructor with SirixDeweyID and compression support.
+   * All fields are already parsed - no lazy loading needed.
    */
-  public ObjectStringNode(long nodeKey, long parentKey, int previousRevision, int lastModifiedRevision, long hash,
-      byte[] value, LongHashFunction hashFunction, SirixDeweyID deweyID, boolean isCompressed, byte[] fsstSymbolTable) {
+  public ObjectStringNode(long nodeKey, long parentKey, int previousRevision,
+      int lastModifiedRevision, long hash, byte[] value,
+      LongHashFunction hashFunction, SirixDeweyID deweyID,
+      boolean isCompressed, byte[] fsstSymbolTable) {
     this.nodeKey = nodeKey;
     this.parentKey = parentKey;
     this.previousRevision = previousRevision;
@@ -179,6 +206,7 @@ public ObjectStringNode(long nodeKey, long parentKey, int previousRevision, int
     // Constructed with all values - mark as fully parsed
     this.metadataParsed = true;
     this.valueParsed = true;
+    this.heapOffsets = new int[FIELD_COUNT];
   }
 
   @Override
@@ -193,16 +221,34 @@ public long getNodeKey() {
 
   @Override
   public long getParentKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.OBJSTRVAL_PARENT_KEY, nodeKey);
+    }
     return parentKey;
   }
 
   public void setParentKey(final long parentKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJSTRVAL_PARENT_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(parentKey, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, parentKey, nodeKey);
+        return;
+      }
+      ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+          NodeFieldLayout.OBJSTRVAL_PARENT_KEY, FIELD_COUNT,
+          (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, parentKey, nodeKey));
+      return;
+    }
     this.parentKey = parentKey;
   }
 
   @Override
   public boolean hasParent() {
-    return parentKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getParentKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
@@ -215,26 +261,75 @@ public void setTypeKey(final int typeKey) {}
 
   @Override
   public void setDeweyID(final SirixDeweyID id) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.sirixDeweyID = id;
+      this.deweyIDBytes = null;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
     this.sirixDeweyID = id;
     this.deweyIDBytes = null;
   }
 
+  @Override
+  public void setDeweyIDBytes(final byte[] bytes) {
+    this.deweyIDBytes = bytes;
+    this.sirixDeweyID = null;
+  }
+
   @Override
   public void setPreviousRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJSTRVAL_PREV_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+          NodeFieldLayout.OBJSTRVAL_PREV_REVISION, FIELD_COUNT,
+          (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+      return;
+    }
     this.previousRevision = revision;
   }
 
   @Override
   public void setLastModifiedRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.OBJSTRVAL_LAST_MOD_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+          NodeFieldLayout.OBJSTRVAL_LAST_MOD_REVISION, FIELD_COUNT,
+          (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+      return;
+    }
     this.lastModifiedRevision = revision;
   }
 
   @Override
   public long getHash() {
-    if (!metadataParsed) {
-      parseMetadataFields();
+    if (hash != 0L) {
+      return hash;
     }
-    return hash;
+    if (hashFunction != null) {
+      return computeHash(Bytes.threadLocalHashBuffer());
+    }
+    return 0L;
   }
 
   @Override
@@ -245,9 +340,14 @@ public void setHash(final long hash) {
   @Override
   public long computeHash(final BytesOut bytes) {
     bytes.clear();
-    bytes.writeLong(getNodeKey()).writeLong(getParentKey()).writeByte(getKind().getId());
+    bytes.writeLong(getNodeKey())
+         .writeLong(getParentKey())
+         .writeByte(getKind().getId());
 
-    bytes.writeUtf8(getValue());
+    final byte[] rawValue = getRawValue();
+    if (rawValue != null) {
+      bytes.write(rawValue);
+    }
 
     return bytes.hashDirect(hashFunction);
   }
@@ -256,67 +356,68 @@ public long computeHash(final BytesOut bytes) {
   public long getRightSiblingKey() {
     return Fixed.NULL_NODE_KEY.getStandardProperty();
   }
-
+  
   public void setRightSiblingKey(final long rightSibling) {}
 
   @Override
   public long getLeftSiblingKey() {
     return Fixed.NULL_NODE_KEY.getStandardProperty();
   }
-
+  
   public void setLeftSiblingKey(final long leftSibling) {}
 
   @Override
   public long getFirstChildKey() {
     return Fixed.NULL_NODE_KEY.getStandardProperty();
   }
-
+  
   public void setFirstChildKey(final long firstChild) {}
 
   @Override
   public long getLastChildKey() {
     return Fixed.NULL_NODE_KEY.getStandardProperty();
   }
-
+  
   public void setLastChildKey(final long lastChild) {}
 
   @Override
   public long getChildCount() {
     return 0;
   }
-
+  
   public void setChildCount(final long childCount) {}
 
   @Override
   public long getDescendantCount() {
     return 0;
   }
-
+  
   public void setDescendantCount(final long descendantCount) {}
 
   @Override
   public byte[] getRawValue() {
-    if (!valueParsed) {
+    if (page != null && !valueParsed) {
+      readPayloadFromPage();
+    } else if (!valueParsed) {
       parseValueField();
     }
-    // If compressed, decode on first access using pre-parsed symbols when available
+    // If compressed, decode on first access
     if (isCompressed && decodedValue == null && value != null) {
-      final byte[][] parsed = parsedFsstSymbols;
-      decodedValue = (parsed != null) ? FSSTCompressor.decode(value, parsed) : FSSTCompressor.decode(value, fsstSymbolTable);
+      decodedValue = FSSTCompressor.decode(value, fsstSymbolTable);
     }
-    return isCompressed
-        ? decodedValue
-        : value;
+    return isCompressed ? decodedValue : value;
   }
 
   /**
-   * Get the raw (possibly compressed) value bytes without FSST decoding. Use this for serialization
-   * to preserve compression.
-   * 
+   * Get the raw (possibly compressed) value bytes without FSST decoding.
+   * Use this for serialization to preserve compression.
+   *
    * @return the raw bytes as stored, possibly FSST compressed
    */
   public byte[] getRawValueWithoutDecompression() {
-    if (!valueParsed) {
+    if (page != null && !valueParsed) {
+      readPayloadFromPage();
+    } else if (!valueParsed) {
       parseValueField();
     }
     return value;
@@ -324,25 +425,49 @@ public byte[] getRawValueWithoutDecompression() {
 
   @Override
   public void setRawValue(final byte[] value) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.value = value;
+      this.decodedValue = null;
+      this.valueParsed = true;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
+    if (page != null) unbind();
     this.value = value;
     this.decodedValue = null;
-    this.fixedValueEncoding = false;
     this.valueParsed = true;
   }
 
   /**
    * Set the raw value with compression information.
-   *
+   * 
    * @param value the value bytes (possibly compressed)
    * @param isCompressed true if value is FSST compressed
    * @param fsstSymbolTable the symbol table for decompression (or null if not compressed)
    */
   public void setRawValue(final byte[] value, boolean isCompressed, byte[] fsstSymbolTable) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.value = value;
+      this.isCompressed = isCompressed;
+      this.fsstSymbolTable = fsstSymbolTable;
+      this.decodedValue = null;
+      this.valueParsed = true;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
+    if (page != null) unbind();
     this.value = value;
     this.isCompressed = isCompressed;
     this.fsstSymbolTable = fsstSymbolTable;
     this.decodedValue = null;
-    this.fixedValueEncoding = false;
     this.valueParsed = true;
   }
 
@@ -352,12 +477,15 @@ public void setRawValue(final byte[] value, boolean isCompressed, byte[] fsstSym
    * @return true if compressed
    */
   public boolean isCompressed() {
+    if (page != null && !valueParsed) {
+      readPayloadFromPage();
+    }
     return isCompressed;
   }
 
   /**
    * Set compression state.
-   * 
+   *
    * @param isCompressed true if value is compressed
    */
   public void setCompressed(boolean isCompressed) {
@@ -375,24 +503,11 @@ public byte[] getFsstSymbolTable() {
 
   /**
    * Set the FSST symbol table.
-   *
+   * 
    * @param fsstSymbolTable the symbol table
    */
   public void setFsstSymbolTable(byte[] fsstSymbolTable) {
     this.fsstSymbolTable = fsstSymbolTable;
-    this.parsedFsstSymbols = null;
-    this.decodedValue = null;
-  }
-
-  /**
-   * Set the FSST symbol table with pre-parsed symbols to avoid redundant parsing.
-   *
-   * @param fsstSymbolTable the raw symbol table bytes
-   * @param parsedFsstSymbols the pre-parsed symbol arrays
-   */
-  public void setFsstSymbolTable(byte[] fsstSymbolTable, byte[][] parsedFsstSymbols) {
-    this.fsstSymbolTable = fsstSymbolTable;
-    this.parsedFsstSymbols = parsedFsstSymbols;
     this.decodedValue = null;
   }
 
@@ -437,6 +552,9 @@ public boolean hasRightSibling() {
 
   @Override
   public int getPreviousRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.OBJSTRVAL_PREV_REVISION);
+    }
     if (!metadataParsed) {
       parseMetadataFields();
     }
@@ -445,6 +563,9 @@ public int getPreviousRevisionNumber() {
 
   @Override
   public int getLastModifiedRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.OBJSTRVAL_LAST_MOD_REVISION);
+    }
     if (!metadataParsed) {
       parseMetadataFields();
     }
@@ -460,18 +581,15 @@ public void setNodeKey(final long nodeKey) {
     this.nodeKey = nodeKey;
   }
 
-  public void setDeweyIDBytes(final byte[] deweyIDBytes) {
-    this.deweyIDBytes = deweyIDBytes;
-    this.sirixDeweyID = null;
-  }
-
   /**
-   * Populate this node from a BytesIn source for singleton reuse. LAZY OPTIMIZATION: Only parses
-   * structural field (parentKey) immediately. Two-stage lazy parsing: metadata (cheap) vs value
-   * (expensive byte[] allocation).
+   * Populate this node from a BytesIn source for singleton reuse.
+   * LAZY OPTIMIZATION: Only parses structural field (parentKey) immediately.
+   * Two-stage lazy parsing: metadata (cheap) vs value (expensive byte[] allocation).
    */
   public void readFrom(final BytesIn source, final long nodeKey, final byte[] deweyId,
-      final LongHashFunction hashFunction, final ResourceConfiguration config) {
+                       final LongHashFunction hashFunction, final ResourceConfiguration config) {
+    // Unbind flyweight — ensures getters use Java fields, not stale page reference
+    this.page = null;
     this.nodeKey = nodeKey;
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyId;
@@ -479,87 +597,42 @@ public void readFrom(final BytesIn source, final long nodeKey, final byte[] d
 
     // STRUCTURAL FIELD - parse immediately (parentKey is the only one for leaf nodes)
     this.parentKey = DeltaVarIntCodec.decodeDelta(source, nodeKey);
-
+    
     // Store state for lazy parsing - DON'T parse remaining fields yet
     this.lazySource = source.getSource();
     this.lazyOffset = source.position();
     this.metadataParsed = false;
     this.valueParsed = false;
-    this.hasHash = config.hashType != HashType.NONE;
     this.valueOffset = 0;
-
+    
     // Initialize lazy fields to defaults (will be populated on demand)
     this.previousRevision = 0;
     this.lastModifiedRevision = 0;
     this.hash = 0;
     this.value = null;
   }
-
+  
   /**
-   * Populate this singleton from fixed-slot inline payload (zero allocation). Sets up lazy value
-   * parsing from the fixed-slot MemorySegment. CRITICAL: Resets hash to 0 — caller MUST call
-   * setHash() AFTER this method.
-   *
-   * @param source the slot data (MemorySegment) containing inline payload
-   * @param valueOffset byte offset within source where payload bytes start
-   * @param valueLength length of payload bytes
-   * @param compressed whether the payload is FSST compressed
+   * Parse metadata fields on demand (cheap - just varints and optionally a long).
    */
-  public void setLazyRawValue(final Object source, final long valueOffset, final int valueLength,
-      final boolean compressed) {
-    this.lazySource = source;
-    this.valueOffset = valueOffset;
-    this.metadataParsed = true;
-    this.valueParsed = false;
-    this.fixedValueEncoding = true;
-    this.fixedValueLength = valueLength;
-    this.fixedValueCompressed = compressed;
-    this.value = null;
-    this.fsstSymbolTable = null;
-    this.parsedFsstSymbols = null;
-    this.decodedValue = null;
-    this.hash = 0L;
-  }
-
-  public void bindFixedSlotLazy(final MemorySegment slotData, final long baseOffset, final NodeKindLayout layout) {
-    this.lazyBaseOffset = baseOffset;
-    this.fixedSlotLayout = layout;
-    this.metadataParsed = false;
-  }
-
   private void parseMetadataFields() {
     if (metadataParsed) {
       return;
     }
-
-    if (fixedSlotLayout != null) {
-      final MemorySegment sd = (MemorySegment) lazySource;
-      final NodeKindLayout ly = fixedSlotLayout;
-      final long off = this.lazyBaseOffset;
-      this.previousRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.PREVIOUS_REVISION);
-      this.lastModifiedRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.LAST_MODIFIED_REVISION);
-      this.hash = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.HASH);
-      this.fixedSlotLayout = null;
-      this.metadataParsed = true;
-      return;
-    }
-
+    
     if (lazySource == null) {
       metadataParsed = true;
       return;
     }
-
+    
     BytesIn bytesIn = createBytesIn(lazyOffset);
-
+    
     this.previousRevision = DeltaVarIntCodec.decodeSigned(bytesIn);
     this.lastModifiedRevision = DeltaVarIntCodec.decodeSigned(bytesIn);
-    if (hasHash) {
-      this.hash = bytesIn.readLong();
-    }
     this.valueOffset = bytesIn.position();
     this.metadataParsed = true;
   }
-
+  
   /**
    * Parse value field on demand (expensive - allocates byte[]).
    */
@@ -567,40 +640,28 @@ private void parseValueField() {
     if (valueParsed) {
       return;
     }
-
-    // Fixed-slot inline payload path (from setLazyRawValue)
-    if (fixedValueEncoding) {
-      final BytesIn bytesIn = createBytesIn(valueOffset);
-      this.isCompressed = fixedValueCompressed;
-      this.value = new byte[fixedValueLength];
-      if (fixedValueLength > 0) {
-        bytesIn.read(this.value, 0, fixedValueLength);
-      }
-      this.valueParsed = true;
-      return;
-    }
-
+    
     if (!metadataParsed) {
       parseMetadataFields();
     }
-
+    
     if (lazySource == null) {
       valueParsed = true;
       return;
     }
-
-    final BytesIn bytesIn = createBytesIn(valueOffset);
-
+    
+    BytesIn bytesIn = createBytesIn(valueOffset);
+    
     // Read compression flag (1 byte: 0 = none, 1 = FSST)
-    final byte compressionByte = bytesIn.readByte();
+    byte compressionByte = bytesIn.readByte();
     this.isCompressed = compressionByte == 1;
-
-    final int length = DeltaVarIntCodec.decodeSigned(bytesIn);
+    
+    int length = DeltaVarIntCodec.decodeSigned(bytesIn);
     this.value = new byte[length];
     bytesIn.read(this.value);
     this.valueParsed = true;
   }
-
+  
   private BytesIn createBytesIn(long offset) {
     if (lazySource instanceof MemorySegment segment) {
       var bytesIn = new MemorySegmentBytesIn(segment);
@@ -615,26 +676,262 @@ private BytesIn createBytesIn(long offset) {
     }
   }
 
+  // ==================== STATIC WRITE / HEAP OFFSETS / DEWEYID ====================
+
+  /**
+   * Encode an ObjectStringNode record directly to a MemorySegment from parameter values.
+   * Static -- reads nothing from any instance. Zero field intermediation.
+   *
+   * @param target       the target MemorySegment (reinterpreted slotted page)
+   * @param offset       absolute byte offset to write at
+   * @param heapOffsets  pre-allocated offset array (reused, FIELD_COUNT elements)
+   * @param nodeKey      the node key (delta base for structural keys)
+   * @param parentKey    the parent node key
+   * @param prevRev      the previous revision number
+   * @param lastModRev   the last modified revision number
+   * @param rawValue     the raw string value bytes (possibly compressed)
+   * @param isCompressed whether the value is FSST compressed
+   * @return the total number of bytes written
+   */
+  public static int writeNewRecord(final MemorySegment target, final long offset,
+      final int[] heapOffsets, final long nodeKey,
+      final long parentKey, final int prevRev, final int lastModRev,
+      final byte[] rawValue, final boolean isCompressed) {
+    long pos = offset;
+
+    // Write nodeKind byte
+    target.set(ValueLayout.JAVA_BYTE, pos, NodeKind.OBJECT_STRING_VALUE.getId());
+    pos++;
+
+    // Reserve space for offset table
+    final long offsetTableStart = pos;
+    pos += FIELD_COUNT;
+
+    // Data region start
+    final long dataStart = pos;
+
+    // Field 0: parentKey (delta-varint)
+    heapOffsets[NodeFieldLayout.OBJSTRVAL_PARENT_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, parentKey, nodeKey);
+
+    // Field 1: previousRevision (signed varint)
+    heapOffsets[NodeFieldLayout.OBJSTRVAL_PREV_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, prevRev);
+
+    // Field 2: lastModifiedRevision (signed varint)
+    heapOffsets[NodeFieldLayout.OBJSTRVAL_LAST_MOD_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, lastModRev);
+
+    // Field 3: payload [isCompressed:1][valueLength:varint][value:bytes]
+    heapOffsets[NodeFieldLayout.OBJSTRVAL_PAYLOAD] = (int) (pos - dataStart);
+    target.set(ValueLayout.JAVA_BYTE, pos, isCompressed ? (byte) 1 : (byte) 0);
+    pos++;
+    final byte[] valBytes = rawValue != null ? rawValue : new byte[0];
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, valBytes.length);
+    if (valBytes.length > 0) {
+      MemorySegment.copy(valBytes, 0, target, ValueLayout.JAVA_BYTE, pos, valBytes.length);
+      pos += valBytes.length;
+    }
+
+    // Write offset table
+    for (int i = 0; i < FIELD_COUNT; i++) {
+      target.set(ValueLayout.JAVA_BYTE, offsetTableStart + i, (byte) heapOffsets[i]);
+    }
+
+    return (int) (pos - offset);
+  }
+
+  /**
+   * Get the pre-allocated heap offsets array for use with static writeNewRecord.
+   */
+  public int[] getHeapOffsets() {
+    return heapOffsets;
+  }
+
+  /**
+   * Set DeweyID fields directly after creation, bypassing write-through.
+   * The DeweyID is already in the page trailer -- this just sets the Java cache fields.
+   */
+  public void setDeweyIDAfterCreation(final SirixDeweyID id, final byte[] bytes) {
+    this.sirixDeweyID = id;
+    this.deweyIDBytes = bytes;
+  }
+
+  // ==================== FLYWEIGHT BIND/UNBIND ====================
+
+  /**
+   * Bind this node as a flyweight to a page MemorySegment.
+   * When bound, getters/setters read/write directly to page memory via the offset table.
+   *
+   * @param page       the page MemorySegment
+   * @param recordBase absolute byte offset of this record in the page
+   * @param nodeKey    the node key (for delta decoding)
+   * @param slotIndex  the slot index in the page directory
+   */
+  public void bind(final MemorySegment page, final long recordBase, final long nodeKey,
+      final int slotIndex) {
+    this.page = page;
+    this.recordBase = recordBase;
+    this.nodeKey = nodeKey;
+    this.slotIndex = slotIndex;
+    this.dataRegionStart = recordBase + 1 + FIELD_COUNT;
+    this.hash = 0;
+    this.metadataParsed = true;
+    this.valueParsed = false; // Payload still needs lazy parsing from page
+    this.lazySource = null;
+  }
+
   /**
-   * Create a deep copy snapshot of this node. Forces parsing of all lazy fields since snapshot must
-   * be independent.
+   * Unbind from page memory and materialize all fields into Java primitives.
+   * After unbind, the node operates in primitive mode.
+   */
+  public void unbind() {
+    if (page == null) return;
+    final long nk = this.nodeKey;
+    this.parentKey = readDeltaField(NodeFieldLayout.OBJSTRVAL_PARENT_KEY, nk);
+    this.previousRevision = readSignedField(NodeFieldLayout.OBJSTRVAL_PREV_REVISION);
+    this.lastModifiedRevision = readSignedField(NodeFieldLayout.OBJSTRVAL_LAST_MOD_REVISION);
+    // Payload needs to be read from page before unbinding
+    if (!valueParsed) {
+      readPayloadFromPage();
+    }
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  @Override
+  public void clearBinding() {
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  /** Check if this node is bound to a page MemorySegment. */
+  public boolean isBound() { return page != null; }
+
+  @Override
+  public boolean isBoundTo(final MemorySegment page) {
+    return this.page == page;
+  }
+
+  @Override
+  public int getSlotIndex() {
+    return slotIndex;
+  }
+
+  @Override
+  public int estimateSerializedSize() {
+    final int payloadLen = value != null ? value.length : 0;
+    return 55 + payloadLen;
+  }
+
+  // ==================== FLYWEIGHT FIELD READ HELPERS ====================
+
+  private long readDeltaField(final int fieldIndex, final long baseKey) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeDeltaFromSegment(page, dataRegionStart + fieldOff, baseKey);
+  }
+
+  private int readSignedField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeSignedFromSegment(page, dataRegionStart + fieldOff);
+  }
+
+  private long readLongField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.readLongFromSegment(page, (int) (dataRegionStart + fieldOff));
+  }
+
+  // ==================== OWNER PAGE (for resize-in-place) ====================
+
+  @Override
+  public KeyValueLeafPage getOwnerPage() {
+    return ownerPage;
+  }
+
+  @Override
+  public void setOwnerPage(final KeyValueLeafPage ownerPage) {
+    this.ownerPage = ownerPage;
+  }
+
+  /**
+   * Read the payload (value bytes) directly from page memory when bound.
+   */
+  private void readPayloadFromPage() {
+    final int payloadFieldOff = page.get(ValueLayout.JAVA_BYTE,
+        recordBase + 1 + NodeFieldLayout.OBJSTRVAL_PAYLOAD) & 0xFF;
+    final long payloadStart = dataRegionStart + payloadFieldOff;
+
+    // Read isCompressed flag (1 byte)
+    this.isCompressed = page.get(ValueLayout.JAVA_BYTE, payloadStart) == 1;
+
+    // Read value length (varint)
+    final long lenOffset = payloadStart + 1;
+    final int length = DeltaVarIntCodec.decodeSignedFromSegment(page, lenOffset);
+    final int lenBytes = DeltaVarIntCodec.readSignedVarintWidth(page, lenOffset);
+
+    // Read value bytes
+    final long dataOffset = lenOffset + lenBytes;
+    this.value = new byte[length];
+    MemorySegment.copy(page, ValueLayout.JAVA_BYTE, dataOffset, this.value, 0, length);
+    this.valueParsed = true;
+  }
+
+  // ==================== SERIALIZE TO HEAP ====================
+
+  /**
+   * Serialize this node from Java fields. Delegates to static writeNewRecord.
+   *
+   * @param target the target MemorySegment
+   * @param offset the absolute byte offset to write at
+   * @return the total number of bytes written
+   */
+  public int serializeToHeap(final MemorySegment target, final long offset) {
+    if (!metadataParsed) parseMetadataFields();
+    if (!valueParsed) parseValueField();
+    return writeNewRecord(target, offset, heapOffsets, nodeKey,
+        parentKey, previousRevision, lastModifiedRevision, value, isCompressed);
+  }
+
+  /**
+   * Create a deep copy snapshot of this node.
+   * Forces parsing of all lazy fields since snapshot must be independent.
    */
   public ObjectStringNode toSnapshot() {
+    if (page != null) {
+      // Bound mode: read all fields from page
+      if (!valueParsed) {
+        readPayloadFromPage();
+      }
+      return new ObjectStringNode(nodeKey,
+          readDeltaField(NodeFieldLayout.OBJSTRVAL_PARENT_KEY, nodeKey),
+          readSignedField(NodeFieldLayout.OBJSTRVAL_PREV_REVISION),
+          readSignedField(NodeFieldLayout.OBJSTRVAL_LAST_MOD_REVISION),
+          hash,
+          value != null ? value.clone() : null,
+          hashFunction,
+          getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null,
+          isCompressed, fsstSymbolTable != null ? fsstSymbolTable.clone() : null);
+    }
     if (!metadataParsed) {
       parseMetadataFields();
     }
     if (!valueParsed) {
       parseValueField();
     }
-    return new ObjectStringNode(nodeKey, parentKey, previousRevision, lastModifiedRevision, hash, value != null
-        ? value.clone()
-        : null, hashFunction,
-        deweyIDBytes != null
-            ? deweyIDBytes.clone()
-            : null,
-        isCompressed, fsstSymbolTable != null
-            ? fsstSymbolTable.clone()
-            : null);
+    return new ObjectStringNode(nodeKey, parentKey, previousRevision, lastModifiedRevision,
+        hash, value != null ? value.clone() : null, hashFunction,
+        getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null,
+        isCompressed, fsstSymbolTable != null ? fsstSymbolTable.clone() : null);
+  }
+
+  @Override
+  public boolean isWriteSingleton() {
+    return writeSingleton;
+  }
+
+  @Override
+  public void setWriteSingleton(final boolean writeSingleton) {
+    this.writeSingleton = writeSingleton;
   }
 
   @Override
@@ -679,6 +976,8 @@ public boolean equals(final Object obj) {
     if (!(obj instanceof final ObjectStringNode other))
       return false;
 
-    return nodeKey == other.nodeKey && parentKey == other.parentKey && Objects.equal(getValue(), other.getValue());
+    return nodeKey == other.nodeKey
+        && parentKey == other.parentKey
+        && Objects.equal(getValue(), other.getValue());
   }
 }
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/json/StringNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/json/StringNode.java
index c5c85ed41..ed5673471 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/json/StringNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/json/StringNode.java
@@ -34,6 +34,7 @@
 import io.sirix.access.trx.node.HashType;
 import io.sirix.api.visitor.JsonNodeVisitor;
 import io.sirix.api.visitor.VisitResult;
+import io.sirix.node.Bytes;
 import io.sirix.node.ByteArrayBytesIn;
 import io.sirix.node.BytesIn;
 import io.sirix.node.BytesOut;
@@ -42,55 +43,54 @@
 import io.sirix.node.NodeKind;
 import io.sirix.node.SirixDeweyID;
 import io.sirix.node.immutable.json.ImmutableStringNode;
+import io.sirix.node.interfaces.FlyweightNode;
 import io.sirix.node.interfaces.Node;
-import io.sirix.node.layout.NodeKindLayout;
-import io.sirix.node.layout.SlotLayoutAccessors;
-import io.sirix.node.layout.StructuralField;
-import io.sirix.node.interfaces.ReusableNodeProxy;
 import io.sirix.node.interfaces.StructNode;
 import io.sirix.node.interfaces.ValueNode;
 import io.sirix.node.interfaces.immutable.ImmutableJsonNode;
+import io.sirix.page.KeyValueLeafPage;
+import io.sirix.page.NodeFieldLayout;
 import io.sirix.settings.Constants;
 import io.sirix.settings.Fixed;
+import io.sirix.settings.StringCompressionType;
 import io.sirix.utils.FSSTCompressor;
 import net.openhft.hashing.LongHashFunction;
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
 
 /**
  * JSON String node.
  *
- * 

- * Uses primitive fields for efficient storage with delta+varint encoding.
- * 

+ * 
Uses primitive fields for efficient storage with delta+varint encoding.

  * 
  * @author Johannes Lichtenberger
  */
-public final class StringNode implements StructNode, ValueNode, ImmutableJsonNode, ReusableNodeProxy {
+public final class StringNode implements StructNode, ValueNode, ImmutableJsonNode, FlyweightNode {
 
   // Node identity (mutable for singleton reuse)
   private long nodeKey;
-
+  
   // Mutable structural fields
   private long parentKey;
   private long rightSiblingKey;
   private long leftSiblingKey;
-
+  
   // Mutable revision tracking
   private int previousRevision;
   private int lastModifiedRevision;
-
+  
   // Mutable hash (computed on demand for value nodes)
   private long hash;
-
+  
   // String value (stored as bytes)
   private byte[] value;
-
+  
   // Hash function for computing node hashes (mutable for singleton reuse)
   private LongHashFunction hashFunction;
-
+  
   // DeweyID support (lazily parsed)
   private SirixDeweyID sirixDeweyID;
   private byte[] deweyIDBytes;
@@ -100,46 +100,67 @@ public final class StringNode implements StructNode, ValueNode, ImmutableJsonNod
   private boolean isCompressed;
   /** FSST symbol table for decompression (shared from KeyValueLeafPage) */
   private byte[] fsstSymbolTable;
-  /** Pre-parsed FSST symbol table (avoids re-parsing on every decode) */
-  private byte[][] parsedFsstSymbols;
   /** Decompressed value (lazy allocated on first access if compressed) */
   private byte[] decodedValue;
 
   // Lazy parsing state (for singleton reuse optimization)
   // Two-stage lazy parsing: metadata (cheap) vs value (expensive byte[] allocation)
-  private Object lazySource; // Source for lazy parsing (MemorySegment or byte[])
-  private long lazyOffset; // Offset where lazy metadata fields start
-  private boolean metadataParsed; // Whether prevRev, lastModRev, hash are parsed
-  private boolean valueParsed; // Whether value byte[] is parsed
-  private boolean hasHash; // Whether hash is stored (from config)
-  private long valueOffset; // Offset where value starts (after metadata)
-
-  // Fixed-slot value encoding state (for read path via populateSingletonFromFixedSlot)
-  private boolean fixedValueEncoding; // Whether value comes from fixed-slot inline payload
-  private int fixedValueLength; // Length of inline payload bytes
-  private boolean fixedValueCompressed; // Whether inline payload is FSST compressed
-
-  // Fixed-slot lazy metadata support
-  private long lazyBaseOffset;
-  private NodeKindLayout fixedSlotLayout;
+  private Object lazySource;            // Source for lazy parsing (MemorySegment or byte[])
+  private long lazyOffset;              // Offset where lazy metadata fields start
+  private boolean metadataParsed;       // Whether prevRev, lastModRev, hash are parsed
+  private boolean valueParsed;          // Whether value byte[] is parsed
+  private boolean hasHash;              // Whether hash is stored (from config)
+  private long valueOffset;             // Offset where value starts (after metadata)
+
+  // ==================== FLYWEIGHT BINDING (LeanStore page-direct access) ====================
+  private MemorySegment page;
+  private long recordBase;
+  private long dataRegionStart;
+  private int slotIndex;
+
+  /** True if this node is a factory-managed write singleton (must not be stored in records[]). */
+  private boolean writeSingleton;
+
+  /** Owning page for resize-in-place on varint width changes. */
+  private KeyValueLeafPage ownerPage;
+
+  /** Pre-allocated offset array reused across serializations (zero-alloc hot path). */
+  private final int[] heapOffsets;
+
+  private static final int FIELD_COUNT = NodeFieldLayout.STRING_VALUE_FIELD_COUNT;
+
+  /**
+   * Constructor for flyweight binding.
+   * All fields except nodeKey and hashFunction will be read from page memory after bind().
+   *
+   * @param nodeKey the node key
+   * @param hashFunction the hash function from resource config
+   */
+  public StringNode(long nodeKey, LongHashFunction hashFunction) {
+    this.nodeKey = nodeKey;
+    this.hashFunction = hashFunction;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
 
   /**
-   * Primary constructor with all primitive fields. All fields are already parsed - no lazy loading
-   * needed.
+   * Primary constructor with all primitive fields.
+   * All fields are already parsed - no lazy loading needed.
    */
-  public StringNode(long nodeKey, long parentKey, int previousRevision, int lastModifiedRevision, long rightSiblingKey,
-      long leftSiblingKey, long hash, byte[] value, LongHashFunction hashFunction, byte[] deweyID) {
-    this(nodeKey, parentKey, previousRevision, lastModifiedRevision, rightSiblingKey, leftSiblingKey, hash, value,
-        hashFunction, deweyID, false, null);
+  public StringNode(long nodeKey, long parentKey, int previousRevision,
+      int lastModifiedRevision, long rightSiblingKey, long leftSiblingKey, long hash,
+      byte[] value, LongHashFunction hashFunction, byte[] deweyID) {
+    this(nodeKey, parentKey, previousRevision, lastModifiedRevision, rightSiblingKey,
+        leftSiblingKey, hash, value, hashFunction, deweyID, false, null);
   }
 
   /**
-   * Primary constructor with all primitive fields and compression support. All fields are already
-   * parsed - no lazy loading needed.
+   * Primary constructor with all primitive fields and compression support.
+   * All fields are already parsed - no lazy loading needed.
    */
-  public StringNode(long nodeKey, long parentKey, int previousRevision, int lastModifiedRevision, long rightSiblingKey,
-      long leftSiblingKey, long hash, byte[] value, LongHashFunction hashFunction, byte[] deweyID, boolean isCompressed,
-      byte[] fsstSymbolTable) {
+  public StringNode(long nodeKey, long parentKey, int previousRevision,
+      int lastModifiedRevision, long rightSiblingKey, long leftSiblingKey, long hash,
+      byte[] value, LongHashFunction hashFunction, byte[] deweyID,
+      boolean isCompressed, byte[] fsstSymbolTable) {
     this.nodeKey = nodeKey;
     this.parentKey = parentKey;
     this.previousRevision = previousRevision;
@@ -155,24 +176,27 @@ public StringNode(long nodeKey, long parentKey, int previousRevision, int lastMo
     // Constructed with all values - mark as fully parsed
     this.metadataParsed = true;
     this.valueParsed = true;
+    this.heapOffsets = new int[FIELD_COUNT];
   }
 
   /**
-   * Constructor with SirixDeweyID instead of byte array. All fields are already parsed - no lazy
-   * loading needed.
+   * Constructor with SirixDeweyID instead of byte array.
+   * All fields are already parsed - no lazy loading needed.
    */
-  public StringNode(long nodeKey, long parentKey, int previousRevision, int lastModifiedRevision, long rightSiblingKey,
-      long leftSiblingKey, long hash, byte[] value, LongHashFunction hashFunction, SirixDeweyID deweyID) {
-    this(nodeKey, parentKey, previousRevision, lastModifiedRevision, rightSiblingKey, leftSiblingKey, hash, value,
-        hashFunction, deweyID, false, null);
+  public StringNode(long nodeKey, long parentKey, int previousRevision,
+      int lastModifiedRevision, long rightSiblingKey, long leftSiblingKey, long hash,
+      byte[] value, LongHashFunction hashFunction, SirixDeweyID deweyID) {
+    this(nodeKey, parentKey, previousRevision, lastModifiedRevision, rightSiblingKey,
+        leftSiblingKey, hash, value, hashFunction, deweyID, false, null);
   }
 
   /**
-   * Constructor with SirixDeweyID and compression support. All fields are already parsed - no lazy
-   * loading needed.
+   * Constructor with SirixDeweyID and compression support.
+   * All fields are already parsed - no lazy loading needed.
    */
-  public StringNode(long nodeKey, long parentKey, int previousRevision, int lastModifiedRevision, long rightSiblingKey,
-      long leftSiblingKey, long hash, byte[] value, LongHashFunction hashFunction, SirixDeweyID deweyID,
+  public StringNode(long nodeKey, long parentKey, int previousRevision,
+      int lastModifiedRevision, long rightSiblingKey, long leftSiblingKey, long hash,
+      byte[] value, LongHashFunction hashFunction, SirixDeweyID deweyID,
       boolean isCompressed, byte[] fsstSymbolTable) {
     this.nodeKey = nodeKey;
     this.parentKey = parentKey;
@@ -189,6 +213,211 @@ public StringNode(long nodeKey, long parentKey, int previousRevision, int lastMo
     // Constructed with all values - mark as fully parsed
     this.metadataParsed = true;
     this.valueParsed = true;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
+
+  // ==================== FLYWEIGHT BIND/UNBIND ====================
+
+  public void bind(final MemorySegment page, final long recordBase, final long nodeKey,
+      final int slotIndex) {
+    this.page = page;
+    this.recordBase = recordBase;
+    this.nodeKey = nodeKey;
+    this.slotIndex = slotIndex;
+    this.dataRegionStart = recordBase + 1 + FIELD_COUNT;
+    this.hash = 0;
+    this.metadataParsed = true;
+    this.valueParsed = false; // Payload still needs lazy parsing from page
+    this.lazySource = null;
+  }
+
+  public void unbind() {
+    if (page == null) return;
+    final long nk = this.nodeKey;
+    this.parentKey = readDeltaField(NodeFieldLayout.STRVAL_PARENT_KEY, nk);
+    this.rightSiblingKey = readDeltaField(NodeFieldLayout.STRVAL_RIGHT_SIB_KEY, nk);
+    this.leftSiblingKey = readDeltaField(NodeFieldLayout.STRVAL_LEFT_SIB_KEY, nk);
+    this.previousRevision = readSignedField(NodeFieldLayout.STRVAL_PREV_REVISION);
+    this.lastModifiedRevision = readSignedField(NodeFieldLayout.STRVAL_LAST_MOD_REVISION);
+    // Payload needs to be read from page before unbinding
+    if (!valueParsed) {
+      readPayloadFromPage();
+    }
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  @Override
+  public void clearBinding() {
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  public boolean isBound() { return page != null; }
+
+  @Override
+  public boolean isBoundTo(final MemorySegment page) {
+    return this.page == page;
+  }
+
+  @Override
+  public int getSlotIndex() {
+    return slotIndex;
+  }
+
+  @Override
+  public int estimateSerializedSize() {
+    final int payloadLen = value != null ? value.length : 0;
+    return 55 + payloadLen;
+  }
+
+  // ==================== FLYWEIGHT FIELD READ HELPERS ====================
+
+  private long readDeltaField(final int fieldIndex, final long baseKey) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeDeltaFromSegment(page, dataRegionStart + fieldOff, baseKey);
+  }
+
+  private int readSignedField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeSignedFromSegment(page, dataRegionStart + fieldOff);
+  }
+
+
+  @Override
+  public KeyValueLeafPage getOwnerPage() {
+    return ownerPage;
+  }
+
+  @Override
+  public void setOwnerPage(final KeyValueLeafPage ownerPage) {
+    this.ownerPage = ownerPage;
+  }
+
+  /**
+   * Read the payload (value bytes) directly from page memory when bound.
+   */
+  private void readPayloadFromPage() {
+    final int payloadFieldOff = page.get(ValueLayout.JAVA_BYTE,
+        recordBase + 1 + NodeFieldLayout.STRVAL_PAYLOAD) & 0xFF;
+    final long payloadStart = dataRegionStart + payloadFieldOff;
+
+    // Read isCompressed flag (1 byte)
+    this.isCompressed = page.get(ValueLayout.JAVA_BYTE, payloadStart) == 1;
+
+    // Read value length (varint)
+    final long lenOffset = payloadStart + 1;
+    final int length = DeltaVarIntCodec.decodeSignedFromSegment(page, lenOffset);
+    final int lenBytes = DeltaVarIntCodec.readSignedVarintWidth(page, lenOffset);
+
+    // Read value bytes
+    final long dataOffset = lenOffset + lenBytes;
+    this.value = new byte[length];
+    MemorySegment.copy(page, ValueLayout.JAVA_BYTE, dataOffset, this.value, 0, length);
+    this.valueParsed = true;
+  }
+
+  // ==================== SERIALIZE TO HEAP ====================
+
+  /**
+   * Encode a StringNode record directly to a MemorySegment from parameter values.
+   * Static -- reads nothing from any instance. Zero field intermediation.
+   *
+   * @param target        the target MemorySegment (reinterpreted slotted page)
+   * @param offset        absolute byte offset to write at
+   * @param heapOffsets   pre-allocated offset array (reused, FIELD_COUNT elements)
+   * @param nodeKey       the node key (delta base for structural keys)
+   * @param parentKey     the parent node key
+   * @param rightSibKey   the right sibling key
+   * @param leftSibKey    the left sibling key
+   * @param prevRev       the previous revision number
+   * @param lastModRev    the last modified revision number
+   * @param rawValue      the raw value bytes (possibly compressed)
+   * @param isCompressed  whether the value is FSST compressed
+   * @return the total number of bytes written
+   */
+  public static int writeNewRecord(final MemorySegment target, final long offset,
+      final int[] heapOffsets, final long nodeKey,
+      final long parentKey, final long rightSibKey, final long leftSibKey,
+      final int prevRev, final int lastModRev,
+      final byte[] rawValue, final boolean isCompressed) {
+    long pos = offset;
+
+    // Write nodeKind byte
+    target.set(ValueLayout.JAVA_BYTE, pos, NodeKind.STRING_VALUE.getId());
+    pos++;
+
+    // Reserve space for offset table
+    final long offsetTableStart = pos;
+    pos += FIELD_COUNT;
+
+    // Data region start
+    final long dataStart = pos;
+
+    // Field 0: parentKey (delta-varint)
+    heapOffsets[NodeFieldLayout.STRVAL_PARENT_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, parentKey, nodeKey);
+
+    // Field 1: rightSiblingKey (delta-varint)
+    heapOffsets[NodeFieldLayout.STRVAL_RIGHT_SIB_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, rightSibKey, nodeKey);
+
+    // Field 2: leftSiblingKey (delta-varint)
+    heapOffsets[NodeFieldLayout.STRVAL_LEFT_SIB_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, leftSibKey, nodeKey);
+
+    // Field 3: previousRevision (signed varint)
+    heapOffsets[NodeFieldLayout.STRVAL_PREV_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, prevRev);
+
+    // Field 4: lastModifiedRevision (signed varint)
+    heapOffsets[NodeFieldLayout.STRVAL_LAST_MOD_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, lastModRev);
+
+    // Field 5: payload [isCompressed:1][valueLength:varint][value:bytes]
+    heapOffsets[NodeFieldLayout.STRVAL_PAYLOAD] = (int) (pos - dataStart);
+    target.set(ValueLayout.JAVA_BYTE, pos, isCompressed ? (byte) 1 : (byte) 0);
+    pos++;
+    final byte[] val = rawValue != null ? rawValue : new byte[0];
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, val.length);
+    if (val.length > 0) {
+      MemorySegment.copy(val, 0, target, ValueLayout.JAVA_BYTE, pos, val.length);
+      pos += val.length;
+    }
+
+    // Write offset table
+    for (int i = 0; i < FIELD_COUNT; i++) {
+      target.set(ValueLayout.JAVA_BYTE, offsetTableStart + i, (byte) heapOffsets[i]);
+    }
+
+    return (int) (pos - offset);
+  }
+
+  /**
+   * Serialize this node from Java fields. Delegates to static writeNewRecord.
+   */
+  public int serializeToHeap(final MemorySegment target, final long offset) {
+    if (!metadataParsed) parseMetadataFields();
+    if (!valueParsed) parseValueField();
+    return writeNewRecord(target, offset, heapOffsets, nodeKey,
+        parentKey, rightSiblingKey, leftSiblingKey,
+        previousRevision, lastModifiedRevision, value, isCompressed);
+  }
+
+  /**
+   * Get the pre-allocated heap offsets array for use with static writeNewRecord.
+   */
+  public int[] getHeapOffsets() {
+    return heapOffsets;
+  }
+
+  /**
+   * Set DeweyID fields directly after creation, bypassing write-through.
+   * The DeweyID is already in the page trailer -- this just sets the Java cache fields.
+   */
+  public void setDeweyIDAfterCreation(final SirixDeweyID id, final byte[] bytes) {
+    this.sirixDeweyID = id;
+    this.deweyIDBytes = bytes;
   }
 
   @Override
@@ -203,16 +432,38 @@ public long getNodeKey() {
 
   @Override
   public long getParentKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.STRVAL_PARENT_KEY, nodeKey);
+    }
     return parentKey;
   }
 
   public void setParentKey(final long parentKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.STRVAL_PARENT_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(parentKey, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, parentKey, nodeKey);
+        return;
+      }
+      resizeParentKey(parentKey);
+      return;
+    }
     this.parentKey = parentKey;
   }
 
+  private void resizeParentKey(final long parentKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.STRVAL_PARENT_KEY, NodeFieldLayout.STRING_VALUE_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, parentKey, nodeKey));
+  }
+
   @Override
   public boolean hasParent() {
-    return parentKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getParentKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
@@ -227,26 +478,83 @@ public void setTypeKey(final int typeKey) {
 
   @Override
   public void setDeweyID(final SirixDeweyID id) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.sirixDeweyID = id;
+      this.deweyIDBytes = null;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
     this.sirixDeweyID = id;
     this.deweyIDBytes = null;
   }
 
+  @Override
+  public void setDeweyIDBytes(final byte[] bytes) {
+    this.deweyIDBytes = bytes;
+    this.sirixDeweyID = null;
+  }
+
   @Override
   public void setPreviousRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.STRVAL_PREV_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizePreviousRevision(revision);
+      return;
+    }
     this.previousRevision = revision;
   }
 
+  private void resizePreviousRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.STRVAL_PREV_REVISION, NodeFieldLayout.STRING_VALUE_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+  }
+
   @Override
   public void setLastModifiedRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.STRVAL_LAST_MOD_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizeLastModifiedRevision(revision);
+      return;
+    }
     this.lastModifiedRevision = revision;
   }
 
+  private void resizeLastModifiedRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.STRVAL_LAST_MOD_REVISION, NodeFieldLayout.STRING_VALUE_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+  }
+
   @Override
   public long getHash() {
-    if (!metadataParsed) {
-      parseMetadataFields();
+    if (hash != 0L) {
+      return hash;
     }
-    return hash;
+    if (hashFunction != null) {
+      return computeHash(Bytes.threadLocalHashBuffer());
+    }
+    return 0L;
   }
 
   @Override
@@ -257,38 +565,85 @@ public void setHash(final long hash) {
   @Override
   public long computeHash(final BytesOut bytes) {
     bytes.clear();
-    bytes.writeLong(getNodeKey()).writeLong(getParentKey()).writeByte(getKind().getId());
-
-    bytes.writeLong(getLeftSiblingKey()).writeLong(getRightSiblingKey());
+    bytes.writeLong(getNodeKey())
+         .writeLong(getParentKey())
+         .writeByte(getKind().getId());
 
-    bytes.writeUtf8(getValue());
+    final byte[] rawValue = getRawValue();
+    if (rawValue != null) {
+      bytes.write(rawValue);
+    }
 
     return bytes.hashDirect(hashFunction);
   }
 
   @Override
   public long getRightSiblingKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.STRVAL_RIGHT_SIB_KEY, nodeKey);
+    }
     return rightSiblingKey;
   }
 
   public void setRightSiblingKey(final long rightSibling) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.STRVAL_RIGHT_SIB_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(rightSibling, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, rightSibling, nodeKey);
+        return;
+      }
+      resizeRightSiblingKey(rightSibling);
+      return;
+    }
     this.rightSiblingKey = rightSibling;
   }
 
+  private void resizeRightSiblingKey(final long rightSibling) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.STRVAL_RIGHT_SIB_KEY, NodeFieldLayout.STRING_VALUE_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, rightSibling, nodeKey));
+  }
+
   @Override
   public long getLeftSiblingKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.STRVAL_LEFT_SIB_KEY, nodeKey);
+    }
     return leftSiblingKey;
   }
 
   public void setLeftSiblingKey(final long leftSibling) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.STRVAL_LEFT_SIB_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(leftSibling, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, leftSibling, nodeKey);
+        return;
+      }
+      resizeLeftSiblingKey(leftSibling);
+      return;
+    }
     this.leftSiblingKey = leftSibling;
   }
 
+  private void resizeLeftSiblingKey(final long leftSibling) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.STRVAL_LEFT_SIB_KEY, NodeFieldLayout.STRING_VALUE_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, leftSibling, nodeKey));
+  }
+
   @Override
   public long getFirstChildKey() {
     return Fixed.NULL_NODE_KEY.getStandardProperty();
   }
-
+  
   public void setFirstChildKey(final long firstChild) {
     // Value nodes are leaf nodes - no-op
   }
@@ -297,7 +652,7 @@ public void setFirstChildKey(final long firstChild) {
   public long getLastChildKey() {
     return Fixed.NULL_NODE_KEY.getStandardProperty();
   }
-
+  
   public void setLastChildKey(final long lastChild) {
     // Value nodes are leaf nodes - no-op
   }
@@ -306,7 +661,7 @@ public void setLastChildKey(final long lastChild) {
   public long getChildCount() {
     return 0;
   }
-
+  
   public void setChildCount(final long childCount) {
     // Value nodes are leaf nodes - no-op
   }
@@ -315,34 +670,35 @@ public void setChildCount(final long childCount) {
   public long getDescendantCount() {
     return 0;
   }
-
+  
   public void setDescendantCount(final long descendantCount) {
     // Value nodes are leaf nodes - no-op
   }
 
   @Override
   public byte[] getRawValue() {
-    if (!valueParsed) {
+    if (page != null && !valueParsed) {
+      readPayloadFromPage();
+    } else if (!valueParsed) {
       parseValueField();
     }
-    // If compressed, decode on first access using pre-parsed symbols when available
+    // If compressed, decode on first access
     if (isCompressed && decodedValue == null && value != null) {
-      final byte[][] parsed = parsedFsstSymbols;
-      decodedValue = (parsed != null) ? FSSTCompressor.decode(value, parsed) : FSSTCompressor.decode(value, fsstSymbolTable);
+      decodedValue = FSSTCompressor.decode(value, fsstSymbolTable);
     }
-    return isCompressed
-        ? decodedValue
-        : value;
+    return isCompressed ? decodedValue : value;
   }
 
   /**
-   * Get the raw (possibly compressed) value bytes without FSST decoding. Use this for serialization
-   * to preserve compression.
+   * Get the raw (possibly compressed) value bytes without FSST decoding.
+   * Use this for serialization to preserve compression.
    * 
    * @return the raw bytes as stored, possibly FSST compressed
    */
   public byte[] getRawValueWithoutDecompression() {
-    if (!valueParsed) {
+    if (page != null && !valueParsed) {
+      readPayloadFromPage();
+    } else if (!valueParsed) {
       parseValueField();
     }
     return value;
@@ -350,10 +706,19 @@ public byte[] getRawValueWithoutDecompression() {
 
   @Override
   public void setRawValue(final byte[] value) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.value = value;
+      this.decodedValue = null;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
+    if (page != null) unbind();
     this.value = value;
     this.decodedValue = null;
-    this.fixedValueEncoding = false;
-    this.valueParsed = true;
   }
 
   /**
@@ -364,12 +729,23 @@ public void setRawValue(final byte[] value) {
    * @param fsstSymbolTable the symbol table for decompression (or null if not compressed)
    */
   public void setRawValue(final byte[] value, boolean isCompressed, byte[] fsstSymbolTable) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.value = value;
+      this.isCompressed = isCompressed;
+      this.fsstSymbolTable = fsstSymbolTable;
+      this.decodedValue = null;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
+    if (page != null) unbind();
     this.value = value;
     this.isCompressed = isCompressed;
     this.fsstSymbolTable = fsstSymbolTable;
     this.decodedValue = null;
-    this.fixedValueEncoding = false;
-    this.valueParsed = true;
   }
 
   /**
@@ -378,12 +754,15 @@ public void setRawValue(final byte[] value, boolean isCompressed, byte[] fsstSym
    * @return true if compressed
    */
   public boolean isCompressed() {
+    if (page != null && !valueParsed) {
+      readPayloadFromPage();
+    }
     return isCompressed;
   }
 
   /**
    * Set compression state.
-   * 
+   *
    * @param isCompressed true if value is compressed
    */
   public void setCompressed(boolean isCompressed) {
@@ -401,27 +780,14 @@ public byte[] getFsstSymbolTable() {
 
   /**
    * Set the FSST symbol table.
-   *
+   * 
    * @param fsstSymbolTable the symbol table
    */
   public void setFsstSymbolTable(byte[] fsstSymbolTable) {
     this.fsstSymbolTable = fsstSymbolTable;
-    this.parsedFsstSymbols = null;
     this.decodedValue = null; // Reset decoded value when table changes
   }
 
-  /**
-   * Set the FSST symbol table with pre-parsed symbols to avoid redundant parsing.
-   *
-   * @param fsstSymbolTable the raw symbol table bytes
-   * @param parsedFsstSymbols the pre-parsed symbol arrays
-   */
-  public void setFsstSymbolTable(byte[] fsstSymbolTable, byte[][] parsedFsstSymbols) {
-    this.fsstSymbolTable = fsstSymbolTable;
-    this.parsedFsstSymbols = parsedFsstSymbols;
-    this.decodedValue = null;
-  }
-
   @Override
   public String getValue() {
     // Use getRawValue() which handles FSST decompression
@@ -461,16 +827,19 @@ public void decrementDescendantCount() {
 
   @Override
   public boolean hasLeftSibling() {
-    return leftSiblingKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getLeftSiblingKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public boolean hasRightSibling() {
-    return rightSiblingKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getRightSiblingKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public int getPreviousRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.STRVAL_PREV_REVISION);
+    }
     if (!metadataParsed) {
       parseMetadataFields();
     }
@@ -479,6 +848,9 @@ public int getPreviousRevisionNumber() {
 
   @Override
   public int getLastModifiedRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.STRVAL_LAST_MOD_REVISION);
+    }
     if (!metadataParsed) {
       parseMetadataFields();
     }
@@ -494,18 +866,15 @@ public void setNodeKey(final long nodeKey) {
     this.nodeKey = nodeKey;
   }
 
-  public void setDeweyIDBytes(final byte[] deweyIDBytes) {
-    this.deweyIDBytes = deweyIDBytes;
-    this.sirixDeweyID = null;
-  }
-
   /**
-   * Populate this node from a BytesIn source for singleton reuse. LAZY OPTIMIZATION: Only parses
-   * structural fields immediately. Two-stage lazy parsing: metadata (cheap) vs value (expensive
-   * byte[] allocation).
+   * Populate this node from a BytesIn source for singleton reuse.
+   * LAZY OPTIMIZATION: Only parses structural fields immediately.
+   * Two-stage lazy parsing: metadata (cheap) vs value (expensive byte[] allocation).
    */
   public void readFrom(final BytesIn source, final long nodeKey, final byte[] deweyId,
-      final LongHashFunction hashFunction, final ResourceConfiguration config) {
+                       final LongHashFunction hashFunction, final ResourceConfiguration config) {
+    // Unbind flyweight — ensures getters use Java fields, not stale page reference
+    this.page = null;
     this.nodeKey = nodeKey;
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyId;
@@ -523,126 +892,71 @@ public void readFrom(final BytesIn source, final long nodeKey, final byte[] d
     this.valueParsed = false;
     this.hasHash = config.hashType != HashType.NONE;
     this.valueOffset = 0;
-
+    
     // Initialize lazy fields to defaults (will be populated on demand)
     this.previousRevision = 0;
     this.lastModifiedRevision = 0;
     this.hash = 0;
     this.value = null;
   }
-
-  /**
-   * Populate this singleton from fixed-slot inline payload (zero allocation). Sets up lazy value
-   * parsing from the fixed-slot MemorySegment. CRITICAL: Resets hash to 0 — caller MUST call
-   * setHash() AFTER this method.
-   *
-   * @param source the slot data (MemorySegment) containing inline payload
-   * @param valueOffset byte offset within source where payload bytes start
-   * @param valueLength length of payload bytes
-   * @param compressed whether the payload is FSST compressed
-   */
-  public void setLazyRawValue(final Object source, final long valueOffset, final int valueLength,
-      final boolean compressed) {
-    this.lazySource = source;
-    this.valueOffset = valueOffset;
-    this.metadataParsed = true;
-    this.valueParsed = false;
-    this.fixedValueEncoding = true;
-    this.fixedValueLength = valueLength;
-    this.fixedValueCompressed = compressed;
-    this.value = null;
-    this.fsstSymbolTable = null;
-    this.parsedFsstSymbols = null;
-    this.decodedValue = null;
-    this.hash = 0L;
-  }
-
-  public void bindFixedSlotLazy(final MemorySegment slotData, final long baseOffset, final NodeKindLayout layout) {
-    this.lazyBaseOffset = baseOffset;
-    this.fixedSlotLayout = layout;
-    this.metadataParsed = false;
-  }
-
+  
   /**
-   * Parse metadata fields on demand (cheap - just varints and optionally a long). Called by getters
-   * that access prevRev, lastModRev, or hash.
+   * Parse metadata fields on demand (cheap - just varints and optionally a long).
+   * Called by getters that access prevRev, lastModRev, or hash.
    */
   private void parseMetadataFields() {
     if (metadataParsed) {
       return;
     }
-
-    if (fixedSlotLayout != null) {
-      final MemorySegment sd = (MemorySegment) lazySource;
-      final NodeKindLayout ly = fixedSlotLayout;
-      final long off = this.lazyBaseOffset;
-      this.previousRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.PREVIOUS_REVISION);
-      this.lastModifiedRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.LAST_MODIFIED_REVISION);
-      this.hash = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.HASH);
-      this.fixedSlotLayout = null;
-      this.metadataParsed = true;
-      return;
-    }
-
+    
     if (lazySource == null) {
+      // Already fully constructed (e.g., from constructor)
       metadataParsed = true;
       return;
     }
-
+    
     BytesIn bytesIn = createBytesIn(lazyOffset);
-
+    
     this.previousRevision = DeltaVarIntCodec.decodeSigned(bytesIn);
     this.lastModifiedRevision = DeltaVarIntCodec.decodeSigned(bytesIn);
     if (hasHash) {
-      this.hash = bytesIn.readLong();
+      bytesIn.readLong(); // skip legacy hash field
     }
     // Store position where value starts (for separate value parsing)
     this.valueOffset = bytesIn.position();
     this.metadataParsed = true;
   }
-
+  
   /**
-   * Parse value field on demand (expensive - allocates byte[]). Called by getValue() and
-   * getRawValue().
+   * Parse value field on demand (expensive - allocates byte[]).
+   * Called by getValue() and getRawValue().
    */
   private void parseValueField() {
     if (valueParsed) {
       return;
     }
-
-    // Fixed-slot inline payload path (from setLazyRawValue)
-    if (fixedValueEncoding) {
-      final BytesIn bytesIn = createBytesIn(valueOffset);
-      this.isCompressed = fixedValueCompressed;
-      this.value = new byte[fixedValueLength];
-      if (fixedValueLength > 0) {
-        bytesIn.read(this.value, 0, fixedValueLength);
-      }
-      this.valueParsed = true;
-      return;
-    }
-
+    
     // Must parse metadata first to know where value starts
     if (!metadataParsed) {
       parseMetadataFields();
     }
-
+    
     if (lazySource == null) {
       valueParsed = true;
       return;
     }
-
-    final BytesIn bytesIn = createBytesIn(valueOffset);
-
+    
+    BytesIn bytesIn = createBytesIn(valueOffset);
+    
     // Read compression flag (1 byte: 0 = none, 1 = FSST)
     this.isCompressed = bytesIn.readByte() == 1;
-
-    final int length = DeltaVarIntCodec.decodeSigned(bytesIn);
+    
+    int length = DeltaVarIntCodec.decodeSigned(bytesIn);
     this.value = new byte[length];
     bytesIn.read(this.value);
     this.valueParsed = true;
   }
-
+  
   /**
    * Create a BytesIn for reading from the lazy source at the given offset.
    */
@@ -661,10 +975,27 @@ private BytesIn createBytesIn(long offset) {
   }
 
   /**
-   * Create a deep copy snapshot of this node. Forces parsing of all lazy fields since snapshot must
-   * be independent.
+   * Create a deep copy snapshot of this node.
+   * Forces parsing of all lazy fields since snapshot must be independent.
    */
   public StringNode toSnapshot() {
+    if (page != null) {
+      // Bound mode: read all fields from page
+      if (!valueParsed) {
+        readPayloadFromPage();
+      }
+      return new StringNode(nodeKey,
+          readDeltaField(NodeFieldLayout.STRVAL_PARENT_KEY, nodeKey),
+          readSignedField(NodeFieldLayout.STRVAL_PREV_REVISION),
+          readSignedField(NodeFieldLayout.STRVAL_LAST_MOD_REVISION),
+          readDeltaField(NodeFieldLayout.STRVAL_RIGHT_SIB_KEY, nodeKey),
+          readDeltaField(NodeFieldLayout.STRVAL_LEFT_SIB_KEY, nodeKey),
+          hash,
+          value != null ? value.clone() : null,
+          hashFunction,
+          getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null,
+          isCompressed, fsstSymbolTable != null ? fsstSymbolTable.clone() : null);
+    }
     // Force parse all lazy fields for snapshot (must be complete and independent)
     if (!metadataParsed) {
       parseMetadataFields();
@@ -672,16 +1003,22 @@ public StringNode toSnapshot() {
     if (!valueParsed) {
       parseValueField();
     }
-    return new StringNode(nodeKey, parentKey, previousRevision, lastModifiedRevision, rightSiblingKey, leftSiblingKey,
-        hash, value != null
-            ? value.clone()
-            : null,
-        hashFunction, deweyIDBytes != null
-            ? deweyIDBytes.clone()
-            : null,
-        isCompressed, fsstSymbolTable != null
-            ? fsstSymbolTable.clone()
-            : null);
+    return new StringNode(nodeKey, parentKey, previousRevision, lastModifiedRevision,
+        rightSiblingKey, leftSiblingKey, hash,
+        value != null ? value.clone() : null,
+        hashFunction,
+        getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null,
+        isCompressed, fsstSymbolTable != null ? fsstSymbolTable.clone() : null);
+  }
+
+  @Override
+  public boolean isWriteSingleton() {
+    return writeSingleton;
+  }
+
+  @Override
+  public void setWriteSingleton(final boolean writeSingleton) {
+    this.writeSingleton = writeSingleton;
   }
 
   @Override
@@ -728,6 +1065,8 @@ public boolean equals(final Object obj) {
     if (!(obj instanceof final StringNode other))
       return false;
 
-    return nodeKey == other.nodeKey && parentKey == other.parentKey && Objects.equal(getValue(), other.getValue());
+    return nodeKey == other.nodeKey
+        && parentKey == other.parentKey
+        && Objects.equal(getValue(), other.getValue());
   }
 }
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/layout/CompactFieldCodec.java b/bundles/sirix-core/src/main/java/io/sirix/node/layout/CompactFieldCodec.java
deleted file mode 100644
index 454bb31d0..000000000
--- a/bundles/sirix-core/src/main/java/io/sirix/node/layout/CompactFieldCodec.java
+++ /dev/null
@@ -1,61 +0,0 @@
-package io.sirix.node.layout;
-
-import io.sirix.node.BytesIn;
-import io.sirix.node.BytesOut;
-import io.sirix.node.DeltaVarIntCodec;
-
-import java.util.Objects;
-
-/**
- * Shared codec primitives used by compact commit encoders.
- */
-public final class CompactFieldCodec {
-  private CompactFieldCodec() {}
-
-  public static void encodeNodeKeyDelta(final BytesOut sink, final long baseNodeKey, final long targetNodeKey) {
-    DeltaVarIntCodec.encodeDelta(Objects.requireNonNull(sink), targetNodeKey, baseNodeKey);
-  }
-
-  public static long decodeNodeKeyDelta(final BytesIn source, final long baseNodeKey) {
-    return DeltaVarIntCodec.decodeDelta(Objects.requireNonNull(source), baseNodeKey);
-  }
-
-  public static void encodeSignedInt(final BytesOut sink, final int value) {
-    DeltaVarIntCodec.encodeSigned(Objects.requireNonNull(sink), value);
-  }
-
-  public static int decodeSignedInt(final BytesIn source) {
-    return DeltaVarIntCodec.decodeSigned(Objects.requireNonNull(source));
-  }
-
-  public static void encodeSignedLong(final BytesOut sink, final long value) {
-    DeltaVarIntCodec.encodeSignedLong(Objects.requireNonNull(sink), value);
-  }
-
-  public static long decodeSignedLong(final BytesIn source) {
-    return DeltaVarIntCodec.decodeSignedLong(Objects.requireNonNull(source));
-  }
-
-  public static void encodeNonNegativeInt(final BytesOut sink, final int value) {
-    if (value < 0) {
-      throw new IllegalArgumentException("value must be >= 0");
-    }
-    encodeSignedInt(sink, value);
-  }
-
-  public static int decodeNonNegativeInt(final BytesIn source, final String fieldName) {
-    final int value = decodeSignedInt(source);
-    if (value < 0) {
-      throw new IllegalStateException("Decoded negative value for " + Objects.requireNonNull(fieldName) + ": " + value);
-    }
-    return value;
-  }
-
-  public static int decodeNonNegativeInt(final BytesIn source) {
-    final int value = decodeSignedInt(source);
-    if (value < 0) {
-      throw new IllegalStateException("Decoded negative value: " + value);
-    }
-    return value;
-  }
-}
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/layout/CompactPageEncoder.java b/bundles/sirix-core/src/main/java/io/sirix/node/layout/CompactPageEncoder.java
deleted file mode 100644
index 22df5dcc4..000000000
--- a/bundles/sirix-core/src/main/java/io/sirix/node/layout/CompactPageEncoder.java
+++ /dev/null
@@ -1,214 +0,0 @@
-package io.sirix.node.layout;
-
-import io.sirix.node.BytesIn;
-import io.sirix.node.BytesOut;
-import io.sirix.node.NodeKind;
-
-import java.util.Objects;
-
-/**
- * Lightweight V1 page-level compact encoding helpers.
- *
- * 

- * The methods here are intentionally allocation-minimal and operate directly on primitive vectors.
- */
-public final class CompactPageEncoder {
-  private static final int MAX_RELATIONSHIP_VECTOR_LENGTH = 1 << 20;
-
-  private CompactPageEncoder() {}
-
-  public static void encodeSlotHeader(final BytesOut sink, final SlotHeader slotHeader) {
-    Objects.requireNonNull(slotHeader, "slotHeader must not be null");
-    CompactFieldCodec.encodeSignedLong(sink, slotHeader.nodeKey());
-    sink.writeByte(slotHeader.nodeKind().getId());
-    CompactFieldCodec.encodeNonNegativeInt(sink, slotHeader.fixedSlotSizeInBytes());
-    CompactFieldCodec.encodeNonNegativeInt(sink, slotHeader.payloadSizeInBytes());
-  }
-
-  public static SlotHeader decodeSlotHeader(final BytesIn source) {
-    final MutableSlotHeader header = new MutableSlotHeader();
-    decodeSlotHeader(source, header);
-    return new SlotHeader(header.nodeKey(), header.nodeKind(), header.fixedSlotSizeInBytes(),
-        header.payloadSizeInBytes());
-  }
-
-  /**
-   * Decode a slot header into a caller-owned reusable object to avoid allocations.
-   */
-  public static void decodeSlotHeader(final BytesIn source, final MutableSlotHeader target) {
-    Objects.requireNonNull(source, "source must not be null");
-    Objects.requireNonNull(target, "target must not be null");
-
-    final long nodeKey = CompactFieldCodec.decodeSignedLong(source);
-
-    final byte kindId = source.readByte();
-    if (kindId < 0) {
-      throw new IllegalStateException("Invalid negative node kind id: " + kindId);
-    }
-
-    final NodeKind nodeKind = NodeKind.getKind(kindId);
-    if (nodeKind == null) {
-      throw new IllegalStateException("Unknown node kind id: " + kindId);
-    }
-
-    final int fixedSlotSizeInBytes = CompactFieldCodec.decodeNonNegativeInt(source);
-    final int payloadSizeInBytes = CompactFieldCodec.decodeNonNegativeInt(source);
-    target.set(nodeKey, nodeKind, fixedSlotSizeInBytes, payloadSizeInBytes);
-  }
-
-  public static void encodeRelationshipVector(final BytesOut sink, final long baseNodeKey,
-      final long[] relationshipNodeKeys) {
-    Objects.requireNonNull(relationshipNodeKeys, "relationshipNodeKeys must not be null");
-    CompactFieldCodec.encodeNonNegativeInt(sink, relationshipNodeKeys.length);
-    for (final long relationshipNodeKey : relationshipNodeKeys) {
-      CompactFieldCodec.encodeNodeKeyDelta(sink, baseNodeKey, relationshipNodeKey);
-    }
-  }
-
-  public static long[] decodeRelationshipVector(final BytesIn source, final long baseNodeKey) {
-    final int length = CompactFieldCodec.decodeNonNegativeInt(source);
-    if (length > MAX_RELATIONSHIP_VECTOR_LENGTH) {
-      throw new IllegalStateException("Relationship vector length exceeds limit: " + length);
-    }
-
-    final long[] relationshipNodeKeys = new long[length];
-    for (int i = 0; i < length; i++) {
-      relationshipNodeKeys[i] = CompactFieldCodec.decodeNodeKeyDelta(source, baseNodeKey);
-    }
-    return relationshipNodeKeys;
-  }
-
-  /**
-   * Decode a relationship vector into a caller-owned reusable buffer.
-   *
-   * @return number of decoded entries written into {@code targetBuffer}
-   */
-  public static int decodeRelationshipVector(final BytesIn source, final long baseNodeKey,
-      final long[] targetBuffer) {
-    Objects.requireNonNull(targetBuffer, "targetBuffer must not be null");
-    final int length = CompactFieldCodec.decodeNonNegativeInt(source);
-    if (length > MAX_RELATIONSHIP_VECTOR_LENGTH) {
-      throw new IllegalStateException("Relationship vector length exceeds limit: " + length);
-    }
-    if (length > targetBuffer.length) {
-      throw new IllegalArgumentException(
-          "Target buffer too small. length=" + length + ", capacity=" + targetBuffer.length);
-    }
-
-    for (int i = 0; i < length; i++) {
-      targetBuffer[i] = CompactFieldCodec.decodeNodeKeyDelta(source, baseNodeKey);
-    }
-    return length;
-  }
-
-  public static void encodePayloadBlockHeader(final BytesOut sink, final PayloadBlockHeader payloadBlockHeader) {
-    Objects.requireNonNull(payloadBlockHeader, "payloadBlockHeader must not be null");
-    CompactFieldCodec.encodeSignedLong(sink, payloadBlockHeader.payloadPointer());
-    CompactFieldCodec.encodeNonNegativeInt(sink, payloadBlockHeader.payloadLengthInBytes());
-    CompactFieldCodec.encodeNonNegativeInt(sink, payloadBlockHeader.payloadFlags());
-  }
-
-  public static PayloadBlockHeader decodePayloadBlockHeader(final BytesIn source) {
-    final MutablePayloadBlockHeader payloadBlockHeader = new MutablePayloadBlockHeader();
-    decodePayloadBlockHeader(source, payloadBlockHeader);
-    return new PayloadBlockHeader(payloadBlockHeader.payloadPointer(), payloadBlockHeader.payloadLengthInBytes(),
-        payloadBlockHeader.payloadFlags());
-  }
-
-  /**
-   * Decode a payload block header into a caller-owned reusable object to avoid allocations.
-   */
-  public static void decodePayloadBlockHeader(final BytesIn source, final MutablePayloadBlockHeader target) {
-    Objects.requireNonNull(source, "source must not be null");
-    Objects.requireNonNull(target, "target must not be null");
-
-    final long payloadPointer = CompactFieldCodec.decodeSignedLong(source);
-    final int payloadLengthInBytes = CompactFieldCodec.decodeNonNegativeInt(source);
-    final int payloadFlags = CompactFieldCodec.decodeNonNegativeInt(source);
-    target.set(payloadPointer, payloadLengthInBytes, payloadFlags);
-  }
-
-  public record SlotHeader(long nodeKey, NodeKind nodeKind, int fixedSlotSizeInBytes, int payloadSizeInBytes) {
-    public SlotHeader {
-      Objects.requireNonNull(nodeKind, "nodeKind must not be null");
-      if (fixedSlotSizeInBytes < 0) {
-        throw new IllegalArgumentException("fixedSlotSizeInBytes must be >= 0");
-      }
-      if (payloadSizeInBytes < 0) {
-        throw new IllegalArgumentException("payloadSizeInBytes must be >= 0");
-      }
-    }
-  }
-
-  public record PayloadBlockHeader(long payloadPointer, int payloadLengthInBytes, int payloadFlags) {
-    public PayloadBlockHeader {
-      if (payloadLengthInBytes < 0) {
-        throw new IllegalArgumentException("payloadLengthInBytes must be >= 0");
-      }
-      if (payloadFlags < 0) {
-        throw new IllegalArgumentException("payloadFlags must be >= 0");
-      }
-    }
-  }
-
-  /**
-   * Reusable mutable slot header container for allocation-free decode loops.
-   */
-  public static final class MutableSlotHeader {
-    private long nodeKey;
-    private NodeKind nodeKind;
-    private int fixedSlotSizeInBytes;
-    private int payloadSizeInBytes;
-
-    public long nodeKey() {
-      return nodeKey;
-    }
-
-    public NodeKind nodeKind() {
-      return nodeKind;
-    }
-
-    public int fixedSlotSizeInBytes() {
-      return fixedSlotSizeInBytes;
-    }
-
-    public int payloadSizeInBytes() {
-      return payloadSizeInBytes;
-    }
-
-    private void set(final long nodeKey, final NodeKind nodeKind, final int fixedSlotSizeInBytes,
-        final int payloadSizeInBytes) {
-      this.nodeKey = nodeKey;
-      this.nodeKind = nodeKind;
-      this.fixedSlotSizeInBytes = fixedSlotSizeInBytes;
-      this.payloadSizeInBytes = payloadSizeInBytes;
-    }
-  }
-
-  /**
-   * Reusable mutable payload block header for allocation-free decode loops.
-   */
-  public static final class MutablePayloadBlockHeader {
-    private long payloadPointer;
-    private int payloadLengthInBytes;
-    private int payloadFlags;
-
-    public long payloadPointer() {
-      return payloadPointer;
-    }
-
-    public int payloadLengthInBytes() {
-      return payloadLengthInBytes;
-    }
-
-    public int payloadFlags() {
-      return payloadFlags;
-    }
-
-    private void set(final long payloadPointer, final int payloadLengthInBytes, final int payloadFlags) {
-      this.payloadPointer = payloadPointer;
-      this.payloadLengthInBytes = payloadLengthInBytes;
-      this.payloadFlags = payloadFlags;
-    }
-  }
-}
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/layout/FixedSlotRecordMaterializer.java b/bundles/sirix-core/src/main/java/io/sirix/node/layout/FixedSlotRecordMaterializer.java
deleted file mode 100644
index 29ea31891..000000000
--- a/bundles/sirix-core/src/main/java/io/sirix/node/layout/FixedSlotRecordMaterializer.java
+++ /dev/null
@@ -1,976 +0,0 @@
-package io.sirix.node.layout;
-
-import io.brackit.query.atomic.QNm;
-import io.sirix.access.ResourceConfiguration;
-import io.sirix.node.MemorySegmentBytesIn;
-import io.sirix.node.NodeKind;
-import io.sirix.node.interfaces.DataRecord;
-import io.sirix.node.interfaces.StructNode;
-import io.sirix.node.json.ArrayNode;
-import io.sirix.node.json.BooleanNode;
-import io.sirix.node.json.JsonDocumentRootNode;
-import io.sirix.node.json.NullNode;
-import io.sirix.node.json.NumberNode;
-import io.sirix.node.json.ObjectBooleanNode;
-import io.sirix.node.json.ObjectKeyNode;
-import io.sirix.node.json.ObjectNode;
-import io.sirix.node.json.ObjectNullNode;
-import io.sirix.node.json.ObjectNumberNode;
-import io.sirix.node.json.ObjectStringNode;
-import io.sirix.node.json.StringNode;
-import io.sirix.node.interfaces.ValueNode;
-import io.sirix.node.xml.AttributeNode;
-import io.sirix.node.xml.CommentNode;
-import io.sirix.node.xml.ElementNode;
-import io.sirix.node.xml.NamespaceNode;
-import io.sirix.node.xml.PINode;
-import io.sirix.node.xml.TextNode;
-import io.sirix.node.xml.XmlDocumentRootNode;
-import io.sirix.settings.Fixed;
-import net.openhft.hashing.LongHashFunction;
-
-import java.lang.foreign.ValueLayout;
-
-import java.lang.foreign.MemorySegment;
-
-/**
- * Materializes {@link DataRecord} instances from fixed-slot in-memory layouts.
- *
- * 

- * Supports both payload-free node kinds and inline-payload node kinds (strings, numbers). Each call
- * allocates a fresh Java object. This is required because the write path (e.g.
- * {@code adaptForInsert}, {@code rollingAdd}) holds live references to multiple records of the same
- * kind simultaneously — singletons would cause aliasing corruption.
- * 

- */
-public final class FixedSlotRecordMaterializer {
-  private static final QNm EMPTY_QNM = new QNm("");
-
-  private FixedSlotRecordMaterializer() {}
-
-  /**
-   * Populate an existing DataRecord singleton from fixed-slot bytes at the given offset within
-   * {@code data} (zero allocation — avoids {@code asSlice()}).
-   *
-   * 

-   * This method reads structural fields, metadata, and inline payloads from the fixed-slot
-   * MemorySegment into the existing object's setters. For payload-bearing nodes (strings, numbers),
-   * uses lazy value loading via {@code setLazyRawValue}/{@code setLazyNumberValue} to defer byte[]
-   * allocation until the value is actually accessed.
-   * 

-   *
-   * 

-   * CRITICAL: For payload-bearing nodes, {@code setLazyRawValue}/{@code setLazyNumberValue}
-   * resets hash to 0. Therefore hash must be set AFTER the lazy value call.
-   * 

-   *
-   * @param existing the singleton to populate (must be the correct type for nodeKind)
-   * @param nodeKind the node kind
-   * @param nodeKey the record key
-   * @param data the backing MemorySegment (may be the full slotMemory)
-   * @param dataOffset absolute byte offset within {@code data} where this slot's data begins
-   * @param dataLength length of the slot data in bytes
-   * @param deweyIdBytes optional DeweyID bytes
-   * @param resourceConfig resource configuration (unused but kept for API consistency)
-   * @return true if the singleton was populated, false if the node kind is unsupported
-   */
-  public static boolean populateExisting(final DataRecord existing, final NodeKind nodeKind, final long nodeKey,
-      final MemorySegment data, final long dataOffset, final int dataLength, final byte[] deweyIdBytes,
-      final ResourceConfiguration resourceConfig) {
-    if (existing == null || nodeKind == null || data == null) {
-      return false;
-    }
-
-    final NodeKindLayout layout = nodeKind.layoutDescriptor();
-    if (!layout.isFixedSlotSupported() || dataLength < layout.fixedSlotSizeInBytes()) {
-      return false;
-    }
-
-    if (!layout.hasSupportedPayloads()) {
-      return false;
-    }
-
-    return switch (nodeKind) {
-      case JSON_DOCUMENT -> {
-        if (!(existing instanceof JsonDocumentRootNode node)) {
-          yield false;
-        }
-        node.setNodeKey(nodeKey);
-        populateJsonDocumentFields(node, data, dataOffset, layout);
-        node.setDeweyIDBytes(deweyIdBytes);
-        yield true;
-      }
-      case XML_DOCUMENT -> {
-        if (!(existing instanceof XmlDocumentRootNode node)) {
-          yield false;
-        }
-        node.setNodeKey(nodeKey);
-        node.setFirstChildKey(
-            SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.FIRST_CHILD_KEY));
-        node.setLastChildKey(
-            SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.LAST_CHILD_KEY));
-        node.setChildCount(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.CHILD_COUNT));
-        node.setDescendantCount(
-            SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.DESCENDANT_COUNT));
-        node.setHash(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.HASH));
-        node.setDeweyIDBytes(deweyIdBytes);
-        yield true;
-      }
-      case OBJECT -> {
-        if (!(existing instanceof ObjectNode node)) {
-          yield false;
-        }
-        node.setNodeKey(nodeKey);
-        populateObjectFields(node, data, dataOffset, layout);
-        node.setDeweyIDBytes(deweyIdBytes);
-        yield true;
-      }
-      case ARRAY -> {
-        if (!(existing instanceof ArrayNode node)) {
-          yield false;
-        }
-        node.setNodeKey(nodeKey);
-        populateArrayFields(node, data, dataOffset, layout);
-        node.setPathNodeKey(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.PATH_NODE_KEY));
-        node.setDeweyIDBytes(deweyIdBytes);
-        yield true;
-      }
-      case OBJECT_KEY -> {
-        if (!(existing instanceof ObjectKeyNode node)) {
-          yield false;
-        }
-        node.setNodeKey(nodeKey);
-        node.setParentKey(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.PARENT_KEY));
-        node.setPathNodeKey(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.PATH_NODE_KEY));
-        node.setPreviousRevision(
-            SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.PREVIOUS_REVISION));
-        node.setLastModifiedRevision(
-            SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.LAST_MODIFIED_REVISION));
-        node.setRightSiblingKey(
-            SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.RIGHT_SIBLING_KEY));
-        node.setLeftSiblingKey(
-            SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.LEFT_SIBLING_KEY));
-        node.setFirstChildKey(
-            SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.FIRST_CHILD_KEY));
-        node.setNameKey(SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.NAME_KEY));
-        node.clearCachedName();
-        node.setDescendantCount(
-            SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.DESCENDANT_COUNT));
-        node.setHash(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.HASH));
-        node.setDeweyIDBytes(deweyIdBytes);
-        yield true;
-      }
-      case BOOLEAN_VALUE -> {
-        if (!(existing instanceof BooleanNode node)) {
-          yield false;
-        }
-        node.setNodeKey(nodeKey);
-        populateBooleanNodeFields(node, data, dataOffset, layout);
-        node.setDeweyIDBytes(deweyIdBytes);
-        yield true;
-      }
-      case NULL_VALUE -> {
-        if (!(existing instanceof NullNode node)) {
-          yield false;
-        }
-        node.setNodeKey(nodeKey);
-        populateLeafNodeFields(node, data, dataOffset, layout);
-        node.setDeweyIDBytes(deweyIdBytes);
-        yield true;
-      }
-      case OBJECT_BOOLEAN_VALUE -> {
-        if (!(existing instanceof ObjectBooleanNode node)) {
-          yield false;
-        }
-        node.setNodeKey(nodeKey);
-        node.setParentKey(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.PARENT_KEY));
-        node.setPreviousRevision(
-            SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.PREVIOUS_REVISION));
-        node.setLastModifiedRevision(
-            SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.LAST_MODIFIED_REVISION));
-        node.setHash(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.HASH));
-        node.setValue(SlotLayoutAccessors.readBooleanField(data, dataOffset, layout, StructuralField.BOOLEAN_VALUE));
-        node.setDeweyIDBytes(deweyIdBytes);
-        yield true;
-      }
-      case OBJECT_NULL_VALUE -> {
-        if (!(existing instanceof ObjectNullNode node)) {
-          yield false;
-        }
-        node.setNodeKey(nodeKey);
-        node.setParentKey(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.PARENT_KEY));
-        node.setPreviousRevision(
-            SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.PREVIOUS_REVISION));
-        node.setLastModifiedRevision(
-            SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.LAST_MODIFIED_REVISION));
-        node.setHash(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.HASH));
-        node.setDeweyIDBytes(deweyIdBytes);
-        yield true;
-      }
-      case NAMESPACE -> {
-        if (!(existing instanceof NamespaceNode node)) {
-          yield false;
-        }
-        node.setNodeKey(nodeKey);
-        node.setParentKey(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.PARENT_KEY));
-        node.setPreviousRevision(
-            SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.PREVIOUS_REVISION));
-        node.setLastModifiedRevision(
-            SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.LAST_MODIFIED_REVISION));
-        node.setPathNodeKey(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.PATH_NODE_KEY));
-        node.setPrefixKey(SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.PREFIX_KEY));
-        node.setLocalNameKey(
-            SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.LOCAL_NAME_KEY));
-        node.setURIKey(SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.URI_KEY));
-        node.setHash(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.HASH));
-        node.setName(EMPTY_QNM);
-        node.setDeweyIDBytes(deweyIdBytes);
-        yield true;
-      }
-      case ELEMENT -> {
-        if (!(existing instanceof ElementNode node)) {
-          yield false;
-        }
-        node.setNodeKey(nodeKey);
-        node.setParentKey(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.PARENT_KEY));
-        node.setRightSiblingKey(
-            SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.RIGHT_SIBLING_KEY));
-        node.setLeftSiblingKey(
-            SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.LEFT_SIBLING_KEY));
-        node.setFirstChildKey(
-            SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.FIRST_CHILD_KEY));
-        node.setLastChildKey(
-            SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.LAST_CHILD_KEY));
-        node.setPathNodeKey(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.PATH_NODE_KEY));
-        node.setPrefixKey(SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.PREFIX_KEY));
-        node.setLocalNameKey(
-            SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.LOCAL_NAME_KEY));
-        node.setURIKey(SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.URI_KEY));
-        node.setPreviousRevision(
-            SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.PREVIOUS_REVISION));
-        node.setLastModifiedRevision(
-            SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.LAST_MODIFIED_REVISION));
-        node.setChildCount(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.CHILD_COUNT));
-        node.setDescendantCount(
-            SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.DESCENDANT_COUNT));
-        node.setHash(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.HASH));
-        readInlineVectorPayload(node, data, dataOffset, layout, 0, true);
-        readInlineVectorPayload(node, data, dataOffset, layout, 1, false);
-        node.setName(EMPTY_QNM);
-        node.setDeweyIDBytes(deweyIdBytes);
-        yield true;
-      }
-      case STRING_VALUE -> {
-        if (!(existing instanceof StringNode node)) {
-          yield false;
-        }
-        node.setNodeKey(nodeKey);
-        populateLeafNodeFields(node, data, dataOffset, layout);
-        // setLazyRawValue BEFORE setHash — setLazyRawValue resets hash to 0
-        final long strPointer = SlotLayoutAccessors.readPayloadPointer(data, dataOffset, layout, 0);
-        final int strLength = SlotLayoutAccessors.readPayloadLength(data, dataOffset, layout, 0);
-        final int strFlags = SlotLayoutAccessors.readPayloadFlags(data, dataOffset, layout, 0);
-        node.setLazyRawValue(data, dataOffset + strPointer, strLength, (strFlags & 1) != 0);
-        node.setHash(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.HASH));
-        node.setDeweyIDBytes(deweyIdBytes);
-        yield true;
-      }
-      case NUMBER_VALUE -> {
-        if (!(existing instanceof NumberNode node)) {
-          yield false;
-        }
-        node.setNodeKey(nodeKey);
-        populateLeafNodeFields(node, data, dataOffset, layout);
-        // setLazyNumberValue BEFORE setHash — setLazyNumberValue resets hash to 0
-        final long numPointer = SlotLayoutAccessors.readPayloadPointer(data, dataOffset, layout, 0);
-        final int numLength = SlotLayoutAccessors.readPayloadLength(data, dataOffset, layout, 0);
-        node.setLazyNumberValue(data, dataOffset + numPointer, numLength);
-        node.setHash(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.HASH));
-        node.setDeweyIDBytes(deweyIdBytes);
-        yield true;
-      }
-      case OBJECT_STRING_VALUE -> {
-        if (!(existing instanceof ObjectStringNode node)) {
-          yield false;
-        }
-        node.setNodeKey(nodeKey);
-        node.setParentKey(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.PARENT_KEY));
-        node.setPreviousRevision(
-            SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.PREVIOUS_REVISION));
-        node.setLastModifiedRevision(
-            SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.LAST_MODIFIED_REVISION));
-        // setLazyRawValue BEFORE setHash — setLazyRawValue resets hash to 0
-        final long objStrPointer = SlotLayoutAccessors.readPayloadPointer(data, dataOffset, layout, 0);
-        final int objStrLength = SlotLayoutAccessors.readPayloadLength(data, dataOffset, layout, 0);
-        final int objStrFlags = SlotLayoutAccessors.readPayloadFlags(data, dataOffset, layout, 0);
-        node.setLazyRawValue(data, dataOffset + objStrPointer, objStrLength, (objStrFlags & 1) != 0);
-        node.setHash(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.HASH));
-        node.setDeweyIDBytes(deweyIdBytes);
-        yield true;
-      }
-      case OBJECT_NUMBER_VALUE -> {
-        if (!(existing instanceof ObjectNumberNode node)) {
-          yield false;
-        }
-        node.setNodeKey(nodeKey);
-        node.setParentKey(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.PARENT_KEY));
-        node.setPreviousRevision(
-            SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.PREVIOUS_REVISION));
-        node.setLastModifiedRevision(
-            SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.LAST_MODIFIED_REVISION));
-        // setLazyNumberValue BEFORE setHash — setLazyNumberValue resets hash to 0
-        final long objNumPointer = SlotLayoutAccessors.readPayloadPointer(data, dataOffset, layout, 0);
-        final int objNumLength = SlotLayoutAccessors.readPayloadLength(data, dataOffset, layout, 0);
-        node.setLazyNumberValue(data, dataOffset + objNumPointer, objNumLength);
-        node.setHash(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.HASH));
-        node.setDeweyIDBytes(deweyIdBytes);
-        yield true;
-      }
-      case TEXT -> {
-        if (!(existing instanceof TextNode node)) {
-          yield false;
-        }
-        node.setNodeKey(nodeKey);
-        populateLeafNodeFields(node, data, dataOffset, layout);
-        // setLazyRawValue BEFORE setHash — setLazyRawValue resets hash to 0
-        final long textPointer = SlotLayoutAccessors.readPayloadPointer(data, dataOffset, layout, 0);
-        final int textLength = SlotLayoutAccessors.readPayloadLength(data, dataOffset, layout, 0);
-        final int textFlags = SlotLayoutAccessors.readPayloadFlags(data, dataOffset, layout, 0);
-        node.setLazyRawValue(data, dataOffset + textPointer, textLength, (textFlags & 1) != 0);
-        node.setHash(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.HASH));
-        node.setDeweyIDBytes(deweyIdBytes);
-        yield true;
-      }
-      case COMMENT -> {
-        if (!(existing instanceof CommentNode node)) {
-          yield false;
-        }
-        node.setNodeKey(nodeKey);
-        populateLeafNodeFields(node, data, dataOffset, layout);
-        // setLazyRawValue BEFORE setHash — setLazyRawValue resets hash to 0
-        final long commentPointer = SlotLayoutAccessors.readPayloadPointer(data, dataOffset, layout, 0);
-        final int commentLength = SlotLayoutAccessors.readPayloadLength(data, dataOffset, layout, 0);
-        final int commentFlags = SlotLayoutAccessors.readPayloadFlags(data, dataOffset, layout, 0);
-        node.setLazyRawValue(data, dataOffset + commentPointer, commentLength, (commentFlags & 1) != 0);
-        node.setHash(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.HASH));
-        node.setDeweyIDBytes(deweyIdBytes);
-        yield true;
-      }
-      case ATTRIBUTE -> {
-        if (!(existing instanceof AttributeNode node)) {
-          yield false;
-        }
-        node.setNodeKey(nodeKey);
-        node.setParentKey(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.PARENT_KEY));
-        node.setPathNodeKey(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.PATH_NODE_KEY));
-        node.setPrefixKey(SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.PREFIX_KEY));
-        node.setLocalNameKey(
-            SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.LOCAL_NAME_KEY));
-        node.setURIKey(SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.URI_KEY));
-        node.setPreviousRevision(
-            SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.PREVIOUS_REVISION));
-        node.setLastModifiedRevision(
-            SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.LAST_MODIFIED_REVISION));
-        // setLazyRawValue BEFORE setHash — setLazyRawValue resets hash to 0
-        final long attrPointer = SlotLayoutAccessors.readPayloadPointer(data, dataOffset, layout, 0);
-        final int attrLength = SlotLayoutAccessors.readPayloadLength(data, dataOffset, layout, 0);
-        node.setLazyRawValue(data, dataOffset + attrPointer, attrLength);
-        node.setHash(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.HASH));
-        node.setName(EMPTY_QNM);
-        node.setDeweyIDBytes(deweyIdBytes);
-        yield true;
-      }
-      case PROCESSING_INSTRUCTION -> {
-        if (!(existing instanceof PINode node)) {
-          yield false;
-        }
-        node.setNodeKey(nodeKey);
-        node.setParentKey(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.PARENT_KEY));
-        node.setRightSiblingKey(
-            SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.RIGHT_SIBLING_KEY));
-        node.setLeftSiblingKey(
-            SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.LEFT_SIBLING_KEY));
-        node.setFirstChildKey(
-            SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.FIRST_CHILD_KEY));
-        node.setLastChildKey(
-            SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.LAST_CHILD_KEY));
-        node.setPathNodeKey(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.PATH_NODE_KEY));
-        node.setPrefixKey(SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.PREFIX_KEY));
-        node.setLocalNameKey(
-            SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.LOCAL_NAME_KEY));
-        node.setURIKey(SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.URI_KEY));
-        node.setPreviousRevision(
-            SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.PREVIOUS_REVISION));
-        node.setLastModifiedRevision(
-            SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.LAST_MODIFIED_REVISION));
-        node.setChildCount(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.CHILD_COUNT));
-        node.setDescendantCount(
-            SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.DESCENDANT_COUNT));
-        // setLazyRawValue BEFORE setHash — setLazyRawValue resets hash to 0
-        final long piPointer = SlotLayoutAccessors.readPayloadPointer(data, dataOffset, layout, 0);
-        final int piLength = SlotLayoutAccessors.readPayloadLength(data, dataOffset, layout, 0);
-        final int piFlags = SlotLayoutAccessors.readPayloadFlags(data, dataOffset, layout, 0);
-        node.setLazyRawValue(data, dataOffset + piPointer, piLength, (piFlags & 1) != 0);
-        node.setHash(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.HASH));
-        node.setName(EMPTY_QNM);
-        node.setDeweyIDBytes(deweyIdBytes);
-        yield true;
-      }
-      default -> false;
-    };
-  }
-
-  /**
-   * Populate common structural fields for an ObjectNode.
-   */
-  private static void populateObjectFields(final ObjectNode node, final MemorySegment data, final long dataOffset,
-      final NodeKindLayout layout) {
-    node.setParentKey(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.PARENT_KEY));
-    node.setPreviousRevision(
-        SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.PREVIOUS_REVISION));
-    node.setLastModifiedRevision(
-        SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.LAST_MODIFIED_REVISION));
-    node.setRightSiblingKey(
-        SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.RIGHT_SIBLING_KEY));
-    node.setLeftSiblingKey(
-        SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.LEFT_SIBLING_KEY));
-    node.setFirstChildKey(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.FIRST_CHILD_KEY));
-    node.setLastChildKey(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.LAST_CHILD_KEY));
-    node.setChildCount(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.CHILD_COUNT));
-    node.setDescendantCount(
-        SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.DESCENDANT_COUNT));
-    node.setHash(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.HASH));
-  }
-
-  /**
-   * Populate common structural fields for an ArrayNode.
-   */
-  private static void populateArrayFields(final ArrayNode node, final MemorySegment data, final long dataOffset,
-      final NodeKindLayout layout) {
-    node.setParentKey(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.PARENT_KEY));
-    node.setPreviousRevision(
-        SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.PREVIOUS_REVISION));
-    node.setLastModifiedRevision(
-        SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.LAST_MODIFIED_REVISION));
-    node.setRightSiblingKey(
-        SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.RIGHT_SIBLING_KEY));
-    node.setLeftSiblingKey(
-        SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.LEFT_SIBLING_KEY));
-    node.setFirstChildKey(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.FIRST_CHILD_KEY));
-    node.setLastChildKey(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.LAST_CHILD_KEY));
-    node.setChildCount(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.CHILD_COUNT));
-    node.setDescendantCount(
-        SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.DESCENDANT_COUNT));
-    node.setHash(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.HASH));
-  }
-
-  /**
-   * Populate fields for a JsonDocumentRootNode.
-   */
-  private static void populateJsonDocumentFields(final JsonDocumentRootNode node, final MemorySegment data,
-      final long dataOffset, final NodeKindLayout layout) {
-    node.setParentKey(Fixed.NULL_NODE_KEY.getStandardProperty());
-    node.setRightSiblingKey(Fixed.NULL_NODE_KEY.getStandardProperty());
-    node.setLeftSiblingKey(Fixed.NULL_NODE_KEY.getStandardProperty());
-    node.setFirstChildKey(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.FIRST_CHILD_KEY));
-    node.setLastChildKey(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.LAST_CHILD_KEY));
-    node.setChildCount(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.CHILD_COUNT));
-    node.setDescendantCount(
-        SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.DESCENDANT_COUNT));
-    node.setHash(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.HASH));
-    node.setPreviousRevision(0);
-    node.setLastModifiedRevision(0);
-  }
-
-  /**
-   * Populate common fields for leaf nodes with siblings.
-   */
-  private static void populateLeafNodeFields(final StructNode node, final MemorySegment data, final long dataOffset,
-      final NodeKindLayout layout) {
-    node.setParentKey(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.PARENT_KEY));
-    node.setPreviousRevision(
-        SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.PREVIOUS_REVISION));
-    node.setLastModifiedRevision(
-        SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.LAST_MODIFIED_REVISION));
-    node.setRightSiblingKey(
-        SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.RIGHT_SIBLING_KEY));
-    node.setLeftSiblingKey(
-        SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.LEFT_SIBLING_KEY));
-    node.setHash(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.HASH));
-  }
-
-  /**
-   * Populate fields for a BooleanNode (has siblings + boolean value).
-   */
-  private static void populateBooleanNodeFields(final BooleanNode node, final MemorySegment data, final long dataOffset,
-      final NodeKindLayout layout) {
-    node.setParentKey(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.PARENT_KEY));
-    node.setPreviousRevision(
-        SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.PREVIOUS_REVISION));
-    node.setLastModifiedRevision(
-        SlotLayoutAccessors.readIntField(data, dataOffset, layout, StructuralField.LAST_MODIFIED_REVISION));
-    node.setRightSiblingKey(
-        SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.RIGHT_SIBLING_KEY));
-    node.setLeftSiblingKey(
-        SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.LEFT_SIBLING_KEY));
-    node.setHash(SlotLayoutAccessors.readLongField(data, dataOffset, layout, StructuralField.HASH));
-    node.setValue(SlotLayoutAccessors.readBooleanField(data, dataOffset, layout, StructuralField.BOOLEAN_VALUE));
-  }
-
-  /**
-   * Materialize a fixed-slot record.
-   *
-   * @param nodeKind node kind metadata for this slot
-   * @param nodeKey record key
-   * @param data fixed-slot bytes (header + optional inline payload)
-   * @param deweyIdBytes optional DeweyID bytes
-   * @param resourceConfig resource configuration
-   * @return materialized record, or {@code null} if this slot cannot be materialized as fixed format
-   */
-  public static DataRecord materialize(final NodeKind nodeKind, final long nodeKey, final MemorySegment data,
-      final byte[] deweyIdBytes, final ResourceConfiguration resourceConfig) {
-    if (nodeKind == null || data == null || resourceConfig == null) {
-      return null;
-    }
-
-    final NodeKindLayout layout = nodeKind.layoutDescriptor();
-    if (!layout.isFixedSlotSupported() || data.byteSize() < layout.fixedSlotSizeInBytes()) {
-      return null;
-    }
-
-    if (!layout.hasSupportedPayloads()) {
-      return null;
-    }
-
-    final LongHashFunction hashFunction = resourceConfig.nodeHashFunction;
-    final long nullNodeKey = Fixed.NULL_NODE_KEY.getStandardProperty();
-
-    return switch (nodeKind) {
-      case JSON_DOCUMENT -> {
-        final JsonDocumentRootNode node = new JsonDocumentRootNode(nodeKey, 0, 0, 0, 0, hashFunction);
-        node.setParentKey(nullNodeKey);
-        node.setRightSiblingKey(nullNodeKey);
-        node.setLeftSiblingKey(nullNodeKey);
-        node.setFirstChildKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.FIRST_CHILD_KEY));
-        node.setLastChildKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.LAST_CHILD_KEY));
-        node.setChildCount(SlotLayoutAccessors.readLongField(data, layout, StructuralField.CHILD_COUNT));
-        node.setDescendantCount(SlotLayoutAccessors.readLongField(data, layout, StructuralField.DESCENDANT_COUNT));
-        node.setHash(SlotLayoutAccessors.readLongField(data, layout, StructuralField.HASH));
-        node.setPreviousRevision(0);
-        node.setLastModifiedRevision(0);
-        node.setDeweyIDBytes(deweyIdBytes);
-        yield node;
-      }
-      case XML_DOCUMENT -> {
-        final XmlDocumentRootNode node = new XmlDocumentRootNode(nodeKey, 0, 0, 0, 0, hashFunction);
-        node.setFirstChildKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.FIRST_CHILD_KEY));
-        node.setLastChildKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.LAST_CHILD_KEY));
-        node.setChildCount(SlotLayoutAccessors.readLongField(data, layout, StructuralField.CHILD_COUNT));
-        node.setDescendantCount(SlotLayoutAccessors.readLongField(data, layout, StructuralField.DESCENDANT_COUNT));
-        node.setHash(SlotLayoutAccessors.readLongField(data, layout, StructuralField.HASH));
-        node.setDeweyIDBytes(deweyIdBytes);
-        yield node;
-      }
-      case OBJECT -> {
-        final ObjectNode node = new ObjectNode(nodeKey, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, hashFunction, deweyIdBytes);
-        node.setParentKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.PARENT_KEY));
-        node.setPreviousRevision(SlotLayoutAccessors.readIntField(data, layout, StructuralField.PREVIOUS_REVISION));
-        node.setLastModifiedRevision(
-            SlotLayoutAccessors.readIntField(data, layout, StructuralField.LAST_MODIFIED_REVISION));
-        node.setRightSiblingKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.RIGHT_SIBLING_KEY));
-        node.setLeftSiblingKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.LEFT_SIBLING_KEY));
-        node.setFirstChildKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.FIRST_CHILD_KEY));
-        node.setLastChildKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.LAST_CHILD_KEY));
-        node.setChildCount(SlotLayoutAccessors.readLongField(data, layout, StructuralField.CHILD_COUNT));
-        node.setDescendantCount(SlotLayoutAccessors.readLongField(data, layout, StructuralField.DESCENDANT_COUNT));
-        node.setHash(SlotLayoutAccessors.readLongField(data, layout, StructuralField.HASH));
-        yield node;
-      }
-      case ARRAY -> {
-        final ArrayNode node = new ArrayNode(nodeKey, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, hashFunction, deweyIdBytes);
-        node.setParentKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.PARENT_KEY));
-        node.setPathNodeKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.PATH_NODE_KEY));
-        node.setPreviousRevision(SlotLayoutAccessors.readIntField(data, layout, StructuralField.PREVIOUS_REVISION));
-        node.setLastModifiedRevision(
-            SlotLayoutAccessors.readIntField(data, layout, StructuralField.LAST_MODIFIED_REVISION));
-        node.setRightSiblingKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.RIGHT_SIBLING_KEY));
-        node.setLeftSiblingKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.LEFT_SIBLING_KEY));
-        node.setFirstChildKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.FIRST_CHILD_KEY));
-        node.setLastChildKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.LAST_CHILD_KEY));
-        node.setChildCount(SlotLayoutAccessors.readLongField(data, layout, StructuralField.CHILD_COUNT));
-        node.setDescendantCount(SlotLayoutAccessors.readLongField(data, layout, StructuralField.DESCENDANT_COUNT));
-        node.setHash(SlotLayoutAccessors.readLongField(data, layout, StructuralField.HASH));
-        yield node;
-      }
-      case OBJECT_KEY -> {
-        final ObjectKeyNode node = new ObjectKeyNode(nodeKey, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, hashFunction, deweyIdBytes);
-        node.setParentKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.PARENT_KEY));
-        node.setPathNodeKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.PATH_NODE_KEY));
-        node.setPreviousRevision(SlotLayoutAccessors.readIntField(data, layout, StructuralField.PREVIOUS_REVISION));
-        node.setLastModifiedRevision(
-            SlotLayoutAccessors.readIntField(data, layout, StructuralField.LAST_MODIFIED_REVISION));
-        node.setRightSiblingKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.RIGHT_SIBLING_KEY));
-        node.setLeftSiblingKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.LEFT_SIBLING_KEY));
-        node.setFirstChildKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.FIRST_CHILD_KEY));
-        node.setNameKey(SlotLayoutAccessors.readIntField(data, layout, StructuralField.NAME_KEY));
-        node.clearCachedName();
-        node.setDescendantCount(SlotLayoutAccessors.readLongField(data, layout, StructuralField.DESCENDANT_COUNT));
-        node.setHash(SlotLayoutAccessors.readLongField(data, layout, StructuralField.HASH));
-        yield node;
-      }
-      case BOOLEAN_VALUE -> {
-        final BooleanNode node = new BooleanNode(nodeKey, 0, 0, 0, 0, 0, 0, false, hashFunction, deweyIdBytes);
-        node.setParentKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.PARENT_KEY));
-        node.setPreviousRevision(SlotLayoutAccessors.readIntField(data, layout, StructuralField.PREVIOUS_REVISION));
-        node.setLastModifiedRevision(
-            SlotLayoutAccessors.readIntField(data, layout, StructuralField.LAST_MODIFIED_REVISION));
-        node.setRightSiblingKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.RIGHT_SIBLING_KEY));
-        node.setLeftSiblingKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.LEFT_SIBLING_KEY));
-        node.setHash(SlotLayoutAccessors.readLongField(data, layout, StructuralField.HASH));
-        node.setValue(SlotLayoutAccessors.readBooleanField(data, layout, StructuralField.BOOLEAN_VALUE));
-        yield node;
-      }
-      case NULL_VALUE -> {
-        final NullNode node = new NullNode(nodeKey, 0, 0, 0, 0, 0, 0, hashFunction, deweyIdBytes);
-        node.setParentKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.PARENT_KEY));
-        node.setPreviousRevision(SlotLayoutAccessors.readIntField(data, layout, StructuralField.PREVIOUS_REVISION));
-        node.setLastModifiedRevision(
-            SlotLayoutAccessors.readIntField(data, layout, StructuralField.LAST_MODIFIED_REVISION));
-        node.setRightSiblingKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.RIGHT_SIBLING_KEY));
-        node.setLeftSiblingKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.LEFT_SIBLING_KEY));
-        node.setHash(SlotLayoutAccessors.readLongField(data, layout, StructuralField.HASH));
-        yield node;
-      }
-      case OBJECT_BOOLEAN_VALUE -> {
-        final ObjectBooleanNode node = new ObjectBooleanNode(nodeKey, 0, 0, 0, 0, false, hashFunction, deweyIdBytes);
-        node.setParentKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.PARENT_KEY));
-        node.setPreviousRevision(SlotLayoutAccessors.readIntField(data, layout, StructuralField.PREVIOUS_REVISION));
-        node.setLastModifiedRevision(
-            SlotLayoutAccessors.readIntField(data, layout, StructuralField.LAST_MODIFIED_REVISION));
-        node.setHash(SlotLayoutAccessors.readLongField(data, layout, StructuralField.HASH));
-        node.setValue(SlotLayoutAccessors.readBooleanField(data, layout, StructuralField.BOOLEAN_VALUE));
-        yield node;
-      }
-      case OBJECT_NULL_VALUE -> {
-        final ObjectNullNode node = new ObjectNullNode(nodeKey, 0, 0, 0, 0, hashFunction, deweyIdBytes);
-        node.setParentKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.PARENT_KEY));
-        node.setPreviousRevision(SlotLayoutAccessors.readIntField(data, layout, StructuralField.PREVIOUS_REVISION));
-        node.setLastModifiedRevision(
-            SlotLayoutAccessors.readIntField(data, layout, StructuralField.LAST_MODIFIED_REVISION));
-        node.setHash(SlotLayoutAccessors.readLongField(data, layout, StructuralField.HASH));
-        yield node;
-      }
-      case NAMESPACE -> {
-        final NamespaceNode node =
-            new NamespaceNode(nodeKey, 0, 0, 0, 0, 0, 0, 0, 0, hashFunction, deweyIdBytes, EMPTY_QNM);
-        node.setParentKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.PARENT_KEY));
-        node.setPreviousRevision(SlotLayoutAccessors.readIntField(data, layout, StructuralField.PREVIOUS_REVISION));
-        node.setLastModifiedRevision(
-            SlotLayoutAccessors.readIntField(data, layout, StructuralField.LAST_MODIFIED_REVISION));
-        node.setPathNodeKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.PATH_NODE_KEY));
-        node.setPrefixKey(SlotLayoutAccessors.readIntField(data, layout, StructuralField.PREFIX_KEY));
-        node.setLocalNameKey(SlotLayoutAccessors.readIntField(data, layout, StructuralField.LOCAL_NAME_KEY));
-        node.setURIKey(SlotLayoutAccessors.readIntField(data, layout, StructuralField.URI_KEY));
-        node.setHash(SlotLayoutAccessors.readLongField(data, layout, StructuralField.HASH));
-        node.setName(EMPTY_QNM);
-        yield node;
-      }
-      case ELEMENT -> {
-        final ElementNode node = new ElementNode(nodeKey, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, hashFunction,
-            deweyIdBytes, null, null, EMPTY_QNM);
-        node.setParentKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.PARENT_KEY));
-        node.setRightSiblingKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.RIGHT_SIBLING_KEY));
-        node.setLeftSiblingKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.LEFT_SIBLING_KEY));
-        node.setFirstChildKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.FIRST_CHILD_KEY));
-        node.setLastChildKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.LAST_CHILD_KEY));
-        node.setPathNodeKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.PATH_NODE_KEY));
-        node.setPrefixKey(SlotLayoutAccessors.readIntField(data, layout, StructuralField.PREFIX_KEY));
-        node.setLocalNameKey(SlotLayoutAccessors.readIntField(data, layout, StructuralField.LOCAL_NAME_KEY));
-        node.setURIKey(SlotLayoutAccessors.readIntField(data, layout, StructuralField.URI_KEY));
-        node.setPreviousRevision(SlotLayoutAccessors.readIntField(data, layout, StructuralField.PREVIOUS_REVISION));
-        node.setLastModifiedRevision(
-            SlotLayoutAccessors.readIntField(data, layout, StructuralField.LAST_MODIFIED_REVISION));
-        node.setChildCount(SlotLayoutAccessors.readLongField(data, layout, StructuralField.CHILD_COUNT));
-        node.setDescendantCount(SlotLayoutAccessors.readLongField(data, layout, StructuralField.DESCENDANT_COUNT));
-        node.setHash(SlotLayoutAccessors.readLongField(data, layout, StructuralField.HASH));
-        readInlineVectorPayload(node, data, layout, 0, true);
-        readInlineVectorPayload(node, data, layout, 1, false);
-        node.setName(EMPTY_QNM);
-        yield node;
-      }
-      case STRING_VALUE -> {
-        final StringNode node = new StringNode(nodeKey, 0, 0, 0, 0, 0, 0, new byte[0], hashFunction, deweyIdBytes);
-        node.setParentKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.PARENT_KEY));
-        node.setRightSiblingKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.RIGHT_SIBLING_KEY));
-        node.setLeftSiblingKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.LEFT_SIBLING_KEY));
-        node.setPreviousRevision(SlotLayoutAccessors.readIntField(data, layout, StructuralField.PREVIOUS_REVISION));
-        node.setLastModifiedRevision(
-            SlotLayoutAccessors.readIntField(data, layout, StructuralField.LAST_MODIFIED_REVISION));
-        node.setHash(SlotLayoutAccessors.readLongField(data, layout, StructuralField.HASH));
-        readInlineStringPayload(node, data, layout, 0);
-        yield node;
-      }
-      case NUMBER_VALUE -> {
-        final NumberNode node = new NumberNode(nodeKey, 0, 0, 0, 0, 0, 0, 0, hashFunction, deweyIdBytes);
-        node.setParentKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.PARENT_KEY));
-        node.setRightSiblingKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.RIGHT_SIBLING_KEY));
-        node.setLeftSiblingKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.LEFT_SIBLING_KEY));
-        node.setPreviousRevision(SlotLayoutAccessors.readIntField(data, layout, StructuralField.PREVIOUS_REVISION));
-        node.setLastModifiedRevision(
-            SlotLayoutAccessors.readIntField(data, layout, StructuralField.LAST_MODIFIED_REVISION));
-        node.setHash(SlotLayoutAccessors.readLongField(data, layout, StructuralField.HASH));
-        readInlineNumberPayload(node, data, layout, 0);
-        yield node;
-      }
-      case OBJECT_STRING_VALUE -> {
-        final ObjectStringNode node =
-            new ObjectStringNode(nodeKey, 0, 0, 0, 0, new byte[0], hashFunction, deweyIdBytes);
-        node.setParentKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.PARENT_KEY));
-        node.setPreviousRevision(SlotLayoutAccessors.readIntField(data, layout, StructuralField.PREVIOUS_REVISION));
-        node.setLastModifiedRevision(
-            SlotLayoutAccessors.readIntField(data, layout, StructuralField.LAST_MODIFIED_REVISION));
-        node.setHash(SlotLayoutAccessors.readLongField(data, layout, StructuralField.HASH));
-        readInlineObjectStringPayload(node, data, layout, 0);
-        yield node;
-      }
-      case OBJECT_NUMBER_VALUE -> {
-        final ObjectNumberNode node = new ObjectNumberNode(nodeKey, 0, 0, 0, 0, 0, hashFunction, deweyIdBytes);
-        node.setParentKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.PARENT_KEY));
-        node.setPreviousRevision(SlotLayoutAccessors.readIntField(data, layout, StructuralField.PREVIOUS_REVISION));
-        node.setLastModifiedRevision(
-            SlotLayoutAccessors.readIntField(data, layout, StructuralField.LAST_MODIFIED_REVISION));
-        node.setHash(SlotLayoutAccessors.readLongField(data, layout, StructuralField.HASH));
-        readInlineNumberPayloadForObject(node, data, layout, 0);
-        yield node;
-      }
-      case TEXT -> {
-        final TextNode node = new TextNode(nodeKey, 0, 0, 0, 0, 0, 0, new byte[0], false, hashFunction, deweyIdBytes);
-        node.setParentKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.PARENT_KEY));
-        node.setRightSiblingKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.RIGHT_SIBLING_KEY));
-        node.setLeftSiblingKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.LEFT_SIBLING_KEY));
-        node.setPreviousRevision(SlotLayoutAccessors.readIntField(data, layout, StructuralField.PREVIOUS_REVISION));
-        node.setLastModifiedRevision(
-            SlotLayoutAccessors.readIntField(data, layout, StructuralField.LAST_MODIFIED_REVISION));
-        // setRawValue BEFORE setHash — setRawValue resets hash to 0
-        readInlineXmlValuePayload(node, data, layout, 0);
-        node.setHash(SlotLayoutAccessors.readLongField(data, layout, StructuralField.HASH));
-        yield node;
-      }
-      case COMMENT -> {
-        final CommentNode node =
-            new CommentNode(nodeKey, 0, 0, 0, 0, 0, 0, new byte[0], false, hashFunction, deweyIdBytes);
-        node.setParentKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.PARENT_KEY));
-        node.setRightSiblingKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.RIGHT_SIBLING_KEY));
-        node.setLeftSiblingKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.LEFT_SIBLING_KEY));
-        node.setPreviousRevision(SlotLayoutAccessors.readIntField(data, layout, StructuralField.PREVIOUS_REVISION));
-        node.setLastModifiedRevision(
-            SlotLayoutAccessors.readIntField(data, layout, StructuralField.LAST_MODIFIED_REVISION));
-        // setRawValue BEFORE setHash — setRawValue resets hash to 0
-        readInlineXmlValuePayload(node, data, layout, 0);
-        node.setHash(SlotLayoutAccessors.readLongField(data, layout, StructuralField.HASH));
-        yield node;
-      }
-      case ATTRIBUTE -> {
-        final AttributeNode node =
-            new AttributeNode(nodeKey, 0, 0, 0, 0, 0, 0, 0, 0, new byte[0], hashFunction, deweyIdBytes, EMPTY_QNM);
-        node.setParentKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.PARENT_KEY));
-        node.setPathNodeKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.PATH_NODE_KEY));
-        node.setPrefixKey(SlotLayoutAccessors.readIntField(data, layout, StructuralField.PREFIX_KEY));
-        node.setLocalNameKey(SlotLayoutAccessors.readIntField(data, layout, StructuralField.LOCAL_NAME_KEY));
-        node.setURIKey(SlotLayoutAccessors.readIntField(data, layout, StructuralField.URI_KEY));
-        node.setPreviousRevision(SlotLayoutAccessors.readIntField(data, layout, StructuralField.PREVIOUS_REVISION));
-        node.setLastModifiedRevision(
-            SlotLayoutAccessors.readIntField(data, layout, StructuralField.LAST_MODIFIED_REVISION));
-        // setRawValue BEFORE setHash — setRawValue resets hash to 0
-        readInlineXmlValuePayload(node, data, layout, 0);
-        node.setHash(SlotLayoutAccessors.readLongField(data, layout, StructuralField.HASH));
-        node.setName(EMPTY_QNM);
-        yield node;
-      }
-      case PROCESSING_INSTRUCTION -> {
-        final PINode node = new PINode(nodeKey, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, new byte[0], false,
-            hashFunction, deweyIdBytes, EMPTY_QNM);
-        node.setParentKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.PARENT_KEY));
-        node.setRightSiblingKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.RIGHT_SIBLING_KEY));
-        node.setLeftSiblingKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.LEFT_SIBLING_KEY));
-        node.setFirstChildKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.FIRST_CHILD_KEY));
-        node.setLastChildKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.LAST_CHILD_KEY));
-        node.setPathNodeKey(SlotLayoutAccessors.readLongField(data, layout, StructuralField.PATH_NODE_KEY));
-        node.setPrefixKey(SlotLayoutAccessors.readIntField(data, layout, StructuralField.PREFIX_KEY));
-        node.setLocalNameKey(SlotLayoutAccessors.readIntField(data, layout, StructuralField.LOCAL_NAME_KEY));
-        node.setURIKey(SlotLayoutAccessors.readIntField(data, layout, StructuralField.URI_KEY));
-        node.setPreviousRevision(SlotLayoutAccessors.readIntField(data, layout, StructuralField.PREVIOUS_REVISION));
-        node.setLastModifiedRevision(
-            SlotLayoutAccessors.readIntField(data, layout, StructuralField.LAST_MODIFIED_REVISION));
-        node.setChildCount(SlotLayoutAccessors.readLongField(data, layout, StructuralField.CHILD_COUNT));
-        node.setDescendantCount(SlotLayoutAccessors.readLongField(data, layout, StructuralField.DESCENDANT_COUNT));
-        // setRawValue BEFORE setHash — setRawValue resets hash to 0
-        readInlineXmlValuePayload(node, data, layout, 0);
-        node.setHash(SlotLayoutAccessors.readLongField(data, layout, StructuralField.HASH));
-        node.setName(EMPTY_QNM);
-        yield node;
-      }
-      default -> null;
-    };
-  }
-
-  /**
-   * Read inline string payload from the fixed-slot data and set it on the StringNode.
-   */
-  private static void readInlineStringPayload(final StringNode node, final MemorySegment data,
-      final NodeKindLayout layout, final int payloadRefIndex) {
-    final long pointer = SlotLayoutAccessors.readPayloadPointer(data, layout, payloadRefIndex);
-    final int length = SlotLayoutAccessors.readPayloadLength(data, layout, payloadRefIndex);
-    final int flags = SlotLayoutAccessors.readPayloadFlags(data, layout, payloadRefIndex);
-    final boolean isCompressed = (flags & 1) != 0;
-
-    final byte[] payloadBytes;
-    if (length > 0) {
-      payloadBytes = new byte[length];
-      MemorySegment.copy(data, pointer, MemorySegment.ofArray(payloadBytes), 0, length);
-    } else {
-      payloadBytes = new byte[0];
-    }
-    node.setRawValue(payloadBytes, isCompressed, null);
-  }
-
-  /**
-   * Read inline string payload from the fixed-slot data and set it on the ObjectStringNode.
-   */
-  private static void readInlineObjectStringPayload(final ObjectStringNode node, final MemorySegment data,
-      final NodeKindLayout layout, final int payloadRefIndex) {
-    final long pointer = SlotLayoutAccessors.readPayloadPointer(data, layout, payloadRefIndex);
-    final int length = SlotLayoutAccessors.readPayloadLength(data, layout, payloadRefIndex);
-    final int flags = SlotLayoutAccessors.readPayloadFlags(data, layout, payloadRefIndex);
-    final boolean isCompressed = (flags & 1) != 0;
-
-    final byte[] payloadBytes;
-    if (length > 0) {
-      payloadBytes = new byte[length];
-      MemorySegment.copy(data, pointer, MemorySegment.ofArray(payloadBytes), 0, length);
-    } else {
-      payloadBytes = new byte[0];
-    }
-    node.setRawValue(payloadBytes, isCompressed, null);
-  }
-
-  /**
-   * Read inline number payload from the fixed-slot data and set it on the NumberNode.
-   */
-  private static void readInlineNumberPayload(final NumberNode node, final MemorySegment data,
-      final NodeKindLayout layout, final int payloadRefIndex) {
-    final long pointer = SlotLayoutAccessors.readPayloadPointer(data, layout, payloadRefIndex);
-    final int length = SlotLayoutAccessors.readPayloadLength(data, layout, payloadRefIndex);
-
-    if (length > 0) {
-      final MemorySegment payloadSlice = data.asSlice(pointer, length);
-      final MemorySegmentBytesIn bytesIn = new MemorySegmentBytesIn(payloadSlice);
-      final Number value = NodeKind.deserializeNumber(bytesIn);
-      node.setValue(value);
-    } else {
-      node.setValue(0);
-    }
-  }
-
-  /**
-   * Read inline number payload from the fixed-slot data and set it on the ObjectNumberNode.
-   */
-  private static void readInlineNumberPayloadForObject(final ObjectNumberNode node, final MemorySegment data,
-      final NodeKindLayout layout, final int payloadRefIndex) {
-    final long pointer = SlotLayoutAccessors.readPayloadPointer(data, layout, payloadRefIndex);
-    final int length = SlotLayoutAccessors.readPayloadLength(data, layout, payloadRefIndex);
-
-    if (length > 0) {
-      final MemorySegment payloadSlice = data.asSlice(pointer, length);
-      final MemorySegmentBytesIn bytesIn = new MemorySegmentBytesIn(payloadSlice);
-      final Number value = NodeKind.deserializeNumber(bytesIn);
-      node.setValue(value);
-    } else {
-      node.setValue(0);
-    }
-  }
-
-  /**
-   * Read inline vector payload (attribute keys or namespace keys) from fixed-slot data and populate
-   * the ElementNode's lists.
-   *
-   * 

-   * Each vector entry is stored as an uncompressed 8-byte long in the inline payload area. The count
-   * is derived from {@code length / Long.BYTES}.
-   * 

-   *
-   * 

-   * This overload uses zero-based addressing (for slices or materialize cold path).
-   * 

-   *
-   * @param node the ElementNode to populate
-   * @param data fixed-slot bytes
-   * @param layout the layout descriptor
-   * @param payloadRefIndex 0 for attributes, 1 for namespaces
-   * @param isAttributes true to populate attribute keys, false for namespace keys
-   */
-  public static void readInlineVectorPayload(final ElementNode node, final MemorySegment data,
-      final NodeKindLayout layout, final int payloadRefIndex, final boolean isAttributes) {
-    readInlineVectorPayload(node, data, 0L, layout, payloadRefIndex, isAttributes);
-  }
-
-  /**
-   * Read inline vector payload with explicit base offset (avoids asSlice allocation).
-   *
-   * @param node the ElementNode to populate
-   * @param data the backing MemorySegment
-   * @param dataOffset absolute byte offset where slot data begins
-   * @param layout the layout descriptor
-   * @param payloadRefIndex 0 for attributes, 1 for namespaces
-   * @param isAttributes true to populate attribute keys, false for namespace keys
-   */
-  public static void readInlineVectorPayload(final ElementNode node, final MemorySegment data, final long dataOffset,
-      final NodeKindLayout layout, final int payloadRefIndex, final boolean isAttributes) {
-    final long pointer = SlotLayoutAccessors.readPayloadPointer(data, dataOffset, layout, payloadRefIndex);
-    final int length = SlotLayoutAccessors.readPayloadLength(data, dataOffset, layout, payloadRefIndex);
-    final int count = length / Long.BYTES;
-    if (isAttributes) {
-      node.clearAttributeKeys();
-      for (int i = 0; i < count; i++) {
-        node.insertAttribute(data.get(ValueLayout.JAVA_LONG_UNALIGNED, dataOffset + pointer + (long) i * Long.BYTES));
-      }
-    } else {
-      node.clearNamespaceKeys();
-      for (int i = 0; i < count; i++) {
-        node.insertNamespace(data.get(ValueLayout.JAVA_LONG_UNALIGNED, dataOffset + pointer + (long) i * Long.BYTES));
-      }
-    }
-  }
-
-  /**
-   * Read inline value payload from the fixed-slot data and set it on an XML ValueNode. Handles
-   * TextNode, CommentNode, PINode, and AttributeNode. If the compressed flag is set, the node's
-   * compressed state is updated accordingly.
-   */
-  private static void readInlineXmlValuePayload(final ValueNode node, final MemorySegment data,
-      final NodeKindLayout layout, final int payloadRefIndex) {
-    final long pointer = SlotLayoutAccessors.readPayloadPointer(data, layout, payloadRefIndex);
-    final int length = SlotLayoutAccessors.readPayloadLength(data, layout, payloadRefIndex);
-    final int flags = SlotLayoutAccessors.readPayloadFlags(data, layout, payloadRefIndex);
-    final boolean isCompressed = (flags & 1) != 0;
-
-    final byte[] payloadBytes;
-    if (length > 0) {
-      payloadBytes = new byte[length];
-      MemorySegment.copy(data, pointer, MemorySegment.ofArray(payloadBytes), 0, length);
-    } else {
-      payloadBytes = new byte[0];
-    }
-    node.setRawValue(payloadBytes);
-    if (isCompressed) {
-      if (node instanceof TextNode tn) {
-        tn.setCompressed(true);
-      } else if (node instanceof CommentNode cn) {
-        cn.setCompressed(true);
-      } else if (node instanceof PINode pi) {
-        pi.setCompressed(true);
-      }
-    }
-  }
-
-}
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/layout/FixedSlotRecordProjector.java b/bundles/sirix-core/src/main/java/io/sirix/node/layout/FixedSlotRecordProjector.java
deleted file mode 100644
index 530c34297..000000000
--- a/bundles/sirix-core/src/main/java/io/sirix/node/layout/FixedSlotRecordProjector.java
+++ /dev/null
@@ -1,469 +0,0 @@
-package io.sirix.node.layout;
-
-import io.sirix.node.NodeKind;
-import io.sirix.node.MemorySegmentBytesOut;
-import io.sirix.node.interfaces.BooleanValueNode;
-import io.sirix.node.interfaces.DataRecord;
-import io.sirix.node.interfaces.NameNode;
-import io.sirix.node.interfaces.NumericValueNode;
-import io.sirix.node.interfaces.StructNode;
-import io.sirix.node.interfaces.immutable.ImmutableNode;
-import io.sirix.node.json.ObjectKeyNode;
-import io.sirix.node.json.ObjectStringNode;
-import io.sirix.node.json.StringNode;
-import io.sirix.node.xml.AttributeNode;
-import io.sirix.node.xml.CommentNode;
-import io.sirix.node.xml.ElementNode;
-import io.sirix.node.xml.PINode;
-import io.sirix.node.xml.TextNode;
-
-import java.lang.foreign.MemorySegment;
-import java.lang.foreign.ValueLayout;
-import java.util.Objects;
-
-/**
- * Projects record structural metadata into a fixed-slot memory layout.
- *
- * 

- * The projector writes fixed-width structural fields directly, fills payload reference metadata,
- * and writes inline payload bytes for VALUE_BLOB payloads (strings, numbers).
- */
-public final class FixedSlotRecordProjector {
-
-  /** Unaligned long layout for reading/writing vector entries in inline payload. */
-  private static final ValueLayout.OfLong LONG_UNALIGNED = ValueLayout.JAVA_LONG_UNALIGNED;
-
-  /** Pre-zeroed buffer used to clear header bytes without allocating an asSlice(). */
-  private static final MemorySegment ZERO_BUFFER = MemorySegment.ofArray(new byte[512]);
-
-  /** Thread-local buffer for serializing number values inline. */
-  private static final ThreadLocal NUMBER_BUFFER =
-      ThreadLocal.withInitial(() -> new MemorySegmentBytesOut(32));
-
-  private FixedSlotRecordProjector() {}
-
-  /**
-   * Check whether all payload refs in the layout are supported for inline projection. Supported
-   * kinds: VALUE_BLOB, ATTRIBUTE_VECTOR, NAMESPACE_VECTOR.
-   *
-   * @param layout fixed-slot layout descriptor
-   * @return {@code true} if all payload refs are supported or there are no payload refs
-   */
-  public static boolean hasSupportedPayloads(final NodeKindLayout layout) {
-    for (int i = 0, refs = layout.payloadRefCount(); i < refs; i++) {
-      final PayloadRefKind kind = layout.payloadRef(i).kind();
-      if (kind != PayloadRefKind.VALUE_BLOB && kind != PayloadRefKind.ATTRIBUTE_VECTOR
-          && kind != PayloadRefKind.NAMESPACE_VECTOR) {
-        return false;
-      }
-    }
-    return true;
-  }
-
-  /**
-   * Compute the inline payload byte length for a record projected into the given layout.
-   *
-   * @param record the data record
-   * @param layout the layout descriptor
-   * @return total inline payload bytes, or {@code -1} if the record cannot be projected
-   */
-  public static int computeInlinePayloadLength(final DataRecord record, final NodeKindLayout layout) {
-    int total = 0;
-    for (int i = 0, refs = layout.payloadRefCount(); i < refs; i++) {
-      final PayloadRef payloadRef = layout.payloadRef(i);
-      final PayloadRefKind kind = payloadRef.kind();
-      if (kind == PayloadRefKind.VALUE_BLOB) {
-        final int length = getValueBlobLength(record);
-        if (length < 0) {
-          return -1;
-        }
-        total += length;
-      } else if (kind == PayloadRefKind.ATTRIBUTE_VECTOR || kind == PayloadRefKind.NAMESPACE_VECTOR) {
-        final int length = getVectorPayloadLength(record, kind);
-        if (length < 0) {
-          return -1;
-        }
-        total += length;
-      } else {
-        return -1;
-      }
-    }
-    return total;
-  }
-
-  /**
-   * Project a record into the given fixed-slot target at the specified base offset.
-   *
-   * 

-   * For payload-bearing nodes (strings, numbers), the target area starting at {@code baseOffset} must
-   * be sized to include both the fixed-slot header and inline payload bytes. The payload bytes are
-   * written immediately after the header, and the PayloadRef metadata in the header stores the offset
-   * (relative to slot data start) and length.
-   *
-   * @param record record to project
-   * @param layout fixed-slot layout descriptor
-   * @param targetSlot target memory (may be the full slotMemory)
-   * @param baseOffset absolute byte offset where the slot data begins
-   * @return {@code true} if projection succeeded, {@code false} if the record cannot be projected
-   */
-  public static boolean project(final DataRecord record, final NodeKindLayout layout, final MemorySegment targetSlot,
-      final long baseOffset) {
-    Objects.requireNonNull(record, "record must not be null");
-    Objects.requireNonNull(layout, "layout must not be null");
-    Objects.requireNonNull(targetSlot, "targetSlot must not be null");
-
-    if (!layout.isFixedSlotSupported()) {
-      return false;
-    }
-
-    // Only supported payload kinds are allowed for inline projection.
-    if (!hasSupportedPayloads(layout)) {
-      return false;
-    }
-
-    final int headerSize = layout.fixedSlotSizeInBytes();
-    if (targetSlot.byteSize() - baseOffset < headerSize) {
-      throw new IllegalArgumentException(
-          "target slot too small: available=" + (targetSlot.byteSize() - baseOffset) + " < " + headerSize);
-    }
-
-    // Clear the header portion using bulk copy from pre-zeroed buffer (avoids asSlice allocation).
-    MemorySegment.copy(ZERO_BUFFER, 0, targetSlot, baseOffset, headerSize);
-
-    final ImmutableNode immutableNode = record instanceof ImmutableNode node
-        ? node
-        : null;
-    final StructNode structNode = record instanceof StructNode node
-        ? node
-        : null;
-    final NameNode nameNode = record instanceof NameNode node
-        ? node
-        : null;
-    final BooleanValueNode booleanValueNode = record instanceof BooleanValueNode node
-        ? node
-        : null;
-    final ObjectKeyNode objectKeyNode = record instanceof ObjectKeyNode node
-        ? node
-        : null;
-
-    if (!writeCommonFields(record, immutableNode, targetSlot, baseOffset, layout)) {
-      return false;
-    }
-    if (!writeStructuralFields(structNode, targetSlot, baseOffset, layout)) {
-      return false;
-    }
-    if (!writeNameFields(nameNode, objectKeyNode, targetSlot, baseOffset, layout)) {
-      return false;
-    }
-    if (!writeBooleanField(booleanValueNode, targetSlot, baseOffset, layout)) {
-      return false;
-    }
-    if (!writeInlinePayloadRefs(record, targetSlot, baseOffset, layout)) {
-      return false;
-    }
-
-    return true;
-  }
-
-  private static boolean writeCommonFields(final DataRecord record, final ImmutableNode immutableNode,
-      final MemorySegment targetSlot, final long baseOffset, final NodeKindLayout layout) {
-    if (layout.hasField(StructuralField.PREVIOUS_REVISION)) {
-      SlotLayoutAccessors.writeIntField(targetSlot, baseOffset, layout, StructuralField.PREVIOUS_REVISION,
-          record.getPreviousRevisionNumber());
-    }
-    if (layout.hasField(StructuralField.LAST_MODIFIED_REVISION)) {
-      SlotLayoutAccessors.writeIntField(targetSlot, baseOffset, layout, StructuralField.LAST_MODIFIED_REVISION,
-          record.getLastModifiedRevisionNumber());
-    }
-    if (layout.hasField(StructuralField.PARENT_KEY)) {
-      if (immutableNode == null) {
-        return false;
-      }
-      SlotLayoutAccessors.writeLongField(targetSlot, baseOffset, layout, StructuralField.PARENT_KEY,
-          immutableNode.getParentKey());
-    }
-    if (layout.hasField(StructuralField.HASH)) {
-      if (immutableNode == null) {
-        return false;
-      }
-      SlotLayoutAccessors.writeLongField(targetSlot, baseOffset, layout, StructuralField.HASH, immutableNode.getHash());
-    }
-    return true;
-  }
-
-  private static boolean writeStructuralFields(final StructNode structNode, final MemorySegment targetSlot,
-      final long baseOffset, final NodeKindLayout layout) {
-    if (layout.hasField(StructuralField.RIGHT_SIBLING_KEY)) {
-      if (structNode == null) {
-        return false;
-      }
-      SlotLayoutAccessors.writeLongField(targetSlot, baseOffset, layout, StructuralField.RIGHT_SIBLING_KEY,
-          structNode.getRightSiblingKey());
-    }
-    if (layout.hasField(StructuralField.LEFT_SIBLING_KEY)) {
-      if (structNode == null) {
-        return false;
-      }
-      SlotLayoutAccessors.writeLongField(targetSlot, baseOffset, layout, StructuralField.LEFT_SIBLING_KEY,
-          structNode.getLeftSiblingKey());
-    }
-    if (layout.hasField(StructuralField.FIRST_CHILD_KEY)) {
-      if (structNode == null) {
-        return false;
-      }
-      SlotLayoutAccessors.writeLongField(targetSlot, baseOffset, layout, StructuralField.FIRST_CHILD_KEY,
-          structNode.getFirstChildKey());
-    }
-    if (layout.hasField(StructuralField.LAST_CHILD_KEY)) {
-      if (structNode == null) {
-        return false;
-      }
-      SlotLayoutAccessors.writeLongField(targetSlot, baseOffset, layout, StructuralField.LAST_CHILD_KEY,
-          structNode.getLastChildKey());
-    }
-    if (layout.hasField(StructuralField.CHILD_COUNT)) {
-      if (structNode == null) {
-        return false;
-      }
-      SlotLayoutAccessors.writeLongField(targetSlot, baseOffset, layout, StructuralField.CHILD_COUNT,
-          structNode.getChildCount());
-    }
-    if (layout.hasField(StructuralField.DESCENDANT_COUNT)) {
-      if (structNode == null) {
-        return false;
-      }
-      SlotLayoutAccessors.writeLongField(targetSlot, baseOffset, layout, StructuralField.DESCENDANT_COUNT,
-          structNode.getDescendantCount());
-    }
-    return true;
-  }
-
-  private static boolean writeNameFields(final NameNode nameNode, final ObjectKeyNode objectKeyNode,
-      final MemorySegment targetSlot, final long baseOffset, final NodeKindLayout layout) {
-    if (layout.hasField(StructuralField.PATH_NODE_KEY)) {
-      if (nameNode == null) {
-        return false;
-      }
-      SlotLayoutAccessors.writeLongField(targetSlot, baseOffset, layout, StructuralField.PATH_NODE_KEY,
-          nameNode.getPathNodeKey());
-    }
-    if (layout.hasField(StructuralField.PREFIX_KEY)) {
-      if (nameNode == null) {
-        return false;
-      }
-      SlotLayoutAccessors.writeIntField(targetSlot, baseOffset, layout, StructuralField.PREFIX_KEY,
-          nameNode.getPrefixKey());
-    }
-    if (layout.hasField(StructuralField.LOCAL_NAME_KEY)) {
-      if (nameNode == null) {
-        return false;
-      }
-      SlotLayoutAccessors.writeIntField(targetSlot, baseOffset, layout, StructuralField.LOCAL_NAME_KEY,
-          nameNode.getLocalNameKey());
-    }
-    if (layout.hasField(StructuralField.URI_KEY)) {
-      if (nameNode == null) {
-        return false;
-      }
-      SlotLayoutAccessors.writeIntField(targetSlot, baseOffset, layout, StructuralField.URI_KEY, nameNode.getURIKey());
-    }
-    if (layout.hasField(StructuralField.NAME_KEY)) {
-      if (objectKeyNode == null) {
-        return false;
-      }
-      SlotLayoutAccessors.writeIntField(targetSlot, baseOffset, layout, StructuralField.NAME_KEY,
-          objectKeyNode.getNameKey());
-    }
-    return true;
-  }
-
-  private static boolean writeBooleanField(final BooleanValueNode booleanValueNode, final MemorySegment targetSlot,
-      final long baseOffset, final NodeKindLayout layout) {
-    if (layout.hasField(StructuralField.BOOLEAN_VALUE)) {
-      if (booleanValueNode == null) {
-        return false;
-      }
-      SlotLayoutAccessors.writeBooleanField(targetSlot, baseOffset, layout, StructuralField.BOOLEAN_VALUE,
-          booleanValueNode.getValue());
-    }
-    return true;
-  }
-
-  /**
-   * Write PayloadRef metadata and inline payload bytes. Supports VALUE_BLOB (strings, numbers),
-   * ATTRIBUTE_VECTOR, and NAMESPACE_VECTOR. The inline payload is written immediately after the
-   * fixed-slot header.
-   */
-  private static boolean writeInlinePayloadRefs(final DataRecord record, final MemorySegment targetSlot,
-      final long baseOffset, final NodeKindLayout layout) {
-    final int refs = layout.payloadRefCount();
-    if (refs == 0) {
-      return true;
-    }
-
-    // payloadOffset is relative to slot data start (i.e. starts at headerSize)
-    int payloadOffset = layout.fixedSlotSizeInBytes();
-
-    for (int i = 0; i < refs; i++) {
-      final PayloadRef payloadRef = layout.payloadRef(i);
-      final PayloadRefKind refKind = payloadRef.kind();
-
-      if (refKind == PayloadRefKind.ATTRIBUTE_VECTOR) {
-        if (!(record instanceof ElementNode element)) {
-          return false;
-        }
-        final int count = element.getAttributeCount();
-        final int length = count * Long.BYTES;
-        SlotLayoutAccessors.writePayloadRef(targetSlot, baseOffset, layout, i, payloadOffset, length, 0);
-        for (int j = 0; j < count; j++) {
-          targetSlot.set(LONG_UNALIGNED, baseOffset + payloadOffset, element.getAttributeKey(j));
-          payloadOffset += Long.BYTES;
-        }
-        continue;
-      } else if (refKind == PayloadRefKind.NAMESPACE_VECTOR) {
-        if (!(record instanceof ElementNode element)) {
-          return false;
-        }
-        final int count = element.getNamespaceCount();
-        final int length = count * Long.BYTES;
-        SlotLayoutAccessors.writePayloadRef(targetSlot, baseOffset, layout, i, payloadOffset, length, 0);
-        for (int j = 0; j < count; j++) {
-          targetSlot.set(LONG_UNALIGNED, baseOffset + payloadOffset, element.getNamespaceKey(j));
-          payloadOffset += Long.BYTES;
-        }
-        continue;
-      }
-
-      // VALUE_BLOB handling
-      if (refKind != PayloadRefKind.VALUE_BLOB) {
-        return false;
-      }
-
-      final byte[] payloadBytes;
-      final int flags;
-
-      if (record instanceof StringNode sn) {
-        payloadBytes = sn.getRawValueWithoutDecompression();
-        flags = sn.isCompressed()
-            ? 1
-            : 0;
-      } else if (record instanceof ObjectStringNode osn) {
-        payloadBytes = osn.getRawValueWithoutDecompression();
-        flags = osn.isCompressed()
-            ? 1
-            : 0;
-      } else if (record instanceof TextNode tn) {
-        payloadBytes = tn.getRawValueWithoutDecompression();
-        flags = tn.isCompressed()
-            ? 1
-            : 0;
-      } else if (record instanceof CommentNode cn) {
-        payloadBytes = cn.getRawValueWithoutDecompression();
-        flags = cn.isCompressed()
-            ? 1
-            : 0;
-      } else if (record instanceof PINode pi) {
-        payloadBytes = pi.getRawValueWithoutDecompression();
-        flags = pi.isCompressed()
-            ? 1
-            : 0;
-      } else if (record instanceof AttributeNode an) {
-        payloadBytes = an.getRawValueWithoutDecompression();
-        flags = 0; // attributes never compressed
-      } else if (record instanceof NumericValueNode nn) {
-        final MemorySegmentBytesOut buf = NUMBER_BUFFER.get();
-        buf.clear();
-        NodeKind.serializeNumber(nn.getValue(), buf);
-        final MemorySegment serialized = buf.getDestination();
-        final int numLen = (int) serialized.byteSize();
-        SlotLayoutAccessors.writePayloadRef(targetSlot, baseOffset, layout, i, payloadOffset, numLen, 0);
-        if (numLen > 0) {
-          MemorySegment.copy(serialized, 0, targetSlot, baseOffset + payloadOffset, numLen);
-        }
-        payloadOffset += numLen;
-        continue;
-      } else {
-        return false;
-      }
-
-      final int length = payloadBytes != null
-          ? payloadBytes.length
-          : 0;
-      SlotLayoutAccessors.writePayloadRef(targetSlot, baseOffset, layout, i, payloadOffset, length, flags);
-      if (length > 0) {
-        MemorySegment.copy(MemorySegment.ofArray(payloadBytes), 0, targetSlot, baseOffset + payloadOffset, length);
-      }
-      payloadOffset += length;
-    }
-
-    return true;
-  }
-
-  /**
-   * Get the inline payload byte length for a VALUE_BLOB from the given record.
-   *
-   * @return byte length, or {@code -1} if the record type is unsupported
-   */
-  private static int getValueBlobLength(final DataRecord record) {
-    if (record instanceof StringNode sn) {
-      final byte[] raw = sn.getRawValueWithoutDecompression();
-      return raw != null
-          ? raw.length
-          : 0;
-    }
-    if (record instanceof ObjectStringNode osn) {
-      final byte[] raw = osn.getRawValueWithoutDecompression();
-      return raw != null
-          ? raw.length
-          : 0;
-    }
-    if (record instanceof TextNode tn) {
-      final byte[] raw = tn.getRawValueWithoutDecompression();
-      return raw != null
-          ? raw.length
-          : 0;
-    }
-    if (record instanceof CommentNode cn) {
-      final byte[] raw = cn.getRawValueWithoutDecompression();
-      return raw != null
-          ? raw.length
-          : 0;
-    }
-    if (record instanceof PINode pi) {
-      final byte[] raw = pi.getRawValueWithoutDecompression();
-      return raw != null
-          ? raw.length
-          : 0;
-    }
-    if (record instanceof AttributeNode an) {
-      final byte[] raw = an.getRawValueWithoutDecompression();
-      return raw != null
-          ? raw.length
-          : 0;
-    }
-    if (record instanceof NumericValueNode nn) {
-      final MemorySegmentBytesOut buf = NUMBER_BUFFER.get();
-      buf.clear();
-      NodeKind.serializeNumber(nn.getValue(), buf);
-      return (int) buf.getDestination().byteSize();
-    }
-    return -1;
-  }
-
-  /**
-   * Get the inline payload byte length for an ATTRIBUTE_VECTOR or NAMESPACE_VECTOR.
-   *
-   * @return byte length (count * 8), or {@code -1} if the record type is unsupported
-   */
-  private static int getVectorPayloadLength(final DataRecord record, final PayloadRefKind kind) {
-    if (!(record instanceof ElementNode element)) {
-      return -1;
-    }
-    if (kind == PayloadRefKind.ATTRIBUTE_VECTOR) {
-      return element.getAttributeCount() * Long.BYTES;
-    } else if (kind == PayloadRefKind.NAMESPACE_VECTOR) {
-      return element.getNamespaceCount() * Long.BYTES;
-    }
-    return -1;
-  }
-}
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/layout/FixedToCompactTransformer.java b/bundles/sirix-core/src/main/java/io/sirix/node/layout/FixedToCompactTransformer.java
deleted file mode 100644
index f1900147b..000000000
--- a/bundles/sirix-core/src/main/java/io/sirix/node/layout/FixedToCompactTransformer.java
+++ /dev/null
@@ -1,628 +0,0 @@
-package io.sirix.node.layout;
-
-import io.sirix.access.ResourceConfiguration;
-import io.sirix.access.trx.node.HashType;
-import io.sirix.node.BytesOut;
-import io.sirix.node.DeltaVarIntCodec;
-import io.sirix.node.NodeKind;
-
-import java.lang.foreign.MemorySegment;
-import java.lang.foreign.ValueLayout;
-
-/**
- * Zero-allocation byte-level transformer from fixed-slot format to compact (delta-varint) format.
- *
- * 

- * Instead of materializing a DataRecord Java object and re-serializing it, this class reads
- * fixed-width fields at known offsets and writes the compact encoding directly. The output is
- * byte-identical to
- * {@code NodeKind.serialize(sink, FixedSlotRecordMaterializer.materialize(...), config)}.
- *
- * 

- * All field offsets are pre-computed as {@code static final} constants from {@link NodeKindLayouts}
- * at class-load time, so the JIT treats them as compile-time constants.
- *
- * 

- * The {@code baseOffset} parameter allows reading from a full page {@link MemorySegment} without
- * creating an {@code asSlice()} wrapper, eliminating one heap allocation per slot on the commit path.
- */
-public final class FixedToCompactTransformer {
-
-  private static final ValueLayout.OfLong JAVA_LONG_UNALIGNED = ValueLayout.JAVA_LONG.withByteAlignment(1);
-  private static final ValueLayout.OfInt JAVA_INT_UNALIGNED = ValueLayout.JAVA_INT.withByteAlignment(1);
-
-  // ──────────────────────── JSON OBJECT ────────────────────────
-  private static final NodeKindLayout L_OBJ = NodeKindLayouts.layoutFor(NodeKind.OBJECT);
-  private static final int OBJ_PARENT = L_OBJ.offsetOfOrMinusOne(StructuralField.PARENT_KEY);
-  private static final int OBJ_RSIB = L_OBJ.offsetOfOrMinusOne(StructuralField.RIGHT_SIBLING_KEY);
-  private static final int OBJ_LSIB = L_OBJ.offsetOfOrMinusOne(StructuralField.LEFT_SIBLING_KEY);
-  private static final int OBJ_FCHILD = L_OBJ.offsetOfOrMinusOne(StructuralField.FIRST_CHILD_KEY);
-  private static final int OBJ_LCHILD = L_OBJ.offsetOfOrMinusOne(StructuralField.LAST_CHILD_KEY);
-  private static final int OBJ_PREV_REV = L_OBJ.offsetOfOrMinusOne(StructuralField.PREVIOUS_REVISION);
-  private static final int OBJ_LAST_MOD = L_OBJ.offsetOfOrMinusOne(StructuralField.LAST_MODIFIED_REVISION);
-  private static final int OBJ_HASH = L_OBJ.offsetOfOrMinusOne(StructuralField.HASH);
-  private static final int OBJ_CHILD_CNT = L_OBJ.offsetOfOrMinusOne(StructuralField.CHILD_COUNT);
-  private static final int OBJ_DESC_CNT = L_OBJ.offsetOfOrMinusOne(StructuralField.DESCENDANT_COUNT);
-
-  // ──────────────────────── JSON ARRAY ────────────────────────
-  private static final NodeKindLayout L_ARR = NodeKindLayouts.layoutFor(NodeKind.ARRAY);
-  private static final int ARR_PARENT = L_ARR.offsetOfOrMinusOne(StructuralField.PARENT_KEY);
-  private static final int ARR_RSIB = L_ARR.offsetOfOrMinusOne(StructuralField.RIGHT_SIBLING_KEY);
-  private static final int ARR_LSIB = L_ARR.offsetOfOrMinusOne(StructuralField.LEFT_SIBLING_KEY);
-  private static final int ARR_FCHILD = L_ARR.offsetOfOrMinusOne(StructuralField.FIRST_CHILD_KEY);
-  private static final int ARR_LCHILD = L_ARR.offsetOfOrMinusOne(StructuralField.LAST_CHILD_KEY);
-  private static final int ARR_PATH = L_ARR.offsetOfOrMinusOne(StructuralField.PATH_NODE_KEY);
-  private static final int ARR_PREV_REV = L_ARR.offsetOfOrMinusOne(StructuralField.PREVIOUS_REVISION);
-  private static final int ARR_LAST_MOD = L_ARR.offsetOfOrMinusOne(StructuralField.LAST_MODIFIED_REVISION);
-  private static final int ARR_HASH = L_ARR.offsetOfOrMinusOne(StructuralField.HASH);
-  private static final int ARR_CHILD_CNT = L_ARR.offsetOfOrMinusOne(StructuralField.CHILD_COUNT);
-  private static final int ARR_DESC_CNT = L_ARR.offsetOfOrMinusOne(StructuralField.DESCENDANT_COUNT);
-
-  // ──────────────────────── JSON OBJECT_KEY ────────────────────────
-  private static final NodeKindLayout L_OKEY = NodeKindLayouts.layoutFor(NodeKind.OBJECT_KEY);
-  private static final int OKEY_PARENT = L_OKEY.offsetOfOrMinusOne(StructuralField.PARENT_KEY);
-  private static final int OKEY_RSIB = L_OKEY.offsetOfOrMinusOne(StructuralField.RIGHT_SIBLING_KEY);
-  private static final int OKEY_LSIB = L_OKEY.offsetOfOrMinusOne(StructuralField.LEFT_SIBLING_KEY);
-  private static final int OKEY_FCHILD = L_OKEY.offsetOfOrMinusOne(StructuralField.FIRST_CHILD_KEY);
-  private static final int OKEY_PATH = L_OKEY.offsetOfOrMinusOne(StructuralField.PATH_NODE_KEY);
-  private static final int OKEY_NAME = L_OKEY.offsetOfOrMinusOne(StructuralField.NAME_KEY);
-  private static final int OKEY_PREV_REV = L_OKEY.offsetOfOrMinusOne(StructuralField.PREVIOUS_REVISION);
-  private static final int OKEY_LAST_MOD = L_OKEY.offsetOfOrMinusOne(StructuralField.LAST_MODIFIED_REVISION);
-  private static final int OKEY_HASH = L_OKEY.offsetOfOrMinusOne(StructuralField.HASH);
-  private static final int OKEY_DESC_CNT = L_OKEY.offsetOfOrMinusOne(StructuralField.DESCENDANT_COUNT);
-
-  // ──────────────────────── JSON STRING_VALUE ────────────────────────
-  private static final NodeKindLayout L_STR = NodeKindLayouts.layoutFor(NodeKind.STRING_VALUE);
-  private static final int STR_PARENT = L_STR.offsetOfOrMinusOne(StructuralField.PARENT_KEY);
-  private static final int STR_RSIB = L_STR.offsetOfOrMinusOne(StructuralField.RIGHT_SIBLING_KEY);
-  private static final int STR_LSIB = L_STR.offsetOfOrMinusOne(StructuralField.LEFT_SIBLING_KEY);
-  private static final int STR_PREV_REV = L_STR.offsetOfOrMinusOne(StructuralField.PREVIOUS_REVISION);
-  private static final int STR_LAST_MOD = L_STR.offsetOfOrMinusOne(StructuralField.LAST_MODIFIED_REVISION);
-  private static final int STR_HASH = L_STR.offsetOfOrMinusOne(StructuralField.HASH);
-  private static final int STR_PR0_PTR = L_STR.payloadRef(0).pointerOffset();
-  private static final int STR_PR0_LEN = L_STR.payloadRef(0).lengthOffset();
-  private static final int STR_PR0_FLAGS = L_STR.payloadRef(0).flagsOffset();
-
-  // ──────────────────────── JSON NUMBER_VALUE ────────────────────────
-  private static final NodeKindLayout L_NUM = NodeKindLayouts.layoutFor(NodeKind.NUMBER_VALUE);
-  private static final int NUM_PARENT = L_NUM.offsetOfOrMinusOne(StructuralField.PARENT_KEY);
-  private static final int NUM_RSIB = L_NUM.offsetOfOrMinusOne(StructuralField.RIGHT_SIBLING_KEY);
-  private static final int NUM_LSIB = L_NUM.offsetOfOrMinusOne(StructuralField.LEFT_SIBLING_KEY);
-  private static final int NUM_PREV_REV = L_NUM.offsetOfOrMinusOne(StructuralField.PREVIOUS_REVISION);
-  private static final int NUM_LAST_MOD = L_NUM.offsetOfOrMinusOne(StructuralField.LAST_MODIFIED_REVISION);
-  private static final int NUM_HASH = L_NUM.offsetOfOrMinusOne(StructuralField.HASH);
-  private static final int NUM_PR0_PTR = L_NUM.payloadRef(0).pointerOffset();
-  private static final int NUM_PR0_LEN = L_NUM.payloadRef(0).lengthOffset();
-
-  // ──────────────────────── JSON BOOLEAN_VALUE ────────────────────────
-  private static final NodeKindLayout L_BOOL = NodeKindLayouts.layoutFor(NodeKind.BOOLEAN_VALUE);
-  private static final int BOOL_PARENT = L_BOOL.offsetOfOrMinusOne(StructuralField.PARENT_KEY);
-  private static final int BOOL_RSIB = L_BOOL.offsetOfOrMinusOne(StructuralField.RIGHT_SIBLING_KEY);
-  private static final int BOOL_LSIB = L_BOOL.offsetOfOrMinusOne(StructuralField.LEFT_SIBLING_KEY);
-  private static final int BOOL_PREV_REV = L_BOOL.offsetOfOrMinusOne(StructuralField.PREVIOUS_REVISION);
-  private static final int BOOL_LAST_MOD = L_BOOL.offsetOfOrMinusOne(StructuralField.LAST_MODIFIED_REVISION);
-  private static final int BOOL_HASH = L_BOOL.offsetOfOrMinusOne(StructuralField.HASH);
-  private static final int BOOL_VAL = L_BOOL.offsetOfOrMinusOne(StructuralField.BOOLEAN_VALUE);
-
-  // ──────────────────────── JSON NULL_VALUE ────────────────────────
-  private static final NodeKindLayout L_NULL = NodeKindLayouts.layoutFor(NodeKind.NULL_VALUE);
-  private static final int NULL_PARENT = L_NULL.offsetOfOrMinusOne(StructuralField.PARENT_KEY);
-  private static final int NULL_RSIB = L_NULL.offsetOfOrMinusOne(StructuralField.RIGHT_SIBLING_KEY);
-  private static final int NULL_LSIB = L_NULL.offsetOfOrMinusOne(StructuralField.LEFT_SIBLING_KEY);
-  private static final int NULL_PREV_REV = L_NULL.offsetOfOrMinusOne(StructuralField.PREVIOUS_REVISION);
-  private static final int NULL_LAST_MOD = L_NULL.offsetOfOrMinusOne(StructuralField.LAST_MODIFIED_REVISION);
-  private static final int NULL_HASH = L_NULL.offsetOfOrMinusOne(StructuralField.HASH);
-
-  // ──────────────────────── JSON OBJECT_STRING_VALUE ────────────────────────
-  private static final NodeKindLayout L_OSTR = NodeKindLayouts.layoutFor(NodeKind.OBJECT_STRING_VALUE);
-  private static final int OSTR_PARENT = L_OSTR.offsetOfOrMinusOne(StructuralField.PARENT_KEY);
-  private static final int OSTR_PREV_REV = L_OSTR.offsetOfOrMinusOne(StructuralField.PREVIOUS_REVISION);
-  private static final int OSTR_LAST_MOD = L_OSTR.offsetOfOrMinusOne(StructuralField.LAST_MODIFIED_REVISION);
-  private static final int OSTR_HASH = L_OSTR.offsetOfOrMinusOne(StructuralField.HASH);
-  private static final int OSTR_PR0_PTR = L_OSTR.payloadRef(0).pointerOffset();
-  private static final int OSTR_PR0_LEN = L_OSTR.payloadRef(0).lengthOffset();
-  private static final int OSTR_PR0_FLAGS = L_OSTR.payloadRef(0).flagsOffset();
-
-  // ──────────────────────── JSON OBJECT_NUMBER_VALUE ────────────────────────
-  private static final NodeKindLayout L_ONUM = NodeKindLayouts.layoutFor(NodeKind.OBJECT_NUMBER_VALUE);
-  private static final int ONUM_PARENT = L_ONUM.offsetOfOrMinusOne(StructuralField.PARENT_KEY);
-  private static final int ONUM_PREV_REV = L_ONUM.offsetOfOrMinusOne(StructuralField.PREVIOUS_REVISION);
-  private static final int ONUM_LAST_MOD = L_ONUM.offsetOfOrMinusOne(StructuralField.LAST_MODIFIED_REVISION);
-  private static final int ONUM_HASH = L_ONUM.offsetOfOrMinusOne(StructuralField.HASH);
-  private static final int ONUM_PR0_PTR = L_ONUM.payloadRef(0).pointerOffset();
-  private static final int ONUM_PR0_LEN = L_ONUM.payloadRef(0).lengthOffset();
-
-  // ──────────────────────── JSON OBJECT_BOOLEAN_VALUE ────────────────────────
-  private static final NodeKindLayout L_OBOOL = NodeKindLayouts.layoutFor(NodeKind.OBJECT_BOOLEAN_VALUE);
-  private static final int OBOOL_PARENT = L_OBOOL.offsetOfOrMinusOne(StructuralField.PARENT_KEY);
-  private static final int OBOOL_PREV_REV = L_OBOOL.offsetOfOrMinusOne(StructuralField.PREVIOUS_REVISION);
-  private static final int OBOOL_LAST_MOD = L_OBOOL.offsetOfOrMinusOne(StructuralField.LAST_MODIFIED_REVISION);
-  private static final int OBOOL_HASH = L_OBOOL.offsetOfOrMinusOne(StructuralField.HASH);
-  private static final int OBOOL_VAL = L_OBOOL.offsetOfOrMinusOne(StructuralField.BOOLEAN_VALUE);
-
-  // ──────────────────────── JSON OBJECT_NULL_VALUE ────────────────────────
-  private static final NodeKindLayout L_ONULL = NodeKindLayouts.layoutFor(NodeKind.OBJECT_NULL_VALUE);
-  private static final int ONULL_PARENT = L_ONULL.offsetOfOrMinusOne(StructuralField.PARENT_KEY);
-  private static final int ONULL_PREV_REV = L_ONULL.offsetOfOrMinusOne(StructuralField.PREVIOUS_REVISION);
-  private static final int ONULL_LAST_MOD = L_ONULL.offsetOfOrMinusOne(StructuralField.LAST_MODIFIED_REVISION);
-  private static final int ONULL_HASH = L_ONULL.offsetOfOrMinusOne(StructuralField.HASH);
-
-  // ──────────────────────── JSON_DOCUMENT ────────────────────────
-  private static final NodeKindLayout L_JDOC = NodeKindLayouts.layoutFor(NodeKind.JSON_DOCUMENT);
-  private static final int JDOC_FCHILD = L_JDOC.offsetOfOrMinusOne(StructuralField.FIRST_CHILD_KEY);
-  private static final int JDOC_DESC_CNT = L_JDOC.offsetOfOrMinusOne(StructuralField.DESCENDANT_COUNT);
-
-  // ──────────────────────── XML_DOCUMENT ────────────────────────
-  private static final NodeKindLayout L_XDOC = NodeKindLayouts.layoutFor(NodeKind.XML_DOCUMENT);
-  private static final int XDOC_FCHILD = L_XDOC.offsetOfOrMinusOne(StructuralField.FIRST_CHILD_KEY);
-  private static final int XDOC_HASH = L_XDOC.offsetOfOrMinusOne(StructuralField.HASH);
-  private static final int XDOC_DESC_CNT = L_XDOC.offsetOfOrMinusOne(StructuralField.DESCENDANT_COUNT);
-
-  // ──────────────────────── XML ELEMENT ────────────────────────
-  private static final NodeKindLayout L_ELEM = NodeKindLayouts.layoutFor(NodeKind.ELEMENT);
-  private static final int ELEM_PARENT = L_ELEM.offsetOfOrMinusOne(StructuralField.PARENT_KEY);
-  private static final int ELEM_RSIB = L_ELEM.offsetOfOrMinusOne(StructuralField.RIGHT_SIBLING_KEY);
-  private static final int ELEM_LSIB = L_ELEM.offsetOfOrMinusOne(StructuralField.LEFT_SIBLING_KEY);
-  private static final int ELEM_FCHILD = L_ELEM.offsetOfOrMinusOne(StructuralField.FIRST_CHILD_KEY);
-  private static final int ELEM_LCHILD = L_ELEM.offsetOfOrMinusOne(StructuralField.LAST_CHILD_KEY);
-  private static final int ELEM_PATH = L_ELEM.offsetOfOrMinusOne(StructuralField.PATH_NODE_KEY);
-  private static final int ELEM_PREFIX = L_ELEM.offsetOfOrMinusOne(StructuralField.PREFIX_KEY);
-  private static final int ELEM_LNAME = L_ELEM.offsetOfOrMinusOne(StructuralField.LOCAL_NAME_KEY);
-  private static final int ELEM_URI = L_ELEM.offsetOfOrMinusOne(StructuralField.URI_KEY);
-  private static final int ELEM_PREV_REV = L_ELEM.offsetOfOrMinusOne(StructuralField.PREVIOUS_REVISION);
-  private static final int ELEM_LAST_MOD = L_ELEM.offsetOfOrMinusOne(StructuralField.LAST_MODIFIED_REVISION);
-  private static final int ELEM_HASH = L_ELEM.offsetOfOrMinusOne(StructuralField.HASH);
-  private static final int ELEM_CHILD_CNT = L_ELEM.offsetOfOrMinusOne(StructuralField.CHILD_COUNT);
-  private static final int ELEM_DESC_CNT = L_ELEM.offsetOfOrMinusOne(StructuralField.DESCENDANT_COUNT);
-  private static final int ELEM_ATTR_PR_PTR = L_ELEM.payloadRef(0).pointerOffset();
-  private static final int ELEM_ATTR_PR_LEN = L_ELEM.payloadRef(0).lengthOffset();
-  private static final int ELEM_NS_PR_PTR = L_ELEM.payloadRef(1).pointerOffset();
-  private static final int ELEM_NS_PR_LEN = L_ELEM.payloadRef(1).lengthOffset();
-
-  // ──────────────────────── XML ATTRIBUTE ────────────────────────
-  private static final NodeKindLayout L_ATTR = NodeKindLayouts.layoutFor(NodeKind.ATTRIBUTE);
-  private static final int ATTR_PARENT = L_ATTR.offsetOfOrMinusOne(StructuralField.PARENT_KEY);
-  private static final int ATTR_PATH = L_ATTR.offsetOfOrMinusOne(StructuralField.PATH_NODE_KEY);
-  private static final int ATTR_PREFIX = L_ATTR.offsetOfOrMinusOne(StructuralField.PREFIX_KEY);
-  private static final int ATTR_LNAME = L_ATTR.offsetOfOrMinusOne(StructuralField.LOCAL_NAME_KEY);
-  private static final int ATTR_URI = L_ATTR.offsetOfOrMinusOne(StructuralField.URI_KEY);
-  private static final int ATTR_PREV_REV = L_ATTR.offsetOfOrMinusOne(StructuralField.PREVIOUS_REVISION);
-  private static final int ATTR_LAST_MOD = L_ATTR.offsetOfOrMinusOne(StructuralField.LAST_MODIFIED_REVISION);
-  private static final int ATTR_PR0_PTR = L_ATTR.payloadRef(0).pointerOffset();
-  private static final int ATTR_PR0_LEN = L_ATTR.payloadRef(0).lengthOffset();
-
-  // ──────────────────────── XML NAMESPACE ────────────────────────
-  private static final NodeKindLayout L_NS = NodeKindLayouts.layoutFor(NodeKind.NAMESPACE);
-  private static final int NS_PARENT = L_NS.offsetOfOrMinusOne(StructuralField.PARENT_KEY);
-  private static final int NS_PATH = L_NS.offsetOfOrMinusOne(StructuralField.PATH_NODE_KEY);
-  private static final int NS_PREFIX = L_NS.offsetOfOrMinusOne(StructuralField.PREFIX_KEY);
-  private static final int NS_LNAME = L_NS.offsetOfOrMinusOne(StructuralField.LOCAL_NAME_KEY);
-  private static final int NS_URI = L_NS.offsetOfOrMinusOne(StructuralField.URI_KEY);
-  private static final int NS_PREV_REV = L_NS.offsetOfOrMinusOne(StructuralField.PREVIOUS_REVISION);
-  private static final int NS_LAST_MOD = L_NS.offsetOfOrMinusOne(StructuralField.LAST_MODIFIED_REVISION);
-
-  // ──────────────────────── XML TEXT ────────────────────────
-  private static final NodeKindLayout L_TEXT = NodeKindLayouts.layoutFor(NodeKind.TEXT);
-  private static final int TEXT_PARENT = L_TEXT.offsetOfOrMinusOne(StructuralField.PARENT_KEY);
-  private static final int TEXT_RSIB = L_TEXT.offsetOfOrMinusOne(StructuralField.RIGHT_SIBLING_KEY);
-  private static final int TEXT_LSIB = L_TEXT.offsetOfOrMinusOne(StructuralField.LEFT_SIBLING_KEY);
-  private static final int TEXT_PREV_REV = L_TEXT.offsetOfOrMinusOne(StructuralField.PREVIOUS_REVISION);
-  private static final int TEXT_LAST_MOD = L_TEXT.offsetOfOrMinusOne(StructuralField.LAST_MODIFIED_REVISION);
-  private static final int TEXT_PR0_PTR = L_TEXT.payloadRef(0).pointerOffset();
-  private static final int TEXT_PR0_LEN = L_TEXT.payloadRef(0).lengthOffset();
-  private static final int TEXT_PR0_FLAGS = L_TEXT.payloadRef(0).flagsOffset();
-
-  // ──────────────────────── XML COMMENT ────────────────────────
-  private static final NodeKindLayout L_CMT = NodeKindLayouts.layoutFor(NodeKind.COMMENT);
-  private static final int CMT_PARENT = L_CMT.offsetOfOrMinusOne(StructuralField.PARENT_KEY);
-  private static final int CMT_RSIB = L_CMT.offsetOfOrMinusOne(StructuralField.RIGHT_SIBLING_KEY);
-  private static final int CMT_LSIB = L_CMT.offsetOfOrMinusOne(StructuralField.LEFT_SIBLING_KEY);
-  private static final int CMT_PREV_REV = L_CMT.offsetOfOrMinusOne(StructuralField.PREVIOUS_REVISION);
-  private static final int CMT_LAST_MOD = L_CMT.offsetOfOrMinusOne(StructuralField.LAST_MODIFIED_REVISION);
-  private static final int CMT_PR0_PTR = L_CMT.payloadRef(0).pointerOffset();
-  private static final int CMT_PR0_LEN = L_CMT.payloadRef(0).lengthOffset();
-  private static final int CMT_PR0_FLAGS = L_CMT.payloadRef(0).flagsOffset();
-
-  // ──────────────────────── XML PROCESSING_INSTRUCTION ────────────────────────
-  private static final NodeKindLayout L_PI = NodeKindLayouts.layoutFor(NodeKind.PROCESSING_INSTRUCTION);
-  private static final int PI_PARENT = L_PI.offsetOfOrMinusOne(StructuralField.PARENT_KEY);
-  private static final int PI_RSIB = L_PI.offsetOfOrMinusOne(StructuralField.RIGHT_SIBLING_KEY);
-  private static final int PI_LSIB = L_PI.offsetOfOrMinusOne(StructuralField.LEFT_SIBLING_KEY);
-  private static final int PI_FCHILD = L_PI.offsetOfOrMinusOne(StructuralField.FIRST_CHILD_KEY);
-  private static final int PI_LCHILD = L_PI.offsetOfOrMinusOne(StructuralField.LAST_CHILD_KEY);
-  private static final int PI_PATH = L_PI.offsetOfOrMinusOne(StructuralField.PATH_NODE_KEY);
-  private static final int PI_PREFIX = L_PI.offsetOfOrMinusOne(StructuralField.PREFIX_KEY);
-  private static final int PI_LNAME = L_PI.offsetOfOrMinusOne(StructuralField.LOCAL_NAME_KEY);
-  private static final int PI_URI = L_PI.offsetOfOrMinusOne(StructuralField.URI_KEY);
-  private static final int PI_PREV_REV = L_PI.offsetOfOrMinusOne(StructuralField.PREVIOUS_REVISION);
-  private static final int PI_LAST_MOD = L_PI.offsetOfOrMinusOne(StructuralField.LAST_MODIFIED_REVISION);
-  private static final int PI_HASH = L_PI.offsetOfOrMinusOne(StructuralField.HASH);
-  private static final int PI_CHILD_CNT = L_PI.offsetOfOrMinusOne(StructuralField.CHILD_COUNT);
-  private static final int PI_DESC_CNT = L_PI.offsetOfOrMinusOne(StructuralField.DESCENDANT_COUNT);
-  private static final int PI_PR0_PTR = L_PI.payloadRef(0).pointerOffset();
-  private static final int PI_PR0_LEN = L_PI.payloadRef(0).lengthOffset();
-  private static final int PI_PR0_FLAGS = L_PI.payloadRef(0).flagsOffset();
-
-  private FixedToCompactTransformer() {}
-
-  /**
-   * Transform a fixed-slot record to compact format, writing the result (including the leading
-   * NodeKind id byte) into {@code sink}.
-   *
-   * 

-   * Reads from {@code memory} at {@code baseOffset + fieldOffset} for each field, eliminating
-   * the need to create an {@code asSlice()} wrapper per slot.
-   *
-   * @param nodeKind the kind of node stored in this slot
-   * @param nodeKey the absolute node key
-   * @param memory the page memory segment containing the fixed-slot bytes
-   * @param baseOffset byte offset within {@code memory} where the slot data starts
-   * @param config the resource configuration
-   * @param sink the output sink to write compact bytes into
-   */
-  public static void transform(final NodeKind nodeKind, final long nodeKey, final MemorySegment memory,
-      final long baseOffset, final ResourceConfiguration config, final BytesOut sink) {
-    sink.writeByte(nodeKind.getId());
-
-    switch (nodeKind) {
-      case OBJECT -> transformObject(nodeKey, memory, baseOffset, config, sink);
-      case ARRAY -> transformArray(nodeKey, memory, baseOffset, config, sink);
-      case OBJECT_KEY -> transformObjectKey(nodeKey, memory, baseOffset, config, sink);
-      case STRING_VALUE -> transformStringValue(nodeKey, memory, baseOffset, config, sink);
-      case NUMBER_VALUE -> transformNumberValue(nodeKey, memory, baseOffset, config, sink);
-      case BOOLEAN_VALUE -> transformBooleanValue(nodeKey, memory, baseOffset, config, sink);
-      case NULL_VALUE -> transformNullValue(nodeKey, memory, baseOffset, config, sink);
-      case OBJECT_STRING_VALUE -> transformObjectStringValue(nodeKey, memory, baseOffset, config, sink);
-      case OBJECT_NUMBER_VALUE -> transformObjectNumberValue(nodeKey, memory, baseOffset, config, sink);
-      case OBJECT_BOOLEAN_VALUE -> transformObjectBooleanValue(nodeKey, memory, baseOffset, config, sink);
-      case OBJECT_NULL_VALUE -> transformObjectNullValue(nodeKey, memory, baseOffset, config, sink);
-      case JSON_DOCUMENT -> transformJsonDocument(nodeKey, memory, baseOffset, sink);
-      case XML_DOCUMENT -> transformXmlDocument(nodeKey, memory, baseOffset, config, sink);
-      case ELEMENT -> transformElement(nodeKey, memory, baseOffset, config, sink);
-      case ATTRIBUTE -> transformAttribute(nodeKey, memory, baseOffset, sink);
-      case NAMESPACE -> transformNamespace(nodeKey, memory, baseOffset, sink);
-      case TEXT -> transformText(nodeKey, memory, baseOffset, sink);
-      case COMMENT -> transformComment(nodeKey, memory, baseOffset, sink);
-      case PROCESSING_INSTRUCTION -> transformProcessingInstruction(nodeKey, memory, baseOffset, config, sink);
-      default ->
-        throw new UnsupportedOperationException("FixedToCompactTransformer does not support node kind: " + nodeKind);
-    }
-  }
-
-  // ════════════════════════════ JSON STRUCTURAL ════════════════════════════
-
-  private static void transformObject(final long nodeKey, final MemorySegment m, final long b,
-      final ResourceConfiguration config, final BytesOut sink) {
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + OBJ_PARENT), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + OBJ_RSIB), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + OBJ_LSIB), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + OBJ_FCHILD), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + OBJ_LCHILD), nodeKey);
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + OBJ_PREV_REV));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + OBJ_LAST_MOD));
-    if (config.storeChildCount()) {
-      DeltaVarIntCodec.encodeSigned(sink, (int) m.get(JAVA_LONG_UNALIGNED, b + OBJ_CHILD_CNT));
-    }
-    if (config.hashType != HashType.NONE) {
-      sink.writeLong(m.get(JAVA_LONG_UNALIGNED, b + OBJ_HASH));
-      DeltaVarIntCodec.encodeSigned(sink, (int) m.get(JAVA_LONG_UNALIGNED, b + OBJ_DESC_CNT));
-    }
-  }
-
-  private static void transformArray(final long nodeKey, final MemorySegment m, final long b,
-      final ResourceConfiguration config, final BytesOut sink) {
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + ARR_PARENT), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + ARR_RSIB), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + ARR_LSIB), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + ARR_FCHILD), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + ARR_LCHILD), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + ARR_PATH), nodeKey);
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + ARR_PREV_REV));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + ARR_LAST_MOD));
-    if (config.storeChildCount()) {
-      DeltaVarIntCodec.encodeSigned(sink, (int) m.get(JAVA_LONG_UNALIGNED, b + ARR_CHILD_CNT));
-    }
-    if (config.hashType != HashType.NONE) {
-      sink.writeLong(m.get(JAVA_LONG_UNALIGNED, b + ARR_HASH));
-      DeltaVarIntCodec.encodeSigned(sink, (int) m.get(JAVA_LONG_UNALIGNED, b + ARR_DESC_CNT));
-    }
-  }
-
-  private static void transformObjectKey(final long nodeKey, final MemorySegment m, final long b,
-      final ResourceConfiguration config, final BytesOut sink) {
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + OKEY_PARENT), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + OKEY_RSIB), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + OKEY_LSIB), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + OKEY_FCHILD), nodeKey);
-    // LAST_CHILD_KEY is in the fixed layout but NOT written in compact format
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + OKEY_NAME));
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + OKEY_PATH), nodeKey);
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + OKEY_PREV_REV));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + OKEY_LAST_MOD));
-    if (config.hashType != HashType.NONE) {
-      sink.writeLong(m.get(JAVA_LONG_UNALIGNED, b + OKEY_HASH));
-      DeltaVarIntCodec.encodeSigned(sink, (int) m.get(JAVA_LONG_UNALIGNED, b + OKEY_DESC_CNT));
-    }
-  }
-
-  // ════════════════════════════ JSON VALUE (WITH SIBLINGS) ════════════════════════════
-
-  private static void transformStringValue(final long nodeKey, final MemorySegment m, final long b,
-      final ResourceConfiguration config, final BytesOut sink) {
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + STR_PARENT), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + STR_RSIB), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + STR_LSIB), nodeKey);
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + STR_PREV_REV));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + STR_LAST_MOD));
-    if (config.hashType != HashType.NONE) {
-      sink.writeLong(m.get(JAVA_LONG_UNALIGNED, b + STR_HASH));
-    }
-    final int flags = m.get(JAVA_INT_UNALIGNED, b + STR_PR0_FLAGS);
-    sink.writeByte((byte) (flags & 1));
-    final long pointer = m.get(JAVA_LONG_UNALIGNED, b + STR_PR0_PTR);
-    final int length = m.get(JAVA_INT_UNALIGNED, b + STR_PR0_LEN);
-    DeltaVarIntCodec.encodeSigned(sink, length);
-    if (length > 0) {
-      sink.writeSegment(m, b + pointer, length);
-    }
-  }
-
-  private static void transformNumberValue(final long nodeKey, final MemorySegment m, final long b,
-      final ResourceConfiguration config, final BytesOut sink) {
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + NUM_PARENT), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + NUM_RSIB), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + NUM_LSIB), nodeKey);
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + NUM_PREV_REV));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + NUM_LAST_MOD));
-    if (config.hashType != HashType.NONE) {
-      sink.writeLong(m.get(JAVA_LONG_UNALIGNED, b + NUM_HASH));
-    }
-    final long pointer = m.get(JAVA_LONG_UNALIGNED, b + NUM_PR0_PTR);
-    final int length = m.get(JAVA_INT_UNALIGNED, b + NUM_PR0_LEN);
-    if (length > 0) {
-      sink.writeSegment(m, b + pointer, length);
-    }
-  }
-
-  private static void transformBooleanValue(final long nodeKey, final MemorySegment m, final long b,
-      final ResourceConfiguration config, final BytesOut sink) {
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + BOOL_PARENT), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + BOOL_RSIB), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + BOOL_LSIB), nodeKey);
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + BOOL_PREV_REV));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + BOOL_LAST_MOD));
-    sink.writeBoolean(m.get(ValueLayout.JAVA_BYTE, b + BOOL_VAL) != 0);
-    if (config.hashType != HashType.NONE) {
-      sink.writeLong(m.get(JAVA_LONG_UNALIGNED, b + BOOL_HASH));
-    }
-  }
-
-  private static void transformNullValue(final long nodeKey, final MemorySegment m, final long b,
-      final ResourceConfiguration config, final BytesOut sink) {
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + NULL_PARENT), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + NULL_RSIB), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + NULL_LSIB), nodeKey);
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + NULL_PREV_REV));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + NULL_LAST_MOD));
-    if (config.hashType != HashType.NONE) {
-      sink.writeLong(m.get(JAVA_LONG_UNALIGNED, b + NULL_HASH));
-    }
-  }
-
-  // ════════════════════════════ JSON VALUE (OBJECT-PROPERTY, NO SIBLINGS) ════════════════════════════
-
-  private static void transformObjectStringValue(final long nodeKey, final MemorySegment m, final long b,
-      final ResourceConfiguration config, final BytesOut sink) {
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + OSTR_PARENT), nodeKey);
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + OSTR_PREV_REV));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + OSTR_LAST_MOD));
-    if (config.hashType != HashType.NONE) {
-      sink.writeLong(m.get(JAVA_LONG_UNALIGNED, b + OSTR_HASH));
-    }
-    final int flags = m.get(JAVA_INT_UNALIGNED, b + OSTR_PR0_FLAGS);
-    sink.writeByte((byte) (flags & 1));
-    final long pointer = m.get(JAVA_LONG_UNALIGNED, b + OSTR_PR0_PTR);
-    final int length = m.get(JAVA_INT_UNALIGNED, b + OSTR_PR0_LEN);
-    DeltaVarIntCodec.encodeSigned(sink, length);
-    if (length > 0) {
-      sink.writeSegment(m, b + pointer, length);
-    }
-  }
-
-  private static void transformObjectNumberValue(final long nodeKey, final MemorySegment m, final long b,
-      final ResourceConfiguration config, final BytesOut sink) {
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + ONUM_PARENT), nodeKey);
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + ONUM_PREV_REV));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + ONUM_LAST_MOD));
-    if (config.hashType != HashType.NONE) {
-      sink.writeLong(m.get(JAVA_LONG_UNALIGNED, b + ONUM_HASH));
-    }
-    final long pointer = m.get(JAVA_LONG_UNALIGNED, b + ONUM_PR0_PTR);
-    final int length = m.get(JAVA_INT_UNALIGNED, b + ONUM_PR0_LEN);
-    if (length > 0) {
-      sink.writeSegment(m, b + pointer, length);
-    }
-  }
-
-  private static void transformObjectBooleanValue(final long nodeKey, final MemorySegment m, final long b,
-      final ResourceConfiguration config, final BytesOut sink) {
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + OBOOL_PARENT), nodeKey);
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + OBOOL_PREV_REV));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + OBOOL_LAST_MOD));
-    sink.writeBoolean(m.get(ValueLayout.JAVA_BYTE, b + OBOOL_VAL) != 0);
-    if (config.hashType != HashType.NONE) {
-      sink.writeLong(m.get(JAVA_LONG_UNALIGNED, b + OBOOL_HASH));
-    }
-  }
-
-  private static void transformObjectNullValue(final long nodeKey, final MemorySegment m, final long b,
-      final ResourceConfiguration config, final BytesOut sink) {
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + ONULL_PARENT), nodeKey);
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + ONULL_PREV_REV));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + ONULL_LAST_MOD));
-    if (config.hashType != HashType.NONE) {
-      sink.writeLong(m.get(JAVA_LONG_UNALIGNED, b + ONULL_HASH));
-    }
-  }
-
-  // ════════════════════════════ JSON DOCUMENT ════════════════════════════
-
-  private static void transformJsonDocument(final long nodeKey, final MemorySegment m, final long b,
-      final BytesOut sink) {
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + JDOC_FCHILD), nodeKey);
-    DeltaVarIntCodec.encodeSignedLong(sink, m.get(JAVA_LONG_UNALIGNED, b + JDOC_DESC_CNT));
-  }
-
-  // ════════════════════════════ XML DOCUMENT ════════════════════════════
-
-  private static void transformXmlDocument(final long nodeKey, final MemorySegment m, final long b,
-      final ResourceConfiguration config, final BytesOut sink) {
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + XDOC_FCHILD), nodeKey);
-    if (config.hashType != HashType.NONE) {
-      sink.writeLong(m.get(JAVA_LONG_UNALIGNED, b + XDOC_HASH));
-      DeltaVarIntCodec.encodeSignedLong(sink, m.get(JAVA_LONG_UNALIGNED, b + XDOC_DESC_CNT));
-    }
-  }
-
-  // ════════════════════════════ XML ELEMENT ════════════════════════════
-
-  private static void transformElement(final long nodeKey, final MemorySegment m, final long b,
-      final ResourceConfiguration config, final BytesOut sink) {
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + ELEM_PARENT), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + ELEM_RSIB), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + ELEM_LSIB), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + ELEM_FCHILD), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + ELEM_LCHILD), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + ELEM_PATH), nodeKey);
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + ELEM_PREFIX));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + ELEM_LNAME));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + ELEM_URI));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + ELEM_PREV_REV));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + ELEM_LAST_MOD));
-    if (config.storeChildCount()) {
-      DeltaVarIntCodec.encodeSigned(sink, (int) m.get(JAVA_LONG_UNALIGNED, b + ELEM_CHILD_CNT));
-    }
-    if (config.hashType != HashType.NONE) {
-      sink.writeLong(m.get(JAVA_LONG_UNALIGNED, b + ELEM_HASH));
-      DeltaVarIntCodec.encodeSigned(sink, (int) m.get(JAVA_LONG_UNALIGNED, b + ELEM_DESC_CNT));
-    }
-    // Attribute keys vector
-    final long attrPointer = m.get(JAVA_LONG_UNALIGNED, b + ELEM_ATTR_PR_PTR);
-    final int attrLength = m.get(JAVA_INT_UNALIGNED, b + ELEM_ATTR_PR_LEN);
-    final int attrCount = attrLength / Long.BYTES;
-    DeltaVarIntCodec.encodeSigned(sink, attrCount);
-    for (int i = 0; i < attrCount; i++) {
-      DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + attrPointer + (long) i * Long.BYTES), nodeKey);
-    }
-    // Namespace keys vector
-    final long nsPointer = m.get(JAVA_LONG_UNALIGNED, b + ELEM_NS_PR_PTR);
-    final int nsLength = m.get(JAVA_INT_UNALIGNED, b + ELEM_NS_PR_LEN);
-    final int nsCount = nsLength / Long.BYTES;
-    DeltaVarIntCodec.encodeSigned(sink, nsCount);
-    for (int i = 0; i < nsCount; i++) {
-      DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + nsPointer + (long) i * Long.BYTES), nodeKey);
-    }
-  }
-
-  // ════════════════════════════ XML ATTRIBUTE ════════════════════════════
-
-  private static void transformAttribute(final long nodeKey, final MemorySegment m, final long b,
-      final BytesOut sink) {
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + ATTR_PARENT), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + ATTR_PATH), nodeKey);
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + ATTR_PREFIX));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + ATTR_LNAME));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + ATTR_URI));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + ATTR_PREV_REV));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + ATTR_LAST_MOD));
-    sink.writeByte((byte) 0);
-    final long pointer = m.get(JAVA_LONG_UNALIGNED, b + ATTR_PR0_PTR);
-    final int length = m.get(JAVA_INT_UNALIGNED, b + ATTR_PR0_LEN);
-    DeltaVarIntCodec.encodeSigned(sink, length);
-    if (length > 0) {
-      sink.writeSegment(m, b + pointer, length);
-    }
-  }
-
-  // ════════════════════════════ XML NAMESPACE ════════════════════════════
-
-  private static void transformNamespace(final long nodeKey, final MemorySegment m, final long b,
-      final BytesOut sink) {
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + NS_PARENT), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + NS_PATH), nodeKey);
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + NS_PREFIX));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + NS_LNAME));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + NS_URI));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + NS_PREV_REV));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + NS_LAST_MOD));
-  }
-
-  // ════════════════════════════ XML TEXT ════════════════════════════
-
-  private static void transformText(final long nodeKey, final MemorySegment m, final long b, final BytesOut sink) {
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + TEXT_PARENT), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + TEXT_RSIB), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + TEXT_LSIB), nodeKey);
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + TEXT_PREV_REV));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + TEXT_LAST_MOD));
-    final int flags = m.get(JAVA_INT_UNALIGNED, b + TEXT_PR0_FLAGS);
-    sink.writeByte((byte) (flags & 1));
-    final long pointer = m.get(JAVA_LONG_UNALIGNED, b + TEXT_PR0_PTR);
-    final int length = m.get(JAVA_INT_UNALIGNED, b + TEXT_PR0_LEN);
-    DeltaVarIntCodec.encodeSigned(sink, length);
-    if (length > 0) {
-      sink.writeSegment(m, b + pointer, length);
-    }
-  }
-
-  // ════════════════════════════ XML COMMENT ════════════════════════════
-
-  private static void transformComment(final long nodeKey, final MemorySegment m, final long b,
-      final BytesOut sink) {
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + CMT_PARENT), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + CMT_RSIB), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + CMT_LSIB), nodeKey);
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + CMT_PREV_REV));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + CMT_LAST_MOD));
-    final int flags = m.get(JAVA_INT_UNALIGNED, b + CMT_PR0_FLAGS);
-    sink.writeByte((byte) (flags & 1));
-    final long pointer = m.get(JAVA_LONG_UNALIGNED, b + CMT_PR0_PTR);
-    final int length = m.get(JAVA_INT_UNALIGNED, b + CMT_PR0_LEN);
-    DeltaVarIntCodec.encodeSigned(sink, length);
-    if (length > 0) {
-      sink.writeSegment(m, b + pointer, length);
-    }
-  }
-
-  // ════════════════════════════ XML PROCESSING_INSTRUCTION ════════════════════════════
-
-  private static void transformProcessingInstruction(final long nodeKey, final MemorySegment m, final long b,
-      final ResourceConfiguration config, final BytesOut sink) {
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + PI_PARENT), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + PI_RSIB), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + PI_LSIB), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + PI_FCHILD), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + PI_LCHILD), nodeKey);
-    DeltaVarIntCodec.encodeDelta(sink, m.get(JAVA_LONG_UNALIGNED, b + PI_PATH), nodeKey);
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + PI_PREFIX));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + PI_LNAME));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + PI_URI));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + PI_PREV_REV));
-    DeltaVarIntCodec.encodeSigned(sink, m.get(JAVA_INT_UNALIGNED, b + PI_LAST_MOD));
-    if (config.storeChildCount()) {
-      DeltaVarIntCodec.encodeSigned(sink, (int) m.get(JAVA_LONG_UNALIGNED, b + PI_CHILD_CNT));
-    }
-    if (config.hashType != HashType.NONE) {
-      sink.writeLong(m.get(JAVA_LONG_UNALIGNED, b + PI_HASH));
-      DeltaVarIntCodec.encodeSigned(sink, (int) m.get(JAVA_LONG_UNALIGNED, b + PI_DESC_CNT));
-    }
-    final int flags = m.get(JAVA_INT_UNALIGNED, b + PI_PR0_FLAGS);
-    sink.writeByte((byte) (flags & 1));
-    final long pointer = m.get(JAVA_LONG_UNALIGNED, b + PI_PR0_PTR);
-    final int length = m.get(JAVA_INT_UNALIGNED, b + PI_PR0_LEN);
-    DeltaVarIntCodec.encodeSigned(sink, length);
-    if (length > 0) {
-      sink.writeSegment(m, b + pointer, length);
-    }
-  }
-}
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/layout/NodeKindLayout.java b/bundles/sirix-core/src/main/java/io/sirix/node/layout/NodeKindLayout.java
deleted file mode 100644
index 4bf865624..000000000
--- a/bundles/sirix-core/src/main/java/io/sirix/node/layout/NodeKindLayout.java
+++ /dev/null
@@ -1,142 +0,0 @@
-package io.sirix.node.layout;
-
-import io.sirix.node.NodeKind;
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-import java.util.Objects;
-
-/**
- * Fixed-slot layout contract for a {@link NodeKind}.
- */
-public final class NodeKindLayout {
-  private static final int UNSUPPORTED_FIELD_OFFSET = -1;
-  private static final int FIELD_COUNT = StructuralField.values().length;
-
-  private final NodeKind nodeKind;
-  private final int fixedSlotSizeInBytes;
-  private final boolean fixedSlotSupported;
-  private final int[] offsets;
-  private final PayloadRef[] payloadRefs;
-  private final boolean hasSupportedPayloads;
-
-  private NodeKindLayout(final NodeKind nodeKind, final int fixedSlotSizeInBytes, final boolean fixedSlotSupported,
-      final int[] offsets, final PayloadRef[] payloadRefs) {
-    this.nodeKind = Objects.requireNonNull(nodeKind);
-    this.fixedSlotSizeInBytes = fixedSlotSizeInBytes;
-    this.fixedSlotSupported = fixedSlotSupported;
-    this.offsets = Objects.requireNonNull(offsets).clone();
-    this.payloadRefs = Objects.requireNonNull(payloadRefs).clone();
-    this.hasSupportedPayloads = computeHasSupportedPayloads(this.payloadRefs);
-  }
-
-  private static boolean computeHasSupportedPayloads(final PayloadRef[] refs) {
-    for (final PayloadRef ref : refs) {
-      final PayloadRefKind kind = ref.kind();
-      if (kind != PayloadRefKind.VALUE_BLOB && kind != PayloadRefKind.ATTRIBUTE_VECTOR
-          && kind != PayloadRefKind.NAMESPACE_VECTOR) {
-        return false;
-      }
-    }
-    return true;
-  }
-
-  public static NodeKindLayout unsupported(final NodeKind nodeKind) {
-    final int[] unsupportedOffsets = new int[FIELD_COUNT];
-    Arrays.fill(unsupportedOffsets, UNSUPPORTED_FIELD_OFFSET);
-    return new NodeKindLayout(nodeKind, 0, false, unsupportedOffsets, new PayloadRef[0]);
-  }
-
-  public static Builder builder(final NodeKind nodeKind) {
-    return new Builder(nodeKind);
-  }
-
-  public NodeKind nodeKind() {
-    return nodeKind;
-  }
-
-  public int fixedSlotSizeInBytes() {
-    return fixedSlotSizeInBytes;
-  }
-
-  public boolean isFixedSlotSupported() {
-    return fixedSlotSupported;
-  }
-
-  public int offsetOfOrMinusOne(final StructuralField field) {
-    return offsets[Objects.requireNonNull(field, "field must not be null").ordinal()];
-  }
-
-  /**
-   * Hot-path variant of {@link #offsetOfOrMinusOne} that skips null checks.
-   * Only use when the field is known to exist in this layout.
-   */
-  public int offsetUnchecked(final StructuralField field) {
-    return offsets[field.ordinal()];
-  }
-
-  public boolean hasField(final StructuralField field) {
-    return offsetOfOrMinusOne(field) != UNSUPPORTED_FIELD_OFFSET;
-  }
-
-  public int payloadRefCount() {
-    return payloadRefs.length;
-  }
-
-  public PayloadRef payloadRef(final int index) {
-    return payloadRefs[index];
-  }
-
-  /**
-   * Pre-computed result of whether all payload refs are supported for inline projection.
-   * Avoids iterating payloadRefs on every moveTo call.
-   */
-  public boolean hasSupportedPayloads() {
-    return hasSupportedPayloads;
-  }
-
-  public static final class Builder {
-    private final NodeKind nodeKind;
-    private final int[] offsets = new int[FIELD_COUNT];
-    private final List payloadRefs = new ArrayList<>();
-    private int cursor;
-
-    private Builder(final NodeKind nodeKind) {
-      this.nodeKind = Objects.requireNonNull(nodeKind);
-      Arrays.fill(offsets, UNSUPPORTED_FIELD_OFFSET);
-    }
-
-    public Builder addField(final StructuralField field) {
-      Objects.requireNonNull(field, "field must not be null");
-      if (offsets[field.ordinal()] != UNSUPPORTED_FIELD_OFFSET) {
-        throw new IllegalArgumentException("Field already registered: " + field);
-      }
-      offsets[field.ordinal()] = cursor;
-      cursor += field.widthInBytes();
-      return this;
-    }
-
-    public Builder addPadding(final int bytes) {
-      if (bytes < 0) {
-        throw new IllegalArgumentException("Padding bytes must be >= 0");
-      }
-      cursor += bytes;
-      return this;
-    }
-
-    public Builder addPayloadRef(final String name, final PayloadRefKind kind) {
-      final int pointerOffset = cursor;
-      final PayloadRef payloadRef =
-          new PayloadRef(name, kind, pointerOffset, pointerOffset + PayloadRef.POINTER_WIDTH_BYTES,
-              pointerOffset + PayloadRef.POINTER_WIDTH_BYTES + PayloadRef.LENGTH_WIDTH_BYTES);
-      payloadRefs.add(payloadRef);
-      cursor += PayloadRef.TOTAL_WIDTH_BYTES;
-      return this;
-    }
-
-    public NodeKindLayout build() {
-      return new NodeKindLayout(nodeKind, cursor, true, offsets, payloadRefs.toArray(PayloadRef[]::new));
-    }
-  }
-}
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/layout/NodeKindLayouts.java b/bundles/sirix-core/src/main/java/io/sirix/node/layout/NodeKindLayouts.java
deleted file mode 100644
index 2d76a55f1..000000000
--- a/bundles/sirix-core/src/main/java/io/sirix/node/layout/NodeKindLayouts.java
+++ /dev/null
@@ -1,268 +0,0 @@
-package io.sirix.node.layout;
-
-import io.sirix.node.NodeKind;
-
-import java.util.Objects;
-
-/**
- * Registry for fixed-slot layout contracts per {@link NodeKind}.
- */
-public final class NodeKindLayouts {
-  private static final NodeKind[] NODE_KINDS = NodeKind.values();
-  private static final NodeKindLayout[] LAYOUTS_BY_ORDINAL = new NodeKindLayout[NODE_KINDS.length];
-
-  static {
-    for (final NodeKind kind : NODE_KINDS) {
-      LAYOUTS_BY_ORDINAL[kind.ordinal()] = NodeKindLayout.unsupported(kind);
-    }
-
-    registerXmlLayouts();
-    registerJsonLayouts();
-  }
-
-  private NodeKindLayouts() {}
-
-  public static NodeKindLayout layoutFor(final NodeKind nodeKind) {
-    return LAYOUTS_BY_ORDINAL[Objects.requireNonNull(nodeKind, "nodeKind must not be null").ordinal()];
-  }
-
-  public static boolean hasFixedSlotLayout(final NodeKind nodeKind) {
-    return layoutFor(nodeKind).isFixedSlotSupported();
-  }
-
-  private static void registerXmlLayouts() {
-    put(NodeKind.XML_DOCUMENT,
-        NodeKindLayout.builder(NodeKind.XML_DOCUMENT)
-                      .addField(StructuralField.FIRST_CHILD_KEY)
-                      .addField(StructuralField.LAST_CHILD_KEY)
-                      .addField(StructuralField.CHILD_COUNT)
-                      .addField(StructuralField.DESCENDANT_COUNT)
-                      .addField(StructuralField.HASH)
-                      .build());
-
-    put(NodeKind.ELEMENT,
-        NodeKindLayout.builder(NodeKind.ELEMENT)
-                      .addField(StructuralField.PARENT_KEY)
-                      .addField(StructuralField.RIGHT_SIBLING_KEY)
-                      .addField(StructuralField.LEFT_SIBLING_KEY)
-                      .addField(StructuralField.FIRST_CHILD_KEY)
-                      .addField(StructuralField.LAST_CHILD_KEY)
-                      .addField(StructuralField.PATH_NODE_KEY)
-                      .addField(StructuralField.PREFIX_KEY)
-                      .addField(StructuralField.LOCAL_NAME_KEY)
-                      .addField(StructuralField.URI_KEY)
-                      .addField(StructuralField.PREVIOUS_REVISION)
-                      .addField(StructuralField.LAST_MODIFIED_REVISION)
-                      .addField(StructuralField.HASH)
-                      .addField(StructuralField.CHILD_COUNT)
-                      .addField(StructuralField.DESCENDANT_COUNT)
-                      .addPayloadRef("attributes", PayloadRefKind.ATTRIBUTE_VECTOR)
-                      .addPayloadRef("namespaces", PayloadRefKind.NAMESPACE_VECTOR)
-                      .build());
-
-    put(NodeKind.ATTRIBUTE,
-        NodeKindLayout.builder(NodeKind.ATTRIBUTE)
-                      .addField(StructuralField.PARENT_KEY)
-                      .addField(StructuralField.PATH_NODE_KEY)
-                      .addField(StructuralField.PREFIX_KEY)
-                      .addField(StructuralField.LOCAL_NAME_KEY)
-                      .addField(StructuralField.URI_KEY)
-                      .addField(StructuralField.PREVIOUS_REVISION)
-                      .addField(StructuralField.LAST_MODIFIED_REVISION)
-                      .addField(StructuralField.HASH)
-                      .addPayloadRef("value", PayloadRefKind.VALUE_BLOB)
-                      .build());
-
-    put(NodeKind.NAMESPACE,
-        NodeKindLayout.builder(NodeKind.NAMESPACE)
-                      .addField(StructuralField.PARENT_KEY)
-                      .addField(StructuralField.PATH_NODE_KEY)
-                      .addField(StructuralField.PREFIX_KEY)
-                      .addField(StructuralField.LOCAL_NAME_KEY)
-                      .addField(StructuralField.URI_KEY)
-                      .addField(StructuralField.PREVIOUS_REVISION)
-                      .addField(StructuralField.LAST_MODIFIED_REVISION)
-                      .addField(StructuralField.HASH)
-                      .build());
-
-    put(NodeKind.TEXT,
-        NodeKindLayout.builder(NodeKind.TEXT)
-                      .addField(StructuralField.PARENT_KEY)
-                      .addField(StructuralField.RIGHT_SIBLING_KEY)
-                      .addField(StructuralField.LEFT_SIBLING_KEY)
-                      .addField(StructuralField.PREVIOUS_REVISION)
-                      .addField(StructuralField.LAST_MODIFIED_REVISION)
-                      .addField(StructuralField.HASH)
-                      .addPayloadRef("value", PayloadRefKind.VALUE_BLOB)
-                      .build());
-
-    put(NodeKind.COMMENT,
-        NodeKindLayout.builder(NodeKind.COMMENT)
-                      .addField(StructuralField.PARENT_KEY)
-                      .addField(StructuralField.RIGHT_SIBLING_KEY)
-                      .addField(StructuralField.LEFT_SIBLING_KEY)
-                      .addField(StructuralField.PREVIOUS_REVISION)
-                      .addField(StructuralField.LAST_MODIFIED_REVISION)
-                      .addField(StructuralField.HASH)
-                      .addPayloadRef("value", PayloadRefKind.VALUE_BLOB)
-                      .build());
-
-    put(NodeKind.PROCESSING_INSTRUCTION,
-        NodeKindLayout.builder(NodeKind.PROCESSING_INSTRUCTION)
-                      .addField(StructuralField.PARENT_KEY)
-                      .addField(StructuralField.RIGHT_SIBLING_KEY)
-                      .addField(StructuralField.LEFT_SIBLING_KEY)
-                      .addField(StructuralField.FIRST_CHILD_KEY)
-                      .addField(StructuralField.LAST_CHILD_KEY)
-                      .addField(StructuralField.PATH_NODE_KEY)
-                      .addField(StructuralField.PREFIX_KEY)
-                      .addField(StructuralField.LOCAL_NAME_KEY)
-                      .addField(StructuralField.URI_KEY)
-                      .addField(StructuralField.PREVIOUS_REVISION)
-                      .addField(StructuralField.LAST_MODIFIED_REVISION)
-                      .addField(StructuralField.HASH)
-                      .addField(StructuralField.CHILD_COUNT)
-                      .addField(StructuralField.DESCENDANT_COUNT)
-                      .addPayloadRef("value", PayloadRefKind.VALUE_BLOB)
-                      .build());
-  }
-
-  private static void registerJsonLayouts() {
-    put(NodeKind.JSON_DOCUMENT,
-        NodeKindLayout.builder(NodeKind.JSON_DOCUMENT)
-                      .addField(StructuralField.FIRST_CHILD_KEY)
-                      .addField(StructuralField.LAST_CHILD_KEY)
-                      .addField(StructuralField.CHILD_COUNT)
-                      .addField(StructuralField.DESCENDANT_COUNT)
-                      .addField(StructuralField.HASH)
-                      .build());
-
-    put(NodeKind.OBJECT,
-        NodeKindLayout.builder(NodeKind.OBJECT)
-                      .addField(StructuralField.PARENT_KEY)
-                      .addField(StructuralField.RIGHT_SIBLING_KEY)
-                      .addField(StructuralField.LEFT_SIBLING_KEY)
-                      .addField(StructuralField.FIRST_CHILD_KEY)
-                      .addField(StructuralField.LAST_CHILD_KEY)
-                      .addField(StructuralField.PREVIOUS_REVISION)
-                      .addField(StructuralField.LAST_MODIFIED_REVISION)
-                      .addField(StructuralField.HASH)
-                      .addField(StructuralField.CHILD_COUNT)
-                      .addField(StructuralField.DESCENDANT_COUNT)
-                      .build());
-
-    put(NodeKind.ARRAY,
-        NodeKindLayout.builder(NodeKind.ARRAY)
-                      .addField(StructuralField.PARENT_KEY)
-                      .addField(StructuralField.RIGHT_SIBLING_KEY)
-                      .addField(StructuralField.LEFT_SIBLING_KEY)
-                      .addField(StructuralField.FIRST_CHILD_KEY)
-                      .addField(StructuralField.LAST_CHILD_KEY)
-                      .addField(StructuralField.PATH_NODE_KEY)
-                      .addField(StructuralField.PREVIOUS_REVISION)
-                      .addField(StructuralField.LAST_MODIFIED_REVISION)
-                      .addField(StructuralField.HASH)
-                      .addField(StructuralField.CHILD_COUNT)
-                      .addField(StructuralField.DESCENDANT_COUNT)
-                      .build());
-
-    put(NodeKind.OBJECT_KEY,
-        NodeKindLayout.builder(NodeKind.OBJECT_KEY)
-                      .addField(StructuralField.PARENT_KEY)
-                      .addField(StructuralField.RIGHT_SIBLING_KEY)
-                      .addField(StructuralField.LEFT_SIBLING_KEY)
-                      .addField(StructuralField.FIRST_CHILD_KEY)
-                      .addField(StructuralField.LAST_CHILD_KEY)
-                      .addField(StructuralField.PATH_NODE_KEY)
-                      .addField(StructuralField.NAME_KEY)
-                      .addField(StructuralField.PREVIOUS_REVISION)
-                      .addField(StructuralField.LAST_MODIFIED_REVISION)
-                      .addField(StructuralField.HASH)
-                      .addField(StructuralField.DESCENDANT_COUNT)
-                      .build());
-
-    put(NodeKind.STRING_VALUE,
-        NodeKindLayout.builder(NodeKind.STRING_VALUE)
-                      .addField(StructuralField.PARENT_KEY)
-                      .addField(StructuralField.RIGHT_SIBLING_KEY)
-                      .addField(StructuralField.LEFT_SIBLING_KEY)
-                      .addField(StructuralField.PREVIOUS_REVISION)
-                      .addField(StructuralField.LAST_MODIFIED_REVISION)
-                      .addField(StructuralField.HASH)
-                      .addPayloadRef("value", PayloadRefKind.VALUE_BLOB)
-                      .build());
-
-    put(NodeKind.NUMBER_VALUE,
-        NodeKindLayout.builder(NodeKind.NUMBER_VALUE)
-                      .addField(StructuralField.PARENT_KEY)
-                      .addField(StructuralField.RIGHT_SIBLING_KEY)
-                      .addField(StructuralField.LEFT_SIBLING_KEY)
-                      .addField(StructuralField.PREVIOUS_REVISION)
-                      .addField(StructuralField.LAST_MODIFIED_REVISION)
-                      .addField(StructuralField.HASH)
-                      .addPayloadRef("number", PayloadRefKind.VALUE_BLOB)
-                      .build());
-
-    put(NodeKind.BOOLEAN_VALUE,
-        NodeKindLayout.builder(NodeKind.BOOLEAN_VALUE)
-                      .addField(StructuralField.PARENT_KEY)
-                      .addField(StructuralField.RIGHT_SIBLING_KEY)
-                      .addField(StructuralField.LEFT_SIBLING_KEY)
-                      .addField(StructuralField.PREVIOUS_REVISION)
-                      .addField(StructuralField.LAST_MODIFIED_REVISION)
-                      .addField(StructuralField.HASH)
-                      .addField(StructuralField.BOOLEAN_VALUE)
-                      .addPadding(7)
-                      .build());
-
-    put(NodeKind.NULL_VALUE,
-        NodeKindLayout.builder(NodeKind.NULL_VALUE)
-                      .addField(StructuralField.PARENT_KEY)
-                      .addField(StructuralField.RIGHT_SIBLING_KEY)
-                      .addField(StructuralField.LEFT_SIBLING_KEY)
-                      .addField(StructuralField.PREVIOUS_REVISION)
-                      .addField(StructuralField.LAST_MODIFIED_REVISION)
-                      .addField(StructuralField.HASH)
-                      .build());
-
-    put(NodeKind.OBJECT_STRING_VALUE,
-        NodeKindLayout.builder(NodeKind.OBJECT_STRING_VALUE)
-                      .addField(StructuralField.PARENT_KEY)
-                      .addField(StructuralField.PREVIOUS_REVISION)
-                      .addField(StructuralField.LAST_MODIFIED_REVISION)
-                      .addField(StructuralField.HASH)
-                      .addPayloadRef("value", PayloadRefKind.VALUE_BLOB)
-                      .build());
-
-    put(NodeKind.OBJECT_NUMBER_VALUE,
-        NodeKindLayout.builder(NodeKind.OBJECT_NUMBER_VALUE)
-                      .addField(StructuralField.PARENT_KEY)
-                      .addField(StructuralField.PREVIOUS_REVISION)
-                      .addField(StructuralField.LAST_MODIFIED_REVISION)
-                      .addField(StructuralField.HASH)
-                      .addPayloadRef("number", PayloadRefKind.VALUE_BLOB)
-                      .build());
-
-    put(NodeKind.OBJECT_BOOLEAN_VALUE,
-        NodeKindLayout.builder(NodeKind.OBJECT_BOOLEAN_VALUE)
-                      .addField(StructuralField.PARENT_KEY)
-                      .addField(StructuralField.PREVIOUS_REVISION)
-                      .addField(StructuralField.LAST_MODIFIED_REVISION)
-                      .addField(StructuralField.HASH)
-                      .addField(StructuralField.BOOLEAN_VALUE)
-                      .addPadding(7)
-                      .build());
-
-    put(NodeKind.OBJECT_NULL_VALUE,
-        NodeKindLayout.builder(NodeKind.OBJECT_NULL_VALUE)
-                      .addField(StructuralField.PARENT_KEY)
-                      .addField(StructuralField.PREVIOUS_REVISION)
-                      .addField(StructuralField.LAST_MODIFIED_REVISION)
-                      .addField(StructuralField.HASH)
-                      .build());
-  }
-
-  private static void put(final NodeKind kind, final NodeKindLayout layout) {
-    LAYOUTS_BY_ORDINAL[kind.ordinal()] = layout;
-  }
-}
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/layout/PayloadRef.java b/bundles/sirix-core/src/main/java/io/sirix/node/layout/PayloadRef.java
deleted file mode 100644
index df7bb6a3e..000000000
--- a/bundles/sirix-core/src/main/java/io/sirix/node/layout/PayloadRef.java
+++ /dev/null
@@ -1,28 +0,0 @@
-package io.sirix.node.layout;
-
-import java.util.Objects;
-
-/**
- * Pointer metadata embedded in a fixed slot for out-of-line payload blocks.
- */
-public record PayloadRef(String name, PayloadRefKind kind, int pointerOffset, int lengthOffset, int flagsOffset) {
-
-  public static final int POINTER_WIDTH_BYTES = Long.BYTES;
-  public static final int LENGTH_WIDTH_BYTES = Integer.BYTES;
-  public static final int FLAGS_WIDTH_BYTES = Integer.BYTES;
-  public static final int TOTAL_WIDTH_BYTES = POINTER_WIDTH_BYTES + LENGTH_WIDTH_BYTES + FLAGS_WIDTH_BYTES;
-
-  public PayloadRef {
-    Objects.requireNonNull(name, "name must not be null");
-    Objects.requireNonNull(kind, "kind must not be null");
-    if (pointerOffset < 0) {
-      throw new IllegalArgumentException("pointerOffset must be >= 0");
-    }
-    if (lengthOffset != pointerOffset + POINTER_WIDTH_BYTES) {
-      throw new IllegalArgumentException("lengthOffset must directly follow pointerOffset");
-    }
-    if (flagsOffset != lengthOffset + LENGTH_WIDTH_BYTES) {
-      throw new IllegalArgumentException("flagsOffset must directly follow lengthOffset");
-    }
-  }
-}
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/layout/PayloadRefKind.java b/bundles/sirix-core/src/main/java/io/sirix/node/layout/PayloadRefKind.java
deleted file mode 100644
index 497fdb8db..000000000
--- a/bundles/sirix-core/src/main/java/io/sirix/node/layout/PayloadRefKind.java
+++ /dev/null
@@ -1,8 +0,0 @@
-package io.sirix.node.layout;
-
-/**
- * Classification of out-of-line payload blocks referenced by a fixed slot.
- */
-public enum PayloadRefKind {
-  VALUE_BLOB, ATTRIBUTE_VECTOR, NAMESPACE_VECTOR
-}
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/layout/SlotLayoutAccessors.java b/bundles/sirix-core/src/main/java/io/sirix/node/layout/SlotLayoutAccessors.java
deleted file mode 100644
index 51ece60a7..000000000
--- a/bundles/sirix-core/src/main/java/io/sirix/node/layout/SlotLayoutAccessors.java
+++ /dev/null
@@ -1,205 +0,0 @@
-package io.sirix.node.layout;
-
-import java.lang.foreign.MemorySegment;
-import java.lang.foreign.ValueLayout;
-import java.util.Objects;
-
-/**
- * Primitive-only accessors for fixed-size slot layouts backed by {@link MemorySegment}.
- *
- * 

- * This utility is designed for hot paths: no boxing, no temporary object allocation.
- *
- * 

- * Each accessor has two overloads:
- * 
    
- * 
  • Without {@code baseOffset} — reads/writes relative to the start of the segment (legacy
- * slice-based API).
    • 
- * 
  • With {@code long baseOffset} — reads/writes at {@code baseOffset + fieldOffset}, allowing
- * callers to pass the full {@code slotMemory} plus an offset instead of allocating an
- * {@code asSlice()} per call.
    • 
- * 

- */
-public final class SlotLayoutAccessors {
-  private static final ValueLayout.OfLong LONG_LAYOUT = ValueLayout.JAVA_LONG_UNALIGNED;
-  private static final ValueLayout.OfInt INT_LAYOUT = ValueLayout.JAVA_INT_UNALIGNED;
-  private static final ValueLayout.OfByte BYTE_LAYOUT = ValueLayout.JAVA_BYTE;
-
-  private SlotLayoutAccessors() {}
-
-  // ── readLongField ──────────────────────────────────────────────────
-
-  public static long readLongField(final MemorySegment slot, final long baseOffset, final NodeKindLayout layout,
-      final StructuralField field) {
-    final int offset = requiredOffset(layout, field);
-    return slot.get(LONG_LAYOUT, baseOffset + offset);
-  }
-
-  public static long readLongField(final MemorySegment slot, final NodeKindLayout layout, final StructuralField field) {
-    return readLongField(slot, 0L, layout, field);
-  }
-
-  // ── writeLongField ─────────────────────────────────────────────────
-
-  public static void writeLongField(final MemorySegment slot, final long baseOffset, final NodeKindLayout layout,
-      final StructuralField field, final long value) {
-    final int offset = requiredOffset(layout, field);
-    slot.set(LONG_LAYOUT, baseOffset + offset, value);
-  }
-
-  public static void writeLongField(final MemorySegment slot, final NodeKindLayout layout, final StructuralField field,
-      final long value) {
-    writeLongField(slot, 0L, layout, field, value);
-  }
-
-  // ── readIntField ───────────────────────────────────────────────────
-
-  public static int readIntField(final MemorySegment slot, final long baseOffset, final NodeKindLayout layout,
-      final StructuralField field) {
-    final int offset = requiredOffset(layout, field);
-    return slot.get(INT_LAYOUT, baseOffset + offset);
-  }
-
-  public static int readIntField(final MemorySegment slot, final NodeKindLayout layout, final StructuralField field) {
-    return readIntField(slot, 0L, layout, field);
-  }
-
-  // ── writeIntField ──────────────────────────────────────────────────
-
-  public static void writeIntField(final MemorySegment slot, final long baseOffset, final NodeKindLayout layout,
-      final StructuralField field, final int value) {
-    final int offset = requiredOffset(layout, field);
-    slot.set(INT_LAYOUT, baseOffset + offset, value);
-  }
-
-  public static void writeIntField(final MemorySegment slot, final NodeKindLayout layout, final StructuralField field,
-      final int value) {
-    writeIntField(slot, 0L, layout, field, value);
-  }
-
-  // ── readBooleanField ───────────────────────────────────────────────
-
-  public static boolean readBooleanField(final MemorySegment slot, final long baseOffset, final NodeKindLayout layout,
-      final StructuralField field) {
-    final int offset = requiredOffset(layout, field);
-    return slot.get(BYTE_LAYOUT, baseOffset + offset) != 0;
-  }
-
-  public static boolean readBooleanField(final MemorySegment slot, final NodeKindLayout layout,
-      final StructuralField field) {
-    return readBooleanField(slot, 0L, layout, field);
-  }
-
-  // ── writeBooleanField ──────────────────────────────────────────────
-
-  public static void writeBooleanField(final MemorySegment slot, final long baseOffset, final NodeKindLayout layout,
-      final StructuralField field, final boolean value) {
-    final int offset = requiredOffset(layout, field);
-    slot.set(BYTE_LAYOUT, baseOffset + offset, value
-        ? (byte) 1
-        : (byte) 0);
-  }
-
-  public static void writeBooleanField(final MemorySegment slot, final NodeKindLayout layout,
-      final StructuralField field, final boolean value) {
-    writeBooleanField(slot, 0L, layout, field, value);
-  }
-
-  // ── readPayloadPointer ─────────────────────────────────────────────
-
-  public static long readPayloadPointer(final MemorySegment slot, final long baseOffset, final NodeKindLayout layout,
-      final int payloadRefIndex) {
-    final PayloadRef payloadRef = payloadRef(layout, payloadRefIndex);
-    return slot.get(LONG_LAYOUT, baseOffset + payloadRef.pointerOffset());
-  }
-
-  public static long readPayloadPointer(final MemorySegment slot, final NodeKindLayout layout,
-      final int payloadRefIndex) {
-    return readPayloadPointer(slot, 0L, layout, payloadRefIndex);
-  }
-
-  // ── readPayloadLength ──────────────────────────────────────────────
-
-  public static int readPayloadLength(final MemorySegment slot, final long baseOffset, final NodeKindLayout layout,
-      final int payloadRefIndex) {
-    final PayloadRef payloadRef = payloadRef(layout, payloadRefIndex);
-    return slot.get(INT_LAYOUT, baseOffset + payloadRef.lengthOffset());
-  }
-
-  public static int readPayloadLength(final MemorySegment slot, final NodeKindLayout layout,
-      final int payloadRefIndex) {
-    return readPayloadLength(slot, 0L, layout, payloadRefIndex);
-  }
-
-  // ── readPayloadFlags ───────────────────────────────────────────────
-
-  public static int readPayloadFlags(final MemorySegment slot, final long baseOffset, final NodeKindLayout layout,
-      final int payloadRefIndex) {
-    final PayloadRef payloadRef = payloadRef(layout, payloadRefIndex);
-    return slot.get(INT_LAYOUT, baseOffset + payloadRef.flagsOffset());
-  }
-
-  public static int readPayloadFlags(final MemorySegment slot, final NodeKindLayout layout, final int payloadRefIndex) {
-    return readPayloadFlags(slot, 0L, layout, payloadRefIndex);
-  }
-
-  // ── writePayloadRef ────────────────────────────────────────────────
-
-  public static void writePayloadRef(final MemorySegment slot, final long baseOffset, final NodeKindLayout layout,
-      final int payloadRefIndex, final long pointer, final int length, final int flags) {
-    if (length < 0) {
-      throw new IllegalArgumentException("length must be >= 0");
-    }
-    if (flags < 0) {
-      throw new IllegalArgumentException("flags must be >= 0");
-    }
-    final PayloadRef payloadRef = payloadRef(layout, payloadRefIndex);
-    slot.set(LONG_LAYOUT, baseOffset + payloadRef.pointerOffset(), pointer);
-    slot.set(INT_LAYOUT, baseOffset + payloadRef.lengthOffset(), length);
-    slot.set(INT_LAYOUT, baseOffset + payloadRef.flagsOffset(), flags);
-  }
-
-  public static void writePayloadRef(final MemorySegment slot, final NodeKindLayout layout, final int payloadRefIndex,
-      final long pointer, final int length, final int flags) {
-    writePayloadRef(slot, 0L, layout, payloadRefIndex, pointer, length, flags);
-  }
-
-  // ── unchecked hot-path variants ─────────────────────────────────────
-  // These skip null checks and bounds validation for maximum performance.
-  // Only use when layout and field are known to be valid (e.g., from pre-computed static finals).
-
-  public static long readLongFieldUnchecked(final MemorySegment slot, final long baseOffset,
-      final NodeKindLayout layout, final StructuralField field) {
-    return slot.get(LONG_LAYOUT, baseOffset + layout.offsetUnchecked(field));
-  }
-
-  public static int readIntFieldUnchecked(final MemorySegment slot, final long baseOffset,
-      final NodeKindLayout layout, final StructuralField field) {
-    return slot.get(INT_LAYOUT, baseOffset + layout.offsetUnchecked(field));
-  }
-
-  public static boolean readBooleanFieldUnchecked(final MemorySegment slot, final long baseOffset,
-      final NodeKindLayout layout, final StructuralField field) {
-    return slot.get(BYTE_LAYOUT, baseOffset + layout.offsetUnchecked(field)) != 0;
-  }
-
-  // ── helpers ────────────────────────────────────────────────────────
-
-  private static int requiredOffset(final NodeKindLayout layout, final StructuralField field) {
-    final int offset = Objects.requireNonNull(layout, "layout must not be null")
-                              .offsetOfOrMinusOne(Objects.requireNonNull(field, "field must not be null"));
-    if (offset < 0) {
-      throw new IllegalArgumentException("Field " + field + " is not part of layout for " + layout.nodeKind());
-    }
-    return offset;
-  }
-
-  private static PayloadRef payloadRef(final NodeKindLayout layout, final int payloadRefIndex) {
-    Objects.requireNonNull(layout, "layout must not be null");
-    if (payloadRefIndex < 0 || payloadRefIndex >= layout.payloadRefCount()) {
-      throw new IllegalArgumentException("Invalid payloadRefIndex " + payloadRefIndex + " for " + layout.nodeKind()
-          + ", count=" + layout.payloadRefCount());
-    }
-    return layout.payloadRef(payloadRefIndex);
-  }
-}
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/layout/StructuralField.java b/bundles/sirix-core/src/main/java/io/sirix/node/layout/StructuralField.java
deleted file mode 100644
index ea5c418ed..000000000
--- a/bundles/sirix-core/src/main/java/io/sirix/node/layout/StructuralField.java
+++ /dev/null
@@ -1,22 +0,0 @@
-package io.sirix.node.layout;
-
-/**
- * Structural fields that are modeled as fixed-width columns in the in-memory slot layout.
- */
-public enum StructuralField {
-  PARENT_KEY(Long.BYTES), RIGHT_SIBLING_KEY(Long.BYTES), LEFT_SIBLING_KEY(Long.BYTES), FIRST_CHILD_KEY(
-      Long.BYTES), LAST_CHILD_KEY(Long.BYTES), PATH_NODE_KEY(Long.BYTES), PREVIOUS_REVISION(
-          Integer.BYTES), LAST_MODIFIED_REVISION(Integer.BYTES), PREFIX_KEY(Integer.BYTES), LOCAL_NAME_KEY(
-              Integer.BYTES), URI_KEY(Integer.BYTES), NAME_KEY(Integer.BYTES), HASH(
-                  Long.BYTES), CHILD_COUNT(Long.BYTES), DESCENDANT_COUNT(Long.BYTES), BOOLEAN_VALUE(Byte.BYTES);
-
-  private final int widthInBytes;
-
-  StructuralField(final int widthInBytes) {
-    this.widthInBytes = widthInBytes;
-  }
-
-  public int widthInBytes() {
-    return widthInBytes;
-  }
-}
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/xml/AttributeNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/xml/AttributeNode.java
index 039ec08ac..effecad65 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/xml/AttributeNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/xml/AttributeNode.java
@@ -43,30 +43,29 @@
 import io.sirix.node.NodeKind;
 import io.sirix.node.SirixDeweyID;
 import io.sirix.node.immutable.xml.ImmutableAttributeNode;
+import io.sirix.node.interfaces.FlyweightNode;
 import io.sirix.node.interfaces.NameNode;
 import io.sirix.node.interfaces.Node;
-import io.sirix.node.interfaces.ReusableNodeProxy;
 import io.sirix.node.interfaces.ValueNode;
 import io.sirix.node.interfaces.immutable.ImmutableXmlNode;
-import io.sirix.node.layout.NodeKindLayout;
-import io.sirix.node.layout.SlotLayoutAccessors;
-import io.sirix.node.layout.StructuralField;
+import io.sirix.page.KeyValueLeafPage;
+import io.sirix.page.NodeFieldLayout;
 import io.sirix.settings.Constants;
 import io.sirix.settings.Fixed;
 import io.sirix.utils.NamePageHash;
+import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
 import net.openhft.hashing.LongHashFunction;
 import org.checkerframework.checker.index.qual.NonNegative;
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
-import java.lang.foreign.MemorySegment;
-
 /**
  * Node representing an attribute, using primitive fields.
  *
  * @author Johannes Lichtenberger
  */
-public final class AttributeNode implements ValueNode, NameNode, ImmutableXmlNode, ReusableNodeProxy {
+public final class AttributeNode implements ValueNode, NameNode, ImmutableXmlNode, FlyweightNode {
 
   // === PRIMITIVE FIELDS ===
   private long nodeKey;
@@ -86,17 +85,35 @@ public final class AttributeNode implements ValueNode, NameNode, ImmutableXmlNod
   private int lazyValueLength;
   private boolean valueParsed = true;
 
-  // === METADATA LAZY SUPPORT ===
-  private long lazyBaseOffset;
-  private NodeKindLayout fixedSlotLayout;
-  private boolean metadataParsed = true;
-
   // === NON-SERIALIZED FIELDS ===
   private LongHashFunction hashFunction;
   private SirixDeweyID sirixDeweyID;
   private byte[] deweyIDBytes;
   private QNm qNm;
 
+  // ==================== FLYWEIGHT BINDING (LeanStore page-direct access) ====================
+  private MemorySegment page;
+  private long recordBase;
+  private long dataRegionStart;
+  private int slotIndex;
+  private boolean writeSingleton;
+  private KeyValueLeafPage ownerPage;
+  private final int[] heapOffsets;
+  private static final int FIELD_COUNT = NodeFieldLayout.ATTRIBUTE_FIELD_COUNT;
+
+  /**
+   * Constructor for flyweight binding.
+   * All fields except nodeKey and hashFunction will be read from page memory after bind().
+   *
+   * @param nodeKey the node key
+   * @param hashFunction the hash function from resource config
+   */
+  public AttributeNode(long nodeKey, LongHashFunction hashFunction) {
+    this.nodeKey = nodeKey;
+    this.hashFunction = hashFunction;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
+
   /**
    * Primary constructor with all primitive fields.
    */
@@ -116,6 +133,7 @@ public AttributeNode(long nodeKey, long parentKey, int previousRevision, int las
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyID;
     this.qNm = qNm;
+    this.heapOffsets = new int[FIELD_COUNT];
   }
 
   /**
@@ -137,6 +155,7 @@ public AttributeNode(long nodeKey, long parentKey, int previousRevision, int las
     this.hashFunction = hashFunction;
     this.sirixDeweyID = deweyID;
     this.qNm = qNm;
+    this.heapOffsets = new int[FIELD_COUNT];
   }
 
   @Override
@@ -156,109 +175,269 @@ public void setNodeKey(long nodeKey) {
 
   @Override
   public long getParentKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.ATTR_PARENT_KEY, nodeKey);
+    }
     return parentKey;
   }
 
-  public void setParentKey(long parentKey) {
+  public void setParentKey(final long parentKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.ATTR_PARENT_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(parentKey, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, parentKey, nodeKey);
+        return;
+      }
+      resizeParentKey(parentKey);
+      return;
+    }
     this.parentKey = parentKey;
   }
 
+  private void resizeParentKey(final long parentKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ATTR_PARENT_KEY, NodeFieldLayout.ATTRIBUTE_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, parentKey, nodeKey));
+  }
+
   @Override
   public boolean hasParent() {
-    return parentKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getParentKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public long getPathNodeKey() {
-    if (!metadataParsed)
-      parseMetadataFields();
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.ATTR_PATH_NODE_KEY, nodeKey);
+    }
     return pathNodeKey;
   }
 
   @Override
-  public void setPathNodeKey(@NonNegative long pathNodeKey) {
+  public void setPathNodeKey(@NonNegative final long pathNodeKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.ATTR_PATH_NODE_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(pathNodeKey, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, pathNodeKey, nodeKey);
+        return;
+      }
+      resizePathNodeKey(pathNodeKey);
+      return;
+    }
     this.pathNodeKey = pathNodeKey;
   }
 
+  private void resizePathNodeKey(final long pathNodeKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ATTR_PATH_NODE_KEY, NodeFieldLayout.ATTRIBUTE_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, pathNodeKey, nodeKey));
+  }
+
   @Override
   public int getPrefixKey() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.ATTR_PREFIX_KEY);
+    }
     return prefixKey;
   }
 
   @Override
-  public void setPrefixKey(int prefixKey) {
+  public void setPrefixKey(final int prefixKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.ATTR_PREFIX_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(prefixKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, prefixKey);
+        return;
+      }
+      resizePrefixKey(prefixKey);
+      return;
+    }
     this.prefixKey = prefixKey;
   }
 
+  private void resizePrefixKey(final int prefixKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ATTR_PREFIX_KEY, NodeFieldLayout.ATTRIBUTE_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, prefixKey));
+  }
+
   @Override
   public int getLocalNameKey() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.ATTR_LOCAL_NAME_KEY);
+    }
     return localNameKey;
   }
 
   @Override
-  public void setLocalNameKey(int localNameKey) {
+  public void setLocalNameKey(final int localNameKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.ATTR_LOCAL_NAME_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(localNameKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, localNameKey);
+        return;
+      }
+      resizeLocalNameKey(localNameKey);
+      return;
+    }
     this.localNameKey = localNameKey;
   }
 
+  private void resizeLocalNameKey(final int localNameKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ATTR_LOCAL_NAME_KEY, NodeFieldLayout.ATTRIBUTE_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, localNameKey));
+  }
+
   @Override
   public int getURIKey() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.ATTR_URI_KEY);
+    }
     return uriKey;
   }
 
   @Override
-  public void setURIKey(int uriKey) {
+  public void setURIKey(final int uriKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.ATTR_URI_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(uriKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, uriKey);
+        return;
+      }
+      resizeURIKey(uriKey);
+      return;
+    }
     this.uriKey = uriKey;
   }
 
+  private void resizeURIKey(final int uriKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ATTR_URI_KEY, NodeFieldLayout.ATTRIBUTE_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, uriKey));
+  }
+
   @Override
   public int getPreviousRevisionNumber() {
-    if (!metadataParsed)
-      parseMetadataFields();
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.ATTR_PREV_REVISION);
+    }
     return previousRevision;
   }
 
   @Override
-  public void setPreviousRevision(int revision) {
+  public void setPreviousRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.ATTR_PREV_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizePreviousRevision(revision);
+      return;
+    }
     this.previousRevision = revision;
   }
 
+  private void resizePreviousRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ATTR_PREV_REVISION, NodeFieldLayout.ATTRIBUTE_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+  }
+
   @Override
   public int getLastModifiedRevisionNumber() {
-    if (!metadataParsed)
-      parseMetadataFields();
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.ATTR_LAST_MOD_REVISION);
+    }
     return lastModifiedRevision;
   }
 
   @Override
-  public void setLastModifiedRevision(int revision) {
+  public void setLastModifiedRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.ATTR_LAST_MOD_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizeLastModifiedRevision(revision);
+      return;
+    }
     this.lastModifiedRevision = revision;
   }
 
+  private void resizeLastModifiedRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ATTR_LAST_MOD_REVISION, NodeFieldLayout.ATTRIBUTE_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+  }
+
   @Override
   public long getHash() {
-    if (!metadataParsed)
-      parseMetadataFields();
-    if (hash == 0L && hashFunction != null) {
+    // Return stored hash if set by rollingAdd/rollingUpdate, else compute on demand
+    if (hash != 0L) {
+      return hash;
+    }
+    if (hashFunction != null) {
       hash = computeHash(Bytes.threadLocalHashBuffer());
     }
     return hash;
   }
 
   @Override
-  public void setHash(long hash) {
+  public void setHash(final long hash) {
     this.hash = hash;
   }
 
   @Override
   public byte[] getRawValue() {
-    if (!valueParsed) {
+    if (page != null && !valueParsed) {
+      readPayloadFromPage();
+    } else if (!valueParsed) {
       parseLazyValue();
     }
     return value;
   }
 
   @Override
-  public void setRawValue(byte[] value) {
+  public void setRawValue(final byte[] value) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.value = value;
+      this.valueParsed = true;
+      this.lazyValueSource = null;
+      this.lazyValueOffset = 0L;
+      this.lazyValueLength = 0;
+      this.hash = 0L;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
+    if (page != null) unbind();
     this.value = value;
     this.valueParsed = true;
     this.lazyValueSource = null;
@@ -278,8 +457,9 @@ public void setLazyRawValue(Object source, long valueOffset, int valueLength) {
 
   @Override
   public String getValue() {
-    return value != null
-        ? new String(value, Constants.DEFAULT_ENCODING)
+    final byte[] rawValue = getRawValue();
+    return rawValue != null
+        ? new String(rawValue, Constants.DEFAULT_ENCODING)
         : "";
   }
 
@@ -298,7 +478,9 @@ public void setName(QNm name) {
    * interface.
    */
   public byte[] getRawValueWithoutDecompression() {
-    if (!valueParsed) {
+    if (page != null && !valueParsed) {
+      readPayloadFromPage();
+    } else if (!valueParsed) {
       parseLazyValue();
     }
     return value;
@@ -319,6 +501,16 @@ public void setTypeKey(int typeKey) {}
 
   @Override
   public void setDeweyID(SirixDeweyID id) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.sirixDeweyID = id;
+      this.deweyIDBytes = null;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
     this.sirixDeweyID = id;
     this.deweyIDBytes = null;
   }
@@ -348,11 +540,272 @@ public LongHashFunction getHashFunction() {
     return hashFunction;
   }
 
+  // ==================== FLYWEIGHT BIND/UNBIND ====================
+
+  @Override
+  public void bind(final MemorySegment page, final long recordBase, final long nodeKey,
+      final int slotIndex) {
+    this.page = page;
+    this.recordBase = recordBase;
+    this.nodeKey = nodeKey;
+    this.slotIndex = slotIndex;
+    this.dataRegionStart = recordBase + 1 + FIELD_COUNT;
+    this.valueParsed = false;
+    this.lazyValueSource = null;
+    this.hash = 0;
+  }
+
+  @Override
+  public void unbind() {
+    if (page == null) return;
+    final long nk = this.nodeKey;
+    this.parentKey = readDeltaField(NodeFieldLayout.ATTR_PARENT_KEY, nk);
+    this.pathNodeKey = readDeltaField(NodeFieldLayout.ATTR_PATH_NODE_KEY, nk);
+    this.prefixKey = readSignedField(NodeFieldLayout.ATTR_PREFIX_KEY);
+    this.localNameKey = readSignedField(NodeFieldLayout.ATTR_LOCAL_NAME_KEY);
+    this.uriKey = readSignedField(NodeFieldLayout.ATTR_URI_KEY);
+    this.previousRevision = readSignedField(NodeFieldLayout.ATTR_PREV_REVISION);
+    this.lastModifiedRevision = readSignedField(NodeFieldLayout.ATTR_LAST_MOD_REVISION);
+    if (!valueParsed) {
+      readPayloadFromPage();
+    }
+    this.ownerPage = null;
+    this.page = null;
+  }
+
+  @Override
+  public void clearBinding() {
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  @Override
+  public boolean isBound() { return page != null; }
+
+  @Override
+  public boolean isBoundTo(final MemorySegment page) {
+    return this.page == page;
+  }
+
+  @Override
+  public int getSlotIndex() {
+    return slotIndex;
+  }
+
+  @Override public boolean isWriteSingleton() { return writeSingleton; }
+  @Override public void setWriteSingleton(final boolean ws) { this.writeSingleton = ws; }
+  @Override public KeyValueLeafPage getOwnerPage() { return ownerPage; }
+  @Override public void setOwnerPage(final KeyValueLeafPage p) { this.ownerPage = p; }
+
+  @Override
+  public int estimateSerializedSize() {
+    final int payloadLen = value != null ? value.length : 0;
+    return 55 + payloadLen;
+  }
+
+  // ==================== FLYWEIGHT FIELD READ HELPERS ====================
+
+  private long readDeltaField(final int fieldIndex, final long baseKey) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeDeltaFromSegment(page, dataRegionStart + fieldOff, baseKey);
+  }
+
+  private int readSignedField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeSignedFromSegment(page, dataRegionStart + fieldOff);
+  }
+
+  /**
+   * Read the payload (value bytes) directly from page memory when bound.
+   */
+  private void readPayloadFromPage() {
+    final int payloadFieldOff = page.get(ValueLayout.JAVA_BYTE,
+        recordBase + 1 + NodeFieldLayout.ATTR_PAYLOAD) & 0xFF;
+    final long payloadStart = dataRegionStart + payloadFieldOff;
+
+    // Read isCompressed flag (1 byte) - always 0 for attributes, but read for format consistency
+    // skip: payloadStart + 0
+    final long lenOffset = payloadStart + 1;
+
+    // Read value length (varint)
+    final int length = DeltaVarIntCodec.decodeSignedFromSegment(page, lenOffset);
+    final int lenBytes = DeltaVarIntCodec.readSignedVarintWidth(page, lenOffset);
+
+    // Read value bytes
+    final long dataOffset = lenOffset + lenBytes;
+    this.value = new byte[length];
+    if (length > 0) {
+      MemorySegment.copy(page, ValueLayout.JAVA_BYTE, dataOffset, this.value, 0, length);
+    }
+    this.valueParsed = true;
+  }
+
+  // ==================== DIRECT WRITE ====================
+
+  /**
+   * Encode an AttributeNode record directly to a MemorySegment from parameter values.
+   * Static -- reads nothing from any instance. Zero field intermediation.
+   *
+   * @param target       the target MemorySegment (reinterpreted slotted page)
+   * @param offset       absolute byte offset to write at
+   * @param heapOffsets  pre-allocated offset array (reused, FIELD_COUNT elements)
+   * @param nodeKey      the node key (delta base for structural keys)
+   * @param parentKey    the parent node key
+   * @param pathNodeKey  the path node key
+   * @param prefixKey    the prefix key
+   * @param localNameKey the local name key
+   * @param uriKey       the URI key
+   * @param prevRev      the previous revision number
+   * @param lastModRev   the last modified revision number
+   * @param rawValue     the raw value bytes
+   * @return the total number of bytes written
+   */
+  public static int writeNewRecord(final MemorySegment target, final long offset,
+      final int[] heapOffsets, final long nodeKey,
+      final long parentKey, final long pathNodeKey,
+      final int prefixKey, final int localNameKey, final int uriKey,
+      final int prevRev, final int lastModRev,
+      final byte[] rawValue) {
+    long pos = offset;
+
+    // Write nodeKind byte
+    target.set(ValueLayout.JAVA_BYTE, pos, NodeKind.ATTRIBUTE.getId());
+    pos++;
+
+    // Reserve space for offset table
+    final long offsetTableStart = pos;
+    pos += FIELD_COUNT;
+
+    // Data region start
+    final long dataStart = pos;
+
+    // Field 0: parentKey (delta-varint)
+    heapOffsets[NodeFieldLayout.ATTR_PARENT_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, parentKey, nodeKey);
+
+    // Field 1: pathNodeKey (delta-varint)
+    heapOffsets[NodeFieldLayout.ATTR_PATH_NODE_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, pathNodeKey, nodeKey);
+
+    // Field 2: prefixKey (signed varint)
+    heapOffsets[NodeFieldLayout.ATTR_PREFIX_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, prefixKey);
+
+    // Field 3: localNameKey (signed varint)
+    heapOffsets[NodeFieldLayout.ATTR_LOCAL_NAME_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, localNameKey);
+
+    // Field 4: uriKey (signed varint)
+    heapOffsets[NodeFieldLayout.ATTR_URI_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, uriKey);
+
+    // Field 5: prevRevision (signed varint)
+    heapOffsets[NodeFieldLayout.ATTR_PREV_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, prevRev);
+
+    // Field 6: lastModRevision (signed varint)
+    heapOffsets[NodeFieldLayout.ATTR_LAST_MOD_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, lastModRev);
+
+    // Field 7: payload [isCompressed=0:1][valueLength:varint][value:bytes]
+    heapOffsets[NodeFieldLayout.ATTR_PAYLOAD] = (int) (pos - dataStart);
+    target.set(ValueLayout.JAVA_BYTE, pos, (byte) 0); // attributes are never compressed
+    pos++;
+    final byte[] val = rawValue != null ? rawValue : new byte[0];
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, val.length);
+    if (val.length > 0) {
+      MemorySegment.copy(val, 0, target, ValueLayout.JAVA_BYTE, pos, val.length);
+      pos += val.length;
+    }
+
+    // Write offset table
+    for (int i = 0; i < FIELD_COUNT; i++) {
+      target.set(ValueLayout.JAVA_BYTE, offsetTableStart + i, (byte) heapOffsets[i]);
+    }
+
+    return (int) (pos - offset);
+  }
+
+  /**
+   * Serialize this node from Java fields. Delegates to static writeNewRecord.
+   */
+  @Override
+  public int serializeToHeap(final MemorySegment target, final long offset) {
+    if (!valueParsed) {
+      if (page != null) {
+        readPayloadFromPage();
+      } else {
+        parseLazyValue();
+      }
+    }
+    return writeNewRecord(target, offset, heapOffsets, nodeKey,
+        parentKey, pathNodeKey, prefixKey, localNameKey, uriKey,
+        previousRevision, lastModifiedRevision, value);
+  }
+
+  /**
+   * Get the pre-allocated heap offsets array for use with static writeNewRecord.
+   */
+  public int[] getHeapOffsets() {
+    return heapOffsets;
+  }
+
+  /**
+   * Set DeweyID fields directly after creation, bypassing write-through.
+   * The DeweyID is already in the page trailer -- this just sets the Java cache fields.
+   */
+  public void setDeweyIDAfterCreation(final SirixDeweyID id, final byte[] bytes) {
+    this.sirixDeweyID = id;
+    this.deweyIDBytes = bytes;
+  }
+
+  // ==================== SNAPSHOT ====================
+
+  /**
+   * Create a deep copy snapshot of this node.
+   * Forces parsing of all lazy fields since snapshot must be independent.
+   */
+  public AttributeNode toSnapshot() {
+    if (page != null) {
+      // Bound mode: read all fields from page
+      if (!valueParsed) {
+        readPayloadFromPage();
+      }
+      return new AttributeNode(nodeKey,
+          readDeltaField(NodeFieldLayout.ATTR_PARENT_KEY, nodeKey),
+          readSignedField(NodeFieldLayout.ATTR_PREV_REVISION),
+          readSignedField(NodeFieldLayout.ATTR_LAST_MOD_REVISION),
+          readDeltaField(NodeFieldLayout.ATTR_PATH_NODE_KEY, nodeKey),
+          readSignedField(NodeFieldLayout.ATTR_PREFIX_KEY),
+          readSignedField(NodeFieldLayout.ATTR_LOCAL_NAME_KEY),
+          readSignedField(NodeFieldLayout.ATTR_URI_KEY),
+          hash,
+          value != null ? value.clone() : null,
+          hashFunction,
+          getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null,
+          qNm);
+    }
+    // Unbound mode: force parse all lazy fields for snapshot (must be complete and independent)
+    if (!valueParsed) {
+      parseLazyValue();
+    }
+    return new AttributeNode(nodeKey, parentKey, previousRevision, lastModifiedRevision,
+        pathNodeKey, prefixKey, localNameKey, uriKey, hash,
+        value != null ? value.clone() : null,
+        hashFunction,
+        getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null,
+        qNm);
+  }
+
+  // ==================== DESERIALIZATION ====================
+
   /**
    * Populate this node from a BytesIn source for singleton reuse.
    */
   public void readFrom(BytesIn source, long nodeKey, byte[] deweyId, LongHashFunction hashFunction,
       ResourceConfiguration config) {
+    // Unbind flyweight - ensures getters use Java fields, not stale page reference
+    this.page = null;
     this.nodeKey = nodeKey;
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyId;
@@ -411,12 +864,12 @@ private static BytesIn createBytesIn(Object source, long offset) {
   }
 
   @Override
-  public long computeHash(BytesOut bytes) {
+  public long computeHash(final BytesOut bytes) {
     if (hashFunction == null)
       return 0L;
     bytes.clear();
-    bytes.writeLong(nodeKey).writeLong(parentKey).writeByte(getKind().getId());
-    bytes.writeInt(prefixKey).writeInt(localNameKey).writeInt(uriKey);
+    bytes.writeLong(getNodeKey()).writeLong(getParentKey()).writeByte(getKind().getId());
+    bytes.writeInt(getPrefixKey()).writeInt(getLocalNameKey()).writeInt(getURIKey());
     final byte[] rawValue = getRawValue();
     if (rawValue != null) {
       bytes.write(rawValue);
@@ -424,48 +877,6 @@ public long computeHash(BytesOut bytes) {
     return bytes.hashDirect(hashFunction);
   }
 
-  public void bindFixedSlotLazy(final MemorySegment slotData, final long baseOffset, final NodeKindLayout layout) {
-    this.lazyBaseOffset = baseOffset;
-    this.fixedSlotLayout = layout;
-    this.metadataParsed = false;
-    // lazyValueSource already points to slotData from setLazyRawValue
-  }
-
-  private void parseMetadataFields() {
-    if (metadataParsed) {
-      return;
-    }
-
-    if (fixedSlotLayout != null) {
-      final MemorySegment sd = (MemorySegment) lazyValueSource;
-      final NodeKindLayout ly = fixedSlotLayout;
-      final long off = this.lazyBaseOffset;
-      this.previousRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.PREVIOUS_REVISION);
-      this.lastModifiedRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.LAST_MODIFIED_REVISION);
-      this.hash = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.HASH);
-      this.pathNodeKey = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.PATH_NODE_KEY);
-      this.fixedSlotLayout = null;
-      this.metadataParsed = true;
-      return;
-    }
-
-    this.metadataParsed = true;
-  }
-
-  public AttributeNode toSnapshot() {
-    if (!metadataParsed)
-      parseMetadataFields();
-    final byte[] rawValue = getRawValue();
-    return new AttributeNode(nodeKey, parentKey, previousRevision, lastModifiedRevision, pathNodeKey, prefixKey,
-        localNameKey, uriKey, hash, rawValue != null
-            ? rawValue.clone()
-            : null,
-        hashFunction, deweyIDBytes != null
-            ? deweyIDBytes.clone()
-            : null,
-        qNm);
-  }
-
   @Override
   public VisitResult acceptVisitor(XmlNodeVisitor visitor) {
     return visitor.visit(ImmutableAttributeNode.of(this));
@@ -473,22 +884,23 @@ public VisitResult acceptVisitor(XmlNodeVisitor visitor) {
 
   @Override
   public int hashCode() {
-    return Objects.hashCode(nodeKey, parentKey, prefixKey, localNameKey, uriKey);
+    return Objects.hashCode(nodeKey, getParentKey(), getPrefixKey(), getLocalNameKey(), getURIKey());
   }
 
   @Override
   public boolean equals(Object obj) {
     if (!(obj instanceof AttributeNode other))
       return false;
-    return nodeKey == other.nodeKey && parentKey == other.parentKey && prefixKey == other.prefixKey
-        && localNameKey == other.localNameKey && uriKey == other.uriKey;
+    return nodeKey == other.nodeKey && getParentKey() == other.getParentKey()
+        && getPrefixKey() == other.getPrefixKey()
+        && getLocalNameKey() == other.getLocalNameKey() && getURIKey() == other.getURIKey();
   }
 
   @Override
   public @NonNull String toString() {
     return MoreObjects.toStringHelper(this)
                       .add("nodeKey", nodeKey)
-                      .add("parentKey", parentKey)
+                      .add("parentKey", getParentKey())
                       .add("qNm", qNm)
                       .add("value", getValue())
                       .toString();
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/xml/CommentNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/xml/CommentNode.java
index d0cbcf05a..bd39ec221 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/xml/CommentNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/xml/CommentNode.java
@@ -42,14 +42,13 @@
 import io.sirix.node.NodeKind;
 import io.sirix.node.SirixDeweyID;
 import io.sirix.node.immutable.xml.ImmutableComment;
+import io.sirix.node.interfaces.FlyweightNode;
 import io.sirix.node.interfaces.Node;
-import io.sirix.node.interfaces.ReusableNodeProxy;
 import io.sirix.node.interfaces.StructNode;
 import io.sirix.node.interfaces.ValueNode;
 import io.sirix.node.interfaces.immutable.ImmutableXmlNode;
-import io.sirix.node.layout.NodeKindLayout;
-import io.sirix.node.layout.SlotLayoutAccessors;
-import io.sirix.node.layout.StructuralField;
+import io.sirix.page.KeyValueLeafPage;
+import io.sirix.page.NodeFieldLayout;
 import io.sirix.settings.Constants;
 import io.sirix.settings.Fixed;
 import io.sirix.utils.Compression;
@@ -59,17 +58,19 @@
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
 
 /**
  * Comment node implementation using primitive fields.
  *
  * 

- * Uses primitive fields for efficient storage.
+ * Uses primitive fields for efficient storage. Supports LeanStore-style flyweight binding
+ * for zero-copy reads from slotted page MemorySegment.
  * 

  *
  * @author Johannes Lichtenberger
  */
-public final class CommentNode implements StructNode, ValueNode, ImmutableXmlNode, ReusableNodeProxy {
+public final class CommentNode implements StructNode, ValueNode, ImmutableXmlNode, FlyweightNode {
 
   // === IMMEDIATE STRUCTURAL FIELDS ===
   private long nodeKey;
@@ -91,16 +92,34 @@ public final class CommentNode implements StructNode, ValueNode, ImmutableXmlNod
   private boolean lazyValueCompressed;
   private boolean valueParsed = true;
 
-  // === METADATA LAZY SUPPORT ===
-  private long lazyBaseOffset;
-  private NodeKindLayout fixedSlotLayout;
-  private boolean metadataParsed = true;
-
   // === NON-SERIALIZED FIELDS ===
   private LongHashFunction hashFunction;
   private SirixDeweyID sirixDeweyID;
   private byte[] deweyIDBytes;
 
+  // ==================== FLYWEIGHT BINDING (LeanStore page-direct access) ====================
+  private MemorySegment page;
+  private long recordBase;
+  private long dataRegionStart;
+  private int slotIndex;
+  private boolean writeSingleton;
+  private KeyValueLeafPage ownerPage;
+  private final int[] heapOffsets;
+  private static final int FIELD_COUNT = NodeFieldLayout.COMMENT_FIELD_COUNT;
+
+  /**
+   * Constructor for flyweight binding.
+   * All fields except nodeKey and hashFunction will be read from page memory after bind().
+   *
+   * @param nodeKey the node key
+   * @param hashFunction the hash function from resource config
+   */
+  public CommentNode(long nodeKey, LongHashFunction hashFunction) {
+    this.nodeKey = nodeKey;
+    this.hashFunction = hashFunction;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
+
   /**
    * Primary constructor with all primitive fields.
    */
@@ -118,6 +137,7 @@ public CommentNode(long nodeKey, long parentKey, int previousRevision, int lastM
     this.isCompressed = isCompressed;
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyID;
+    this.heapOffsets = new int[FIELD_COUNT];
   }
 
   /**
@@ -137,6 +157,208 @@ public CommentNode(long nodeKey, long parentKey, int previousRevision, int lastM
     this.isCompressed = isCompressed;
     this.hashFunction = hashFunction;
     this.sirixDeweyID = deweyID;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
+
+  // ==================== FLYWEIGHT BIND/UNBIND ====================
+
+  @Override
+  public void bind(final MemorySegment page, final long recordBase, final long nodeKey,
+      final int slotIndex) {
+    this.page = page;
+    this.recordBase = recordBase;
+    this.nodeKey = nodeKey;
+    this.slotIndex = slotIndex;
+    this.dataRegionStart = recordBase + 1 + FIELD_COUNT;
+    this.valueParsed = false; // Payload still needs lazy parsing from page
+    this.lazyValueSource = null;
+    this.hash = 0;
+  }
+
+  @Override
+  public void unbind() {
+    if (page == null) return;
+    final long nk = this.nodeKey;
+    this.parentKey = readDeltaField(NodeFieldLayout.COMMENT_PARENT_KEY, nk);
+    this.rightSiblingKey = readDeltaField(NodeFieldLayout.COMMENT_RIGHT_SIB_KEY, nk);
+    this.leftSiblingKey = readDeltaField(NodeFieldLayout.COMMENT_LEFT_SIB_KEY, nk);
+    this.previousRevision = readSignedField(NodeFieldLayout.COMMENT_PREV_REVISION);
+    this.lastModifiedRevision = readSignedField(NodeFieldLayout.COMMENT_LAST_MOD_REVISION);
+    // Hash is not stored on the slotted page; keep current in-memory value
+    // Payload needs to be read from page before unbinding
+    if (!valueParsed) {
+      readPayloadFromPage();
+    }
+    this.ownerPage = null;
+    this.page = null;
+  }
+
+  @Override
+  public void clearBinding() {
+    this.ownerPage = null;
+    this.page = null;
+  }
+
+  @Override
+  public boolean isBound() { return page != null; }
+
+  @Override
+  public boolean isBoundTo(final MemorySegment page) {
+    return this.page == page;
+  }
+
+  @Override
+  public int getSlotIndex() {
+    return slotIndex;
+  }
+
+  @Override public boolean isWriteSingleton() { return writeSingleton; }
+  @Override public void setWriteSingleton(final boolean ws) { this.writeSingleton = ws; }
+  @Override public KeyValueLeafPage getOwnerPage() { return ownerPage; }
+  @Override public void setOwnerPage(final KeyValueLeafPage p) { this.ownerPage = p; }
+
+  @Override
+  public int estimateSerializedSize() {
+    final int payloadLen = value != null ? value.length : 0;
+    return 55 + payloadLen;
+  }
+
+  // ==================== FLYWEIGHT FIELD READ HELPERS ====================
+
+  private long readDeltaField(final int fieldIndex, final long baseKey) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeDeltaFromSegment(page, dataRegionStart + fieldOff, baseKey);
+  }
+
+  private int readSignedField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeSignedFromSegment(page, dataRegionStart + fieldOff);
+  }
+
+  /**
+   * Read the payload (value bytes) directly from page memory when bound.
+   */
+  private void readPayloadFromPage() {
+    final int payloadFieldOff = page.get(ValueLayout.JAVA_BYTE,
+        recordBase + 1 + NodeFieldLayout.COMMENT_PAYLOAD) & 0xFF;
+    final long payloadStart = dataRegionStart + payloadFieldOff;
+
+    // Read isCompressed flag (1 byte)
+    this.isCompressed = page.get(ValueLayout.JAVA_BYTE, payloadStart) == 1;
+
+    // Read value length (varint)
+    final long lenOffset = payloadStart + 1;
+    final int length = DeltaVarIntCodec.decodeSignedFromSegment(page, lenOffset);
+    final int lenBytes = DeltaVarIntCodec.readSignedVarintWidth(page, lenOffset);
+
+    // Read value bytes
+    final long dataOffset = lenOffset + lenBytes;
+    this.value = new byte[length];
+    MemorySegment.copy(page, ValueLayout.JAVA_BYTE, dataOffset, this.value, 0, length);
+    this.valueParsed = true;
+  }
+
+  // ==================== DIRECT WRITE ====================
+
+  /**
+   * Encode a CommentNode record directly to a MemorySegment from parameter values.
+   * Static -- reads nothing from any instance. Zero field intermediation.
+   *
+   * @param target       the target MemorySegment (reinterpreted slotted page)
+   * @param offset       absolute byte offset to write at
+   * @param heapOffsets  pre-allocated offset array (reused, FIELD_COUNT elements)
+   * @param nodeKey      the node key (delta base for structural keys)
+   * @param parentKey    the parent node key
+   * @param rightSibKey  the right sibling key
+   * @param leftSibKey   the left sibling key
+   * @param prevRev      the previous revision number
+   * @param lastModRev   the last modified revision number
+   * @param rawValue     the raw value bytes (possibly compressed)
+   * @param isCompressed whether the value is compressed
+   * @return the total number of bytes written
+   */
+  public static int writeNewRecord(final MemorySegment target, final long offset,
+      final int[] heapOffsets, final long nodeKey,
+      final long parentKey, final long rightSibKey, final long leftSibKey,
+      final int prevRev, final int lastModRev,
+      final byte[] rawValue, final boolean isCompressed) {
+    long pos = offset;
+
+    // Write nodeKind byte
+    target.set(ValueLayout.JAVA_BYTE, pos, NodeKind.COMMENT.getId());
+    pos++;
+
+    // Reserve space for offset table
+    final long offsetTableStart = pos;
+    pos += FIELD_COUNT;
+
+    // Data region start
+    final long dataStart = pos;
+
+    // Field 0: parentKey (delta-varint)
+    heapOffsets[NodeFieldLayout.COMMENT_PARENT_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, parentKey, nodeKey);
+
+    // Field 1: rightSiblingKey (delta-varint)
+    heapOffsets[NodeFieldLayout.COMMENT_RIGHT_SIB_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, rightSibKey, nodeKey);
+
+    // Field 2: leftSiblingKey (delta-varint)
+    heapOffsets[NodeFieldLayout.COMMENT_LEFT_SIB_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, leftSibKey, nodeKey);
+
+    // Field 3: prevRevision (signed varint)
+    heapOffsets[NodeFieldLayout.COMMENT_PREV_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, prevRev);
+
+    // Field 4: lastModRevision (signed varint)
+    heapOffsets[NodeFieldLayout.COMMENT_LAST_MOD_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, lastModRev);
+
+    // Field 5: payload [isCompressed:1][length:varint][data:bytes]
+    heapOffsets[NodeFieldLayout.COMMENT_PAYLOAD] = (int) (pos - dataStart);
+    target.set(ValueLayout.JAVA_BYTE, pos, isCompressed ? (byte) 1 : (byte) 0);
+    pos++;
+    final byte[] val = rawValue != null ? rawValue : new byte[0];
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, val.length);
+    if (val.length > 0) {
+      MemorySegment.copy(val, 0, target, ValueLayout.JAVA_BYTE, pos, val.length);
+      pos += val.length;
+    }
+
+    // Write offset table
+    for (int i = 0; i < FIELD_COUNT; i++) {
+      target.set(ValueLayout.JAVA_BYTE, offsetTableStart + i, (byte) heapOffsets[i]);
+    }
+
+    return (int) (pos - offset);
+  }
+
+  /**
+   * Serialize this node from Java fields. Delegates to static writeNewRecord.
+   */
+  @Override
+  public int serializeToHeap(final MemorySegment target, final long offset) {
+    if (!valueParsed) parseLazyValue();
+    return writeNewRecord(target, offset, heapOffsets, nodeKey,
+        parentKey, rightSiblingKey, leftSiblingKey,
+        previousRevision, lastModifiedRevision, value, isCompressed);
+  }
+
+  /**
+   * Get the pre-allocated heap offsets array for use with static writeNewRecord.
+   */
+  public int[] getHeapOffsets() {
+    return heapOffsets;
+  }
+
+  /**
+   * Set DeweyID fields directly after creation, bypassing write-through.
+   * The DeweyID is already in the page trailer -- this just sets the Java cache fields.
+   */
+  public void setDeweyIDAfterCreation(final SirixDeweyID id, final byte[] bytes) {
+    this.sirixDeweyID = id;
+    this.deweyIDBytes = bytes;
   }
 
   @Override
@@ -156,88 +378,193 @@ public void setNodeKey(long nodeKey) {
 
   @Override
   public long getParentKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.COMMENT_PARENT_KEY, nodeKey);
+    }
     return parentKey;
   }
 
-  public void setParentKey(long parentKey) {
+  public void setParentKey(final long parentKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.COMMENT_PARENT_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(parentKey, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, parentKey, nodeKey);
+        return;
+      }
+      resizeParentKey(parentKey);
+      return;
+    }
     this.parentKey = parentKey;
   }
 
+  private void resizeParentKey(final long parentKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.COMMENT_PARENT_KEY, NodeFieldLayout.COMMENT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, parentKey, nodeKey));
+  }
+
   @Override
   public boolean hasParent() {
-    return parentKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getParentKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public long getRightSiblingKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.COMMENT_RIGHT_SIB_KEY, nodeKey);
+    }
     return rightSiblingKey;
   }
 
-  public void setRightSiblingKey(long key) {
+  public void setRightSiblingKey(final long key) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.COMMENT_RIGHT_SIB_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(key, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, key, nodeKey);
+        return;
+      }
+      resizeRightSiblingKey(key);
+      return;
+    }
     this.rightSiblingKey = key;
   }
 
+  private void resizeRightSiblingKey(final long key) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.COMMENT_RIGHT_SIB_KEY, NodeFieldLayout.COMMENT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, key, nodeKey));
+  }
+
   @Override
   public boolean hasRightSibling() {
-    return rightSiblingKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getRightSiblingKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public long getLeftSiblingKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.COMMENT_LEFT_SIB_KEY, nodeKey);
+    }
     return leftSiblingKey;
   }
 
-  public void setLeftSiblingKey(long key) {
+  public void setLeftSiblingKey(final long key) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.COMMENT_LEFT_SIB_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(key, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, key, nodeKey);
+        return;
+      }
+      resizeLeftSiblingKey(key);
+      return;
+    }
     this.leftSiblingKey = key;
   }
 
+  private void resizeLeftSiblingKey(final long key) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.COMMENT_LEFT_SIB_KEY, NodeFieldLayout.COMMENT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, key, nodeKey));
+  }
+
   @Override
   public boolean hasLeftSibling() {
-    return leftSiblingKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getLeftSiblingKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public int getPreviousRevisionNumber() {
-    if (!metadataParsed)
-      parseMetadataFields();
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.COMMENT_PREV_REVISION);
+    }
     return previousRevision;
   }
 
   @Override
-  public void setPreviousRevision(int revision) {
+  public void setPreviousRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.COMMENT_PREV_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizePreviousRevision(revision);
+      return;
+    }
     this.previousRevision = revision;
   }
 
+  private void resizePreviousRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.COMMENT_PREV_REVISION, NodeFieldLayout.COMMENT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+  }
+
   @Override
   public int getLastModifiedRevisionNumber() {
-    if (!metadataParsed)
-      parseMetadataFields();
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.COMMENT_LAST_MOD_REVISION);
+    }
     return lastModifiedRevision;
   }
 
   @Override
-  public void setLastModifiedRevision(int revision) {
+  public void setLastModifiedRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.COMMENT_LAST_MOD_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizeLastModifiedRevision(revision);
+      return;
+    }
     this.lastModifiedRevision = revision;
   }
 
+  private void resizeLastModifiedRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.COMMENT_LAST_MOD_REVISION, NodeFieldLayout.COMMENT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+  }
+
   @Override
   public long getHash() {
-    if (!metadataParsed)
-      parseMetadataFields();
-    if (hash == 0L && hashFunction != null) {
-      hash = computeHash(Bytes.threadLocalHashBuffer());
+    if (hash != 0L) {
+      return hash;
+    }
+    // Hash not stored on page -- compute on demand from node fields
+    if (hashFunction != null) {
+      return computeHash(Bytes.threadLocalHashBuffer());
     }
-    return hash;
+    return 0L;
   }
 
   @Override
-  public void setHash(long hash) {
+  public void setHash(final long hash) {
     this.hash = hash;
   }
 
   @Override
   public byte[] getRawValue() {
-    if (!valueParsed) {
+    if (page != null && !valueParsed) {
+      readPayloadFromPage();
+    } else if (!valueParsed) {
       parseLazyValue();
     }
     if (value != null && isCompressed) {
@@ -249,6 +576,23 @@ public byte[] getRawValue() {
 
   @Override
   public void setRawValue(byte[] value) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.value = value;
+      this.valueParsed = true;
+      this.lazyValueSource = null;
+      this.lazyValueOffset = 0L;
+      this.lazyValueLength = 0;
+      this.lazyValueCompressed = false;
+      this.isCompressed = false;
+      this.hash = 0L;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
+    if (page != null) unbind();
     this.value = value;
     this.valueParsed = true;
     this.lazyValueSource = null;
@@ -365,6 +709,16 @@ public void setTypeKey(int typeKey) {
 
   @Override
   public void setDeweyID(SirixDeweyID id) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.sirixDeweyID = id;
+      this.deweyIDBytes = null;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
     this.sirixDeweyID = id;
     this.deweyIDBytes = null;
   }
@@ -399,6 +753,8 @@ public LongHashFunction getHashFunction() {
    */
   public void readFrom(BytesIn source, long nodeKey, byte[] deweyId, LongHashFunction hashFunction,
       ResourceConfiguration config) {
+    // Unbind flyweight -- ensures getters use Java fields, not stale page reference
+    this.page = null;
     this.nodeKey = nodeKey;
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyId;
@@ -460,16 +816,55 @@ private static BytesIn createBytesIn(Object source, long offset) {
    * preserve the original compressed bytes.
    */
   public byte[] getRawValueWithoutDecompression() {
-    if (!valueParsed) {
+    if (page != null && !valueParsed) {
+      readPayloadFromPage();
+    } else if (!valueParsed) {
       parseLazyValue();
     }
     return value;
   }
 
   public boolean isCompressed() {
+    if (page != null && !valueParsed) {
+      readPayloadFromPage();
+    }
     return isCompressed;
   }
 
+  /**
+   * Create a deep copy snapshot of this node.
+   * Forces parsing of all lazy fields since snapshot must be independent.
+   */
+  public CommentNode toSnapshot() {
+    if (page != null) {
+      // Bound mode: read all fields from page
+      if (!valueParsed) {
+        readPayloadFromPage();
+      }
+      return new CommentNode(nodeKey,
+          readDeltaField(NodeFieldLayout.COMMENT_PARENT_KEY, nodeKey),
+          readSignedField(NodeFieldLayout.COMMENT_PREV_REVISION),
+          readSignedField(NodeFieldLayout.COMMENT_LAST_MOD_REVISION),
+          readDeltaField(NodeFieldLayout.COMMENT_RIGHT_SIB_KEY, nodeKey),
+          readDeltaField(NodeFieldLayout.COMMENT_LEFT_SIB_KEY, nodeKey),
+          hash,
+          value != null ? value.clone() : null,
+          isCompressed,
+          hashFunction,
+          getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null);
+    }
+    // Force parse lazy value for snapshot (must be complete and independent)
+    if (!valueParsed) {
+      parseLazyValue();
+    }
+    return new CommentNode(nodeKey, parentKey, previousRevision, lastModifiedRevision,
+        rightSiblingKey, leftSiblingKey, hash,
+        value != null ? value.clone() : null,
+        isCompressed,
+        hashFunction,
+        getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null);
+  }
+
   @Override
   public long computeHash(BytesOut bytes) {
     if (hashFunction == null) {
@@ -477,55 +872,11 @@ public long computeHash(BytesOut bytes) {
     }
 
     bytes.clear();
-    bytes.writeLong(nodeKey).writeLong(parentKey).writeByte(NodeKind.COMMENT.getId());
+    bytes.writeLong(nodeKey).writeLong(getParentKey()).writeByte(NodeKind.COMMENT.getId());
 
-    bytes.writeLong(leftSiblingKey).writeLong(rightSiblingKey);
     bytes.writeUtf8(new String(getRawValue(), Constants.DEFAULT_ENCODING));
 
-    final var buffer = ((java.nio.ByteBuffer) bytes.underlyingObject()).rewind();
-    buffer.limit((int) bytes.readLimit());
-
-    return hashFunction.hashBytes(buffer);
-  }
-
-  public void bindFixedSlotLazy(final MemorySegment slotData, final long baseOffset, final NodeKindLayout layout) {
-    this.lazyBaseOffset = baseOffset;
-    this.fixedSlotLayout = layout;
-    this.metadataParsed = false;
-    // lazyValueSource already points to slotData from setLazyRawValue
-  }
-
-  private void parseMetadataFields() {
-    if (metadataParsed) {
-      return;
-    }
-
-    if (fixedSlotLayout != null) {
-      final MemorySegment sd = (MemorySegment) lazyValueSource;
-      final NodeKindLayout ly = fixedSlotLayout;
-      final long off = this.lazyBaseOffset;
-      this.previousRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.PREVIOUS_REVISION);
-      this.lastModifiedRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.LAST_MODIFIED_REVISION);
-      this.hash = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.HASH);
-      this.fixedSlotLayout = null;
-      this.metadataParsed = true;
-      return;
-    }
-
-    this.metadataParsed = true;
-  }
-
-  public CommentNode toSnapshot() {
-    if (!metadataParsed)
-      parseMetadataFields();
-    final byte[] rawValue = getRawValue();
-    return new CommentNode(nodeKey, parentKey, previousRevision, lastModifiedRevision, rightSiblingKey, leftSiblingKey,
-        hash, rawValue != null
-            ? rawValue.clone()
-            : null,
-        isCompressed, hashFunction, deweyIDBytes != null
-            ? deweyIDBytes.clone()
-            : null);
+    return bytes.hashDirect(hashFunction);
   }
 
   @Override
@@ -535,13 +886,13 @@ public VisitResult acceptVisitor(XmlNodeVisitor visitor) {
 
   @Override
   public int hashCode() {
-    return Objects.hashCode(nodeKey, parentKey, getValue());
+    return Objects.hashCode(nodeKey, getParentKey(), getValue());
   }
 
   @Override
   public boolean equals(@Nullable Object obj) {
     if (obj instanceof CommentNode other) {
-      return nodeKey == other.nodeKey && parentKey == other.parentKey
+      return nodeKey == other.nodeKey && getParentKey() == other.getParentKey()
           && java.util.Arrays.equals(getRawValue(), other.getRawValue());
     }
     return false;
@@ -551,9 +902,9 @@ public boolean equals(@Nullable Object obj) {
   public @NonNull String toString() {
     return MoreObjects.toStringHelper(this)
                       .add("nodeKey", nodeKey)
-                      .add("parentKey", parentKey)
-                      .add("rightSiblingKey", rightSiblingKey)
-                      .add("leftSiblingKey", leftSiblingKey)
+                      .add("parentKey", getParentKey())
+                      .add("rightSiblingKey", getRightSiblingKey())
+                      .add("leftSiblingKey", getLeftSiblingKey())
                       .add("value", getValue())
                       .add("compressed", isCompressed)
                       .toString();
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/xml/ElementNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/xml/ElementNode.java
index f90521591..49dc2525d 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/xml/ElementNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/xml/ElementNode.java
@@ -35,24 +35,23 @@
 import io.sirix.access.trx.node.HashType;
 import io.sirix.api.visitor.VisitResult;
 import io.sirix.api.visitor.XmlNodeVisitor;
+import io.sirix.node.ByteArrayBytesIn;
 import io.sirix.node.Bytes;
 import io.sirix.node.BytesIn;
 import io.sirix.node.BytesOut;
 import io.sirix.node.DeltaVarIntCodec;
+import io.sirix.node.MemorySegmentBytesIn;
 import io.sirix.node.NodeKind;
 import io.sirix.node.SirixDeweyID;
 import io.sirix.node.immutable.xml.ImmutableElement;
+import io.sirix.node.interfaces.FlyweightNode;
 import io.sirix.node.interfaces.NameNode;
 import io.sirix.node.interfaces.Node;
-import io.sirix.node.interfaces.ReusableNodeProxy;
 import io.sirix.node.interfaces.StructNode;
 import io.sirix.node.interfaces.immutable.ImmutableXmlNode;
-import io.sirix.node.layout.NodeKindLayout;
-import io.sirix.node.layout.SlotLayoutAccessors;
-import io.sirix.node.layout.StructuralField;
+import io.sirix.page.KeyValueLeafPage;
+import io.sirix.page.NodeFieldLayout;
 import io.sirix.settings.Fixed;
-
-import java.lang.foreign.MemorySegment;
 import io.sirix.utils.NamePageHash;
 import it.unimi.dsi.fastutil.longs.LongArrayList;
 import it.unimi.dsi.fastutil.longs.LongList;
@@ -61,6 +60,8 @@
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
+import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
 import java.util.Collections;
 import java.util.List;
 
@@ -69,11 +70,12 @@
  *
  * 

  * Uses primitive fields for efficient storage with delta+varint encoding.
+ * Implements FlyweightNode for LeanStore-style zero-copy page-direct access.
  * 

  *
  * @author Johannes Lichtenberger
  */
-public final class ElementNode implements StructNode, NameNode, ImmutableXmlNode, ReusableNodeProxy {
+public final class ElementNode implements StructNode, NameNode, ImmutableXmlNode, FlyweightNode {
 
   // === IMMEDIATE STRUCTURAL FIELDS ===
   private long nodeKey;
@@ -104,11 +106,55 @@ public final class ElementNode implements StructNode, NameNode, ImmutableXmlNode
   private LongList namespaceKeys;
   private QNm qNm;
 
-  // Fixed-slot lazy support
+  // Lazy parsing state
   private Object lazySource;
-  private long lazyBaseOffset;
-  private NodeKindLayout fixedSlotLayout;
-  private boolean lazyFieldsParsed = true;
+  private long lazyOffset;
+  private boolean lazyFieldsParsed;
+  private boolean hasHash;
+  private boolean storeChildCount;
+
+  // ==================== FLYWEIGHT BINDING ====================
+
+  /** Page MemorySegment when bound (null = primitive mode). */
+  private MemorySegment page;
+
+  /** Absolute byte offset of this record in the page (after HEAP_START + heapOffset). */
+  private long recordBase;
+
+  /** Absolute byte offset where the data region starts (recordBase + 1 + FIELD_COUNT). */
+  private long dataRegionStart;
+
+  /** Slot index in the page directory (for re-serialization). */
+  private int slotIndex;
+
+  /** True if this node is a factory-managed write singleton (must not be stored in records[]). */
+  private boolean writeSingleton;
+
+  /** Owning page for resize-in-place on varint width changes. */
+  private KeyValueLeafPage ownerPage;
+
+  /** Pre-allocated offset array reused across serializations (zero-alloc hot path). */
+  private final int[] heapOffsets;
+
+  /** Whether the payload (attributeKeys, namespaceKeys) has been parsed from page memory. */
+  private boolean payloadParsed;
+
+  private static final int FIELD_COUNT = NodeFieldLayout.ELEMENT_FIELD_COUNT;
+
+  /**
+   * Constructor for flyweight binding.
+   * All fields except nodeKey and hashFunction will be read from page memory after bind().
+   *
+   * @param nodeKey the node key
+   * @param hashFunction the hash function from resource config
+   */
+  public ElementNode(long nodeKey, LongHashFunction hashFunction) {
+    this.nodeKey = nodeKey;
+    this.hashFunction = hashFunction;
+    this.attributeKeys = new LongArrayList();
+    this.namespaceKeys = new LongArrayList();
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
 
   /**
    * Primary constructor with all primitive fields. Used by deserialization
@@ -142,6 +188,8 @@ public ElementNode(long nodeKey, long parentKey, int previousRevision, int lastM
         ? namespaceKeys
         : new LongArrayList();
     this.qNm = qNm;
+    this.lazyFieldsParsed = true;
+    this.heapOffsets = new int[FIELD_COUNT];
   }
 
   /**
@@ -175,6 +223,421 @@ public ElementNode(long nodeKey, long parentKey, int previousRevision, int lastM
         ? namespaceKeys
         : new LongArrayList();
     this.qNm = qNm;
+    this.lazyFieldsParsed = true;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
+
+  // ==================== FLYWEIGHT BIND/UNBIND ====================
+
+  /**
+   * Bind this node as a flyweight to a page MemorySegment.
+   * When bound, getters/setters read/write directly to page memory via the offset table.
+   * Attribute and namespace keys are eagerly read from the payload region because element
+   * nodes almost always need their attr/ns keys.
+   *
+   * @param page       the page MemorySegment
+   * @param recordBase absolute byte offset of this record in the page
+   * @param nodeKey    the node key (for delta decoding)
+   * @param slotIndex  the slot index in the page directory
+   */
+  @Override
+  public void bind(final MemorySegment page, final long recordBase, final long nodeKey,
+      final int slotIndex) {
+    this.page = page;
+    this.recordBase = recordBase;
+    this.nodeKey = nodeKey;
+    this.slotIndex = slotIndex;
+    this.dataRegionStart = recordBase + 1 + FIELD_COUNT;
+    this.lazyFieldsParsed = true; // No lazy state when bound
+    this.lazySource = null;
+    this.payloadParsed = false;
+    // Eagerly parse payload (attribute/namespace keys) since element nodes always need them
+    ensurePayloadParsed();
+  }
+
+  /**
+   * Unbind from page memory and materialize all fields into Java primitives.
+   * After unbind, the node operates in primitive mode.
+   */
+  @Override
+  public void unbind() {
+    if (page == null) {
+      return;
+    }
+    // Materialize all fields from page to Java primitives
+    final long nk = this.nodeKey;
+    this.parentKey = readDeltaField(NodeFieldLayout.ELEM_PARENT_KEY, nk);
+    this.rightSiblingKey = readDeltaField(NodeFieldLayout.ELEM_RIGHT_SIB_KEY, nk);
+    this.leftSiblingKey = readDeltaField(NodeFieldLayout.ELEM_LEFT_SIB_KEY, nk);
+    this.firstChildKey = readDeltaField(NodeFieldLayout.ELEM_FIRST_CHILD_KEY, nk);
+    this.lastChildKey = readDeltaField(NodeFieldLayout.ELEM_LAST_CHILD_KEY, nk);
+    this.pathNodeKey = readDeltaField(NodeFieldLayout.ELEM_PATH_NODE_KEY, nk);
+    this.prefixKey = readSignedField(NodeFieldLayout.ELEM_PREFIX_KEY);
+    this.localNameKey = readSignedField(NodeFieldLayout.ELEM_LOCAL_NAME_KEY);
+    this.uriKey = readSignedField(NodeFieldLayout.ELEM_URI_KEY);
+    this.previousRevision = readSignedField(NodeFieldLayout.ELEM_PREV_REVISION);
+    this.lastModifiedRevision = readSignedField(NodeFieldLayout.ELEM_LAST_MOD_REVISION);
+    this.hash = readLongField(NodeFieldLayout.ELEM_HASH);
+    this.childCount = readSignedLongField(NodeFieldLayout.ELEM_CHILD_COUNT);
+    this.descendantCount = readSignedLongField(NodeFieldLayout.ELEM_DESCENDANT_COUNT);
+    // Parse payload (attributeKeys, namespaceKeys) if not already parsed
+    ensurePayloadParsed();
+    this.ownerPage = null;
+    this.page = null;
+  }
+
+  @Override
+  public void clearBinding() {
+    this.ownerPage = null;
+    this.page = null;
+  }
+
+  /** Check if this node is bound to a page MemorySegment. */
+  @Override
+  public boolean isBound() {
+    return page != null;
+  }
+
+  @Override
+  public boolean isBoundTo(final MemorySegment page) {
+    return this.page == page;
+  }
+
+  @Override
+  public int getSlotIndex() {
+    return slotIndex;
+  }
+
+  @Override
+  public boolean isWriteSingleton() {
+    return writeSingleton;
+  }
+
+  @Override
+  public void setWriteSingleton(final boolean writeSingleton) {
+    this.writeSingleton = writeSingleton;
+  }
+
+  @Override
+  public KeyValueLeafPage getOwnerPage() {
+    return ownerPage;
+  }
+
+  @Override
+  public void setOwnerPage(final KeyValueLeafPage ownerPage) {
+    this.ownerPage = ownerPage;
+  }
+
+  // ==================== FLYWEIGHT FIELD READ HELPERS ====================
+
+  private long readDeltaField(final int fieldIndex, final long baseKey) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeDeltaFromSegment(page, dataRegionStart + fieldOff, baseKey);
+  }
+
+  private int readSignedField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeSignedFromSegment(page, dataRegionStart + fieldOff);
+  }
+
+  private long readSignedLongField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeSignedLongFromSegment(page, dataRegionStart + fieldOff);
+  }
+
+  private long readLongField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.readLongFromSegment(page, (int) (dataRegionStart + fieldOff));
+  }
+
+  // ==================== PAYLOAD PARSING ====================
+
+  /**
+   * Parse the attribute and namespace key lists from the page payload region if not yet parsed.
+   * When bound, reads from page memory; when unbound, does nothing (already materialized).
+   */
+  private void ensurePayloadParsed() {
+    if (payloadParsed || page == null) {
+      return;
+    }
+    payloadParsed = true;
+
+    final int payloadFieldOff = page.get(ValueLayout.JAVA_BYTE,
+        recordBase + 1 + NodeFieldLayout.ELEM_PAYLOAD) & 0xFF;
+    long pos = dataRegionStart + payloadFieldOff;
+
+    // Read attribute count and keys
+    final int attrCount = DeltaVarIntCodec.decodeSignedFromSegment(page, pos);
+    pos += DeltaVarIntCodec.readSignedVarintWidth(page, pos);
+    if (attributeKeys == null) {
+      attributeKeys = new LongArrayList(attrCount);
+    } else {
+      attributeKeys.clear();
+    }
+    for (int i = 0; i < attrCount; i++) {
+      final long attrKey = DeltaVarIntCodec.decodeDeltaFromSegment(page, pos, nodeKey);
+      final int width = DeltaVarIntCodec.readDeltaEncodedWidth(page, pos);
+      pos += width;
+      attributeKeys.add(attrKey);
+    }
+
+    // Read namespace count and keys
+    final int nsCount = DeltaVarIntCodec.decodeSignedFromSegment(page, pos);
+    pos += DeltaVarIntCodec.readSignedVarintWidth(page, pos);
+    if (namespaceKeys == null) {
+      namespaceKeys = new LongArrayList(nsCount);
+    } else {
+      namespaceKeys.clear();
+    }
+    for (int i = 0; i < nsCount; i++) {
+      final long nsKey = DeltaVarIntCodec.decodeDeltaFromSegment(page, pos, nodeKey);
+      final int width = DeltaVarIntCodec.readDeltaEncodedWidth(page, pos);
+      pos += width;
+      namespaceKeys.add(nsKey);
+    }
+  }
+
+  // ==================== DIRECT WRITE ====================
+
+  /**
+   * Encode an ElementNode record directly to a MemorySegment from parameter values.
+   * Static -- reads nothing from any instance. Zero field intermediation.
+   * At creation time, attribute and namespace lists are always empty.
+   *
+   * @param target          the target MemorySegment (reinterpreted slotted page)
+   * @param offset          absolute byte offset to write at
+   * @param heapOffsets     pre-allocated offset array (reused, FIELD_COUNT elements)
+   * @param nodeKey         the node key (delta base for structural keys)
+   * @param parentKey       the parent node key
+   * @param rightSibKey     the right sibling key
+   * @param leftSibKey      the left sibling key
+   * @param firstChildKey   the first child key
+   * @param lastChildKey    the last child key
+   * @param pathNodeKey     the path node key
+   * @param prefixKey       the prefix key
+   * @param localNameKey    the local name key
+   * @param uriKey          the URI key
+   * @param prevRev         the previous revision number
+   * @param lastModRev      the last modified revision number
+   * @param hash            the hash value
+   * @param childCount      the child count
+   * @param descendantCount the descendant count
+   * @return the total number of bytes written
+   */
+  public static int writeNewRecord(final MemorySegment target, final long offset,
+      final int[] heapOffsets, final long nodeKey,
+      final long parentKey, final long rightSibKey, final long leftSibKey,
+      final long firstChildKey, final long lastChildKey,
+      final long pathNodeKey, final int prefixKey, final int localNameKey, final int uriKey,
+      final int prevRev, final int lastModRev, final long hash,
+      final long childCount, final long descendantCount) {
+    long pos = offset;
+
+    // Write nodeKind byte
+    target.set(ValueLayout.JAVA_BYTE, pos, NodeKind.ELEMENT.getId());
+    pos++;
+
+    // Reserve space for offset table
+    final long offsetTableStart = pos;
+    pos += FIELD_COUNT;
+
+    // Data region start
+    final long dataStart = pos;
+
+    // Field 0: parentKey (delta-varint)
+    heapOffsets[NodeFieldLayout.ELEM_PARENT_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, parentKey, nodeKey);
+
+    // Field 1: rightSiblingKey (delta-varint)
+    heapOffsets[NodeFieldLayout.ELEM_RIGHT_SIB_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, rightSibKey, nodeKey);
+
+    // Field 2: leftSiblingKey (delta-varint)
+    heapOffsets[NodeFieldLayout.ELEM_LEFT_SIB_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, leftSibKey, nodeKey);
+
+    // Field 3: firstChildKey (delta-varint)
+    heapOffsets[NodeFieldLayout.ELEM_FIRST_CHILD_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, firstChildKey, nodeKey);
+
+    // Field 4: lastChildKey (delta-varint)
+    heapOffsets[NodeFieldLayout.ELEM_LAST_CHILD_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, lastChildKey, nodeKey);
+
+    // Field 5: pathNodeKey (delta-varint)
+    heapOffsets[NodeFieldLayout.ELEM_PATH_NODE_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, pathNodeKey, nodeKey);
+
+    // Field 6: prefixKey (signed varint)
+    heapOffsets[NodeFieldLayout.ELEM_PREFIX_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, prefixKey);
+
+    // Field 7: localNameKey (signed varint)
+    heapOffsets[NodeFieldLayout.ELEM_LOCAL_NAME_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, localNameKey);
+
+    // Field 8: uriKey (signed varint)
+    heapOffsets[NodeFieldLayout.ELEM_URI_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, uriKey);
+
+    // Field 9: previousRevision (signed varint)
+    heapOffsets[NodeFieldLayout.ELEM_PREV_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, prevRev);
+
+    // Field 10: lastModifiedRevision (signed varint)
+    heapOffsets[NodeFieldLayout.ELEM_LAST_MOD_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, lastModRev);
+
+    // Field 11: hash (fixed 8 bytes)
+    heapOffsets[NodeFieldLayout.ELEM_HASH] = (int) (pos - dataStart);
+    DeltaVarIntCodec.writeLongToSegment(target, pos, hash);
+    pos += Long.BYTES;
+
+    // Field 12: childCount (signed long varint)
+    heapOffsets[NodeFieldLayout.ELEM_CHILD_COUNT] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedLongToSegment(target, pos, childCount);
+
+    // Field 13: descendantCount (signed long varint)
+    heapOffsets[NodeFieldLayout.ELEM_DESCENDANT_COUNT] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedLongToSegment(target, pos, descendantCount);
+
+    // Field 14: PAYLOAD -- at creation, attribute and namespace lists are always empty
+    heapOffsets[NodeFieldLayout.ELEM_PAYLOAD] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, 0); // attrCount = 0
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, 0); // nsCount = 0
+
+    // Write offset table
+    for (int i = 0; i < FIELD_COUNT; i++) {
+      target.set(ValueLayout.JAVA_BYTE, offsetTableStart + i, (byte) heapOffsets[i]);
+    }
+
+    return (int) (pos - offset);
+  }
+
+  /**
+   * Serialize this node from Java fields. Delegates to static writeNewRecord for structural fields,
+   * but writes the full payload (attribute/namespace keys) inline since writeNewRecord only writes
+   * empty lists.
+   */
+  @Override
+  public int serializeToHeap(final MemorySegment target, final long offset) {
+    // Ensure all lazy fields are materialized
+    if (!lazyFieldsParsed) {
+      parseLazyFields();
+    }
+
+    long pos = offset;
+
+    // Write nodeKind byte
+    target.set(ValueLayout.JAVA_BYTE, pos, NodeKind.ELEMENT.getId());
+    pos++;
+
+    // Reserve space for offset table
+    final long offsetTableStart = pos;
+    pos += FIELD_COUNT;
+
+    // Data region start
+    final long dataStart = pos;
+    final int[] offsets = this.heapOffsets;
+
+    // Field 0: parentKey (delta-varint)
+    offsets[NodeFieldLayout.ELEM_PARENT_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, parentKey, nodeKey);
+
+    // Field 1: rightSiblingKey (delta-varint)
+    offsets[NodeFieldLayout.ELEM_RIGHT_SIB_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, rightSiblingKey, nodeKey);
+
+    // Field 2: leftSiblingKey (delta-varint)
+    offsets[NodeFieldLayout.ELEM_LEFT_SIB_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, leftSiblingKey, nodeKey);
+
+    // Field 3: firstChildKey (delta-varint)
+    offsets[NodeFieldLayout.ELEM_FIRST_CHILD_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, firstChildKey, nodeKey);
+
+    // Field 4: lastChildKey (delta-varint)
+    offsets[NodeFieldLayout.ELEM_LAST_CHILD_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, lastChildKey, nodeKey);
+
+    // Field 5: pathNodeKey (delta-varint)
+    offsets[NodeFieldLayout.ELEM_PATH_NODE_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, pathNodeKey, nodeKey);
+
+    // Field 6: prefixKey (signed varint)
+    offsets[NodeFieldLayout.ELEM_PREFIX_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, prefixKey);
+
+    // Field 7: localNameKey (signed varint)
+    offsets[NodeFieldLayout.ELEM_LOCAL_NAME_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, localNameKey);
+
+    // Field 8: uriKey (signed varint)
+    offsets[NodeFieldLayout.ELEM_URI_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, uriKey);
+
+    // Field 9: previousRevision (signed varint)
+    offsets[NodeFieldLayout.ELEM_PREV_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, previousRevision);
+
+    // Field 10: lastModifiedRevision (signed varint)
+    offsets[NodeFieldLayout.ELEM_LAST_MOD_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, lastModifiedRevision);
+
+    // Field 11: hash (fixed 8 bytes)
+    offsets[NodeFieldLayout.ELEM_HASH] = (int) (pos - dataStart);
+    DeltaVarIntCodec.writeLongToSegment(target, pos, hash);
+    pos += Long.BYTES;
+
+    // Field 12: childCount (signed long varint)
+    offsets[NodeFieldLayout.ELEM_CHILD_COUNT] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedLongToSegment(target, pos, childCount);
+
+    // Field 13: descendantCount (signed long varint)
+    offsets[NodeFieldLayout.ELEM_DESCENDANT_COUNT] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedLongToSegment(target, pos, descendantCount);
+
+    // Field 14: PAYLOAD [attrCount:signed varint][attrKeys:delta...][nsCount:signed varint][nsKeys:delta...]
+    offsets[NodeFieldLayout.ELEM_PAYLOAD] = (int) (pos - dataStart);
+    final int attrCount = attributeKeys != null ? attributeKeys.size() : 0;
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, attrCount);
+    for (int i = 0; i < attrCount; i++) {
+      pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, attributeKeys.getLong(i), nodeKey);
+    }
+    final int nsCount = namespaceKeys != null ? namespaceKeys.size() : 0;
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, nsCount);
+    for (int i = 0; i < nsCount; i++) {
+      pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, namespaceKeys.getLong(i), nodeKey);
+    }
+
+    // Write offset table
+    for (int i = 0; i < FIELD_COUNT; i++) {
+      target.set(ValueLayout.JAVA_BYTE, offsetTableStart + i, (byte) offsets[i]);
+    }
+
+    return (int) (pos - offset);
+  }
+
+  /**
+   * Get the pre-allocated heap offsets array for use with static writeNewRecord.
+   */
+  public int[] getHeapOffsets() {
+    return heapOffsets;
+  }
+
+  /**
+   * Set DeweyID fields directly after creation, bypassing write-through.
+   * The DeweyID is already in the page trailer -- this just sets the Java cache fields.
+   */
+  public void setDeweyIDAfterCreation(final SirixDeweyID id, final byte[] bytes) {
+    this.sirixDeweyID = id;
+    this.deweyIDBytes = bytes;
+  }
+
+  @Override
+  public int estimateSerializedSize() {
+    return 128 + (attributeKeys != null ? attributeKeys.size() * 10 : 0)
+        + (namespaceKeys != null ? namespaceKeys.size() * 10 : 0);
   }
 
   @Override
@@ -192,179 +655,459 @@ public void setNodeKey(long nodeKey) {
     this.nodeKey = nodeKey;
   }
 
-  // === IMMEDIATE STRUCTURAL GETTERS (no lazy parsing) ===
+  // === IMMEDIATE STRUCTURAL GETTERS (dual-mode: page or Java field) ===
 
   @Override
   public long getParentKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.ELEM_PARENT_KEY, nodeKey);
+    }
     return parentKey;
   }
 
-  public void setParentKey(long parentKey) {
+  public void setParentKey(final long parentKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.ELEM_PARENT_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(parentKey, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, parentKey, nodeKey);
+        return;
+      }
+      resizeParentKey(parentKey);
+      return;
+    }
     this.parentKey = parentKey;
   }
 
+  private void resizeParentKey(final long parentKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ELEM_PARENT_KEY, NodeFieldLayout.ELEMENT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, parentKey, nodeKey));
+  }
+
   @Override
   public boolean hasParent() {
-    return parentKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getParentKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public long getRightSiblingKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.ELEM_RIGHT_SIB_KEY, nodeKey);
+    }
     return rightSiblingKey;
   }
 
-  public void setRightSiblingKey(long rightSibling) {
+  public void setRightSiblingKey(final long rightSibling) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.ELEM_RIGHT_SIB_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(rightSibling, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, rightSibling, nodeKey);
+        return;
+      }
+      resizeRightSiblingKey(rightSibling);
+      return;
+    }
     this.rightSiblingKey = rightSibling;
   }
 
+  private void resizeRightSiblingKey(final long rightSibling) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ELEM_RIGHT_SIB_KEY, NodeFieldLayout.ELEMENT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, rightSibling, nodeKey));
+  }
+
   @Override
   public boolean hasRightSibling() {
-    return rightSiblingKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getRightSiblingKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public long getLeftSiblingKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.ELEM_LEFT_SIB_KEY, nodeKey);
+    }
     return leftSiblingKey;
   }
 
-  public void setLeftSiblingKey(long leftSibling) {
+  public void setLeftSiblingKey(final long leftSibling) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.ELEM_LEFT_SIB_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(leftSibling, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, leftSibling, nodeKey);
+        return;
+      }
+      resizeLeftSiblingKey(leftSibling);
+      return;
+    }
     this.leftSiblingKey = leftSibling;
   }
 
+  private void resizeLeftSiblingKey(final long leftSibling) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ELEM_LEFT_SIB_KEY, NodeFieldLayout.ELEMENT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, leftSibling, nodeKey));
+  }
+
   @Override
   public boolean hasLeftSibling() {
-    return leftSiblingKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getLeftSiblingKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public long getFirstChildKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.ELEM_FIRST_CHILD_KEY, nodeKey);
+    }
     return firstChildKey;
   }
 
-  public void setFirstChildKey(long firstChild) {
+  public void setFirstChildKey(final long firstChild) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.ELEM_FIRST_CHILD_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(firstChild, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, firstChild, nodeKey);
+        return;
+      }
+      resizeFirstChildKey(firstChild);
+      return;
+    }
     this.firstChildKey = firstChild;
   }
 
+  private void resizeFirstChildKey(final long firstChild) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ELEM_FIRST_CHILD_KEY, NodeFieldLayout.ELEMENT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, firstChild, nodeKey));
+  }
+
   @Override
   public boolean hasFirstChild() {
-    return firstChildKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getFirstChildKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public long getLastChildKey() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.ELEM_LAST_CHILD_KEY, nodeKey);
+    }
     return lastChildKey;
   }
 
-  public void setLastChildKey(long lastChild) {
+  public void setLastChildKey(final long lastChild) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.ELEM_LAST_CHILD_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(lastChild, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, lastChild, nodeKey);
+        return;
+      }
+      resizeLastChildKey(lastChild);
+      return;
+    }
     this.lastChildKey = lastChild;
   }
 
+  private void resizeLastChildKey(final long lastChild) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ELEM_LAST_CHILD_KEY, NodeFieldLayout.ELEMENT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, lastChild, nodeKey));
+  }
+
   @Override
   public boolean hasLastChild() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
-    return lastChildKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getLastChildKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
-  // === METADATA/NAME GETTERS ===
+  // === METADATA/NAME GETTERS (dual-mode) ===
 
   @Override
   public long getPathNodeKey() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.ELEM_PATH_NODE_KEY, nodeKey);
+    }
     return pathNodeKey;
   }
 
   @Override
   public void setPathNodeKey(@NonNegative long pathNodeKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.ELEM_PATH_NODE_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(pathNodeKey, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, pathNodeKey, nodeKey);
+        return;
+      }
+      resizePathNodeKey(pathNodeKey);
+      return;
+    }
     this.pathNodeKey = pathNodeKey;
   }
 
+  private void resizePathNodeKey(final long pathNodeKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ELEM_PATH_NODE_KEY, NodeFieldLayout.ELEMENT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, pathNodeKey, nodeKey));
+  }
+
   @Override
   public int getPrefixKey() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.ELEM_PREFIX_KEY);
+    }
     return prefixKey;
   }
 
   @Override
   public void setPrefixKey(int prefixKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.ELEM_PREFIX_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(prefixKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, prefixKey);
+        return;
+      }
+      resizePrefixKey(prefixKey);
+      return;
+    }
     this.prefixKey = prefixKey;
   }
 
+  private void resizePrefixKey(final int prefixKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ELEM_PREFIX_KEY, NodeFieldLayout.ELEMENT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, prefixKey));
+  }
+
   @Override
   public int getLocalNameKey() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.ELEM_LOCAL_NAME_KEY);
+    }
     return localNameKey;
   }
 
   @Override
   public void setLocalNameKey(int localNameKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.ELEM_LOCAL_NAME_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(localNameKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, localNameKey);
+        return;
+      }
+      resizeLocalNameKey(localNameKey);
+      return;
+    }
     this.localNameKey = localNameKey;
   }
 
+  private void resizeLocalNameKey(final int localNameKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ELEM_LOCAL_NAME_KEY, NodeFieldLayout.ELEMENT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, localNameKey));
+  }
+
   @Override
   public int getURIKey() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.ELEM_URI_KEY);
+    }
     return uriKey;
   }
 
   @Override
   public void setURIKey(int uriKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.ELEM_URI_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(uriKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, uriKey);
+        return;
+      }
+      resizeURIKey(uriKey);
+      return;
+    }
     this.uriKey = uriKey;
   }
 
+  private void resizeURIKey(final int uriKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ELEM_URI_KEY, NodeFieldLayout.ELEMENT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, uriKey));
+  }
+
   @Override
   public int getPreviousRevisionNumber() {
-    if (!lazyFieldsParsed)
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.ELEM_PREV_REVISION);
+    }
+    if (!lazyFieldsParsed) {
       parseLazyFields();
+    }
     return previousRevision;
   }
 
   @Override
   public void setPreviousRevision(int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.ELEM_PREV_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizePreviousRevision(revision);
+      return;
+    }
     this.previousRevision = revision;
   }
 
+  private void resizePreviousRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ELEM_PREV_REVISION, NodeFieldLayout.ELEMENT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+  }
+
   @Override
   public int getLastModifiedRevisionNumber() {
-    if (!lazyFieldsParsed)
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.ELEM_LAST_MOD_REVISION);
+    }
+    if (!lazyFieldsParsed) {
       parseLazyFields();
+    }
     return lastModifiedRevision;
   }
 
   @Override
   public void setLastModifiedRevision(int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.ELEM_LAST_MOD_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizeLastModifiedRevision(revision);
+      return;
+    }
     this.lastModifiedRevision = revision;
   }
 
+  private void resizeLastModifiedRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ELEM_LAST_MOD_REVISION, NodeFieldLayout.ELEMENT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+  }
+
   @Override
   public long getChildCount() {
-    if (!lazyFieldsParsed)
+    if (page != null) {
+      return readSignedLongField(NodeFieldLayout.ELEM_CHILD_COUNT);
+    }
+    if (!lazyFieldsParsed) {
       parseLazyFields();
+    }
     return childCount;
   }
 
-  public void setChildCount(long childCount) {
+  public void setChildCount(final long childCount) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.ELEM_CHILD_COUNT) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedLongEncodedWidth(childCount);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedLongToSegment(page, absOff, childCount);
+        return;
+      }
+      resizeChildCount(childCount);
+      return;
+    }
     this.childCount = childCount;
   }
 
+  private void resizeChildCount(final long childCount) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ELEM_CHILD_COUNT, NodeFieldLayout.ELEMENT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedLongToSegment(target, off, childCount));
+  }
+
   @Override
   public long getDescendantCount() {
-    if (!lazyFieldsParsed)
+    if (page != null) {
+      return readSignedLongField(NodeFieldLayout.ELEM_DESCENDANT_COUNT);
+    }
+    if (!lazyFieldsParsed) {
       parseLazyFields();
+    }
     return descendantCount;
   }
 
   @Override
   public void setDescendantCount(long descendantCount) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.ELEM_DESCENDANT_COUNT) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedLongEncodedWidth(descendantCount);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedLongToSegment(page, absOff, descendantCount);
+        return;
+      }
+      resizeDescendantCount(descendantCount);
+      return;
+    }
     this.descendantCount = descendantCount;
   }
 
+  private void resizeDescendantCount(final long descendantCount) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.ELEM_DESCENDANT_COUNT, NodeFieldLayout.ELEMENT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedLongToSegment(target, off, descendantCount));
+  }
+
   @Override
   public long getHash() {
-    if (!lazyFieldsParsed)
+    if (page != null) {
+      final long h = readLongField(NodeFieldLayout.ELEM_HASH);
+      if (h != 0L) return h;
+      if (hashFunction != null) {
+        final long computed = computeHash(Bytes.threadLocalHashBuffer());
+        setHash(computed);
+        return computed;
+      }
+      return 0L;
+    }
+    if (!lazyFieldsParsed) {
       parseLazyFields();
+    }
     if (hash == 0L && hashFunction != null) {
       hash = computeHash(Bytes.threadLocalHashBuffer());
     }
@@ -372,36 +1115,35 @@ public long getHash() {
   }
 
   @Override
-  public void setHash(long hash) {
+  public void setHash(final long hash) {
+    if (page != null) {
+      // Hash is ALWAYS in-place (fixed 8 bytes)
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.ELEM_HASH) & 0xFF;
+      DeltaVarIntCodec.writeLongToSegment(page, dataRegionStart + fieldOff, hash);
+      return;
+    }
     this.hash = hash;
   }
 
   @Override
   public void incrementChildCount() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
-    childCount++;
+    setChildCount(getChildCount() + 1);
   }
 
   @Override
   public void decrementChildCount() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
-    childCount--;
+    setChildCount(getChildCount() - 1);
   }
 
   @Override
   public void incrementDescendantCount() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
-    descendantCount++;
+    setDescendantCount(getDescendantCount() + 1);
   }
 
   @Override
   public void decrementDescendantCount() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
-    descendantCount--;
+    setDescendantCount(getDescendantCount() - 1);
   }
 
   // === NON-SERIALIZED FIELD ACCESSORS ===
@@ -432,6 +1174,16 @@ public void setTypeKey(int typeKey) {
 
   @Override
   public void setDeweyID(SirixDeweyID id) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.sirixDeweyID = id;
+      this.deweyIDBytes = null;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
     this.sirixDeweyID = id;
     this.deweyIDBytes = null;
   }
@@ -461,13 +1213,19 @@ public LongHashFunction getHashFunction() {
     return hashFunction;
   }
 
-  // === ATTRIBUTE METHODS ===
+  // === ATTRIBUTE METHODS (dual-mode) ===
 
   public int getAttributeCount() {
+    if (page != null) {
+      ensurePayloadParsed();
+    }
     return attributeKeys.size();
   }
 
   public long getAttributeKey(@NonNegative int index) {
+    if (page != null) {
+      ensurePayloadParsed();
+    }
     if (attributeKeys.size() <= index) {
       return Fixed.NULL_NODE_KEY.getStandardProperty();
     }
@@ -475,28 +1233,50 @@ public long getAttributeKey(@NonNegative int index) {
   }
 
   public void insertAttribute(@NonNegative long attrKey) {
+    if (page != null) {
+      ensurePayloadParsed();
+      // Payload changed: must unbind and re-serialize
+      unbind();
+    }
     attributeKeys.add(attrKey);
   }
 
   public void removeAttribute(@NonNegative long attrNodeKey) {
+    if (page != null) {
+      ensurePayloadParsed();
+      unbind();
+    }
     attributeKeys.removeIf(key -> key == attrNodeKey);
   }
 
   public void clearAttributeKeys() {
+    if (page != null) {
+      ensurePayloadParsed();
+      unbind();
+    }
     attributeKeys.clear();
   }
 
   public List getAttributeKeys() {
+    if (page != null) {
+      ensurePayloadParsed();
+    }
     return Collections.unmodifiableList(attributeKeys);
   }
 
-  // === NAMESPACE METHODS ===
+  // === NAMESPACE METHODS (dual-mode) ===
 
   public int getNamespaceCount() {
+    if (page != null) {
+      ensurePayloadParsed();
+    }
     return namespaceKeys.size();
   }
 
   public long getNamespaceKey(@NonNegative int namespaceKey) {
+    if (page != null) {
+      ensurePayloadParsed();
+    }
     if (namespaceKeys.size() <= namespaceKey) {
       return Fixed.NULL_NODE_KEY.getStandardProperty();
     }
@@ -504,18 +1284,33 @@ public long getNamespaceKey(@NonNegative int namespaceKey) {
   }
 
   public void insertNamespace(long namespaceKey) {
+    if (page != null) {
+      ensurePayloadParsed();
+      unbind();
+    }
     namespaceKeys.add(namespaceKey);
   }
 
   public void removeNamespace(long namespaceKey) {
+    if (page != null) {
+      ensurePayloadParsed();
+      unbind();
+    }
     namespaceKeys.removeIf(key -> key == namespaceKey);
   }
 
   public void clearNamespaceKeys() {
+    if (page != null) {
+      ensurePayloadParsed();
+      unbind();
+    }
     namespaceKeys.clear();
   }
 
   public List getNamespaceKeys() {
+    if (page != null) {
+      ensurePayloadParsed();
+    }
     return Collections.unmodifiableList(namespaceKeys);
   }
 
@@ -547,13 +1342,17 @@ public long computeHash(BytesOut bytes) {
 
   /**
    * Populate this node from a BytesIn source for singleton reuse.
+   * LAZY OPTIMIZATION: Only parses structural fields immediately (NEW ORDER).
    */
   public void readFrom(BytesIn source, long nodeKey, byte[] deweyId, LongHashFunction hashFunction,
       ResourceConfiguration config) {
+    // Unbind flyweight -- ensures getters use Java fields, not stale page reference
+    this.page = null;
     this.nodeKey = nodeKey;
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyId;
     this.sirixDeweyID = null;
+    this.payloadParsed = false;
     if (this.attributeKeys == null) {
       this.attributeKeys = new LongArrayList();
     }
@@ -572,35 +1371,19 @@ public void readFrom(BytesIn source, long nodeKey, byte[] deweyId, LongHashFu
     this.prefixKey = DeltaVarIntCodec.decodeSigned(source);
     this.localNameKey = DeltaVarIntCodec.decodeSigned(source);
     this.uriKey = DeltaVarIntCodec.decodeSigned(source);
-    this.previousRevision = DeltaVarIntCodec.decodeSigned(source);
-    this.lastModifiedRevision = DeltaVarIntCodec.decodeSigned(source);
-    this.childCount = config.storeChildCount()
-        ? DeltaVarIntCodec.decodeSigned(source)
-        : 0L;
-    if (config.hashType != HashType.NONE) {
-      this.hash = source.readLong();
-      this.descendantCount = DeltaVarIntCodec.decodeSigned(source);
-    } else {
-      this.hash = 0L;
-      this.descendantCount = 0L;
-    }
-
-    final int attributeCount = DeltaVarIntCodec.decodeSigned(source);
-    for (int i = 0; i < attributeCount; i++) {
-      this.attributeKeys.add(DeltaVarIntCodec.decodeDelta(source, nodeKey));
-    }
-
-    final int namespaceCount = DeltaVarIntCodec.decodeSigned(source);
-    for (int i = 0; i < namespaceCount; i++) {
-      this.namespaceKeys.add(DeltaVarIntCodec.decodeDelta(source, nodeKey));
-    }
-  }
 
-  public void bindFixedSlotLazy(final MemorySegment slotData, final long baseOffset, final NodeKindLayout layout) {
-    this.lazyBaseOffset = baseOffset;
-    this.lazySource = slotData;
-    this.fixedSlotLayout = layout;
+    // Store for lazy parsing of remaining fields
+    this.lazySource = source.getSource();
+    this.lazyOffset = source.position();
     this.lazyFieldsParsed = false;
+    this.hasHash = config.hashType != HashType.NONE;
+    this.storeChildCount = config.storeChildCount();
+
+    this.previousRevision = 0;
+    this.lastModifiedRevision = 0;
+    this.childCount = 0;
+    this.hash = 0;
+    this.descendantCount = 0;
   }
 
   private void parseLazyFields() {
@@ -608,38 +1391,99 @@ private void parseLazyFields() {
       return;
     }
 
-    if (fixedSlotLayout != null) {
-      final MemorySegment sd = (MemorySegment) lazySource;
-      final NodeKindLayout ly = fixedSlotLayout;
-      final long off = this.lazyBaseOffset;
-      this.previousRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.PREVIOUS_REVISION);
-      this.lastModifiedRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.LAST_MODIFIED_REVISION);
-      this.lastChildKey = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.LAST_CHILD_KEY);
-      this.childCount = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.CHILD_COUNT);
-      this.descendantCount = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.DESCENDANT_COUNT);
-      this.hash = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.HASH);
-      this.pathNodeKey = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.PATH_NODE_KEY);
-      this.uriKey = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.URI_KEY);
-      this.fixedSlotLayout = null;
-      this.lazyFieldsParsed = true;
+    if (lazySource == null) {
+      lazyFieldsParsed = true;
       return;
     }
 
+    BytesIn bytesIn;
+    if (lazySource instanceof MemorySegment segment) {
+      bytesIn = new MemorySegmentBytesIn(segment);
+      bytesIn.position(lazyOffset);
+    } else if (lazySource instanceof byte[] bytes) {
+      bytesIn = new ByteArrayBytesIn(bytes);
+      bytesIn.position(lazyOffset);
+    } else {
+      throw new IllegalStateException("Unknown lazy source type: " + lazySource.getClass());
+    }
+
+    this.previousRevision = DeltaVarIntCodec.decodeSigned(bytesIn);
+    this.lastModifiedRevision = DeltaVarIntCodec.decodeSigned(bytesIn);
+    this.childCount = storeChildCount
+        ? DeltaVarIntCodec.decodeSigned(bytesIn)
+        : 0L;
+    if (hasHash) {
+      this.hash = bytesIn.readLong();
+      this.descendantCount = DeltaVarIntCodec.decodeSigned(bytesIn);
+    } else {
+      this.hash = 0L;
+      this.descendantCount = 0L;
+    }
+
+    final int attributeCount = DeltaVarIntCodec.decodeSigned(bytesIn);
+    for (int i = 0; i < attributeCount; i++) {
+      this.attributeKeys.add(DeltaVarIntCodec.decodeDelta(bytesIn, nodeKey));
+    }
+
+    final int namespaceCount = DeltaVarIntCodec.decodeSigned(bytesIn);
+    for (int i = 0; i < namespaceCount; i++) {
+      this.namespaceKeys.add(DeltaVarIntCodec.decodeDelta(bytesIn, nodeKey));
+    }
+
     this.lazyFieldsParsed = true;
   }
 
   /**
    * Create a deep copy snapshot of this node.
+   *
+   * @return a new instance with copied values
    */
   public ElementNode toSnapshot() {
-    if (!lazyFieldsParsed)
+    if (page != null) {
+      final long nk = this.nodeKey;
+      ensurePayloadParsed();
+      final ElementNode snapshot = new ElementNode(
+          nk,
+          readDeltaField(NodeFieldLayout.ELEM_PARENT_KEY, nk),
+          readSignedField(NodeFieldLayout.ELEM_PREV_REVISION),
+          readSignedField(NodeFieldLayout.ELEM_LAST_MOD_REVISION),
+          readDeltaField(NodeFieldLayout.ELEM_RIGHT_SIB_KEY, nk),
+          readDeltaField(NodeFieldLayout.ELEM_LEFT_SIB_KEY, nk),
+          readDeltaField(NodeFieldLayout.ELEM_FIRST_CHILD_KEY, nk),
+          readDeltaField(NodeFieldLayout.ELEM_LAST_CHILD_KEY, nk),
+          readSignedLongField(NodeFieldLayout.ELEM_CHILD_COUNT),
+          readSignedLongField(NodeFieldLayout.ELEM_DESCENDANT_COUNT),
+          readLongField(NodeFieldLayout.ELEM_HASH),
+          readDeltaField(NodeFieldLayout.ELEM_PATH_NODE_KEY, nk),
+          readSignedField(NodeFieldLayout.ELEM_PREFIX_KEY),
+          readSignedField(NodeFieldLayout.ELEM_LOCAL_NAME_KEY),
+          readSignedField(NodeFieldLayout.ELEM_URI_KEY),
+          hashFunction,
+          getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null,
+          new LongArrayList(attributeKeys),
+          new LongArrayList(namespaceKeys),
+          qNm);
+      if (sirixDeweyID != null) {
+        snapshot.sirixDeweyID = sirixDeweyID;
+      }
+      return snapshot;
+    }
+    if (!lazyFieldsParsed) {
       parseLazyFields();
-    return new ElementNode(nodeKey, parentKey, previousRevision, lastModifiedRevision, rightSiblingKey, leftSiblingKey,
-        firstChildKey, lastChildKey, childCount, descendantCount, hash, pathNodeKey, prefixKey, localNameKey, uriKey,
-        hashFunction, deweyIDBytes != null
-            ? deweyIDBytes.clone()
-            : null,
-        new LongArrayList(attributeKeys), new LongArrayList(namespaceKeys), qNm);
+    }
+    final ElementNode snapshot = new ElementNode(
+        nodeKey, parentKey, previousRevision, lastModifiedRevision,
+        rightSiblingKey, leftSiblingKey, firstChildKey, lastChildKey,
+        childCount, descendantCount, hash, pathNodeKey,
+        prefixKey, localNameKey, uriKey, hashFunction,
+        getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null,
+        new LongArrayList(attributeKeys),
+        new LongArrayList(namespaceKeys),
+        qNm);
+    if (sirixDeweyID != null) {
+      snapshot.sirixDeweyID = sirixDeweyID;
+    }
+    return snapshot;
   }
 
   @Override
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/xml/NamespaceNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/xml/NamespaceNode.java
index e6ff591e4..efa5e1129 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/xml/NamespaceNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/xml/NamespaceNode.java
@@ -34,35 +34,39 @@
 import io.sirix.access.ResourceConfiguration;
 import io.sirix.api.visitor.VisitResult;
 import io.sirix.api.visitor.XmlNodeVisitor;
-import io.sirix.node.BytesIn;
 import io.sirix.node.Bytes;
+import io.sirix.node.BytesIn;
 import io.sirix.node.BytesOut;
 import io.sirix.node.DeltaVarIntCodec;
 import io.sirix.node.NodeKind;
 import io.sirix.node.SirixDeweyID;
 import io.sirix.node.immutable.xml.ImmutableNamespace;
+import io.sirix.node.interfaces.FlyweightNode;
 import io.sirix.node.interfaces.NameNode;
 import io.sirix.node.interfaces.Node;
-import io.sirix.node.interfaces.ReusableNodeProxy;
 import io.sirix.node.interfaces.immutable.ImmutableXmlNode;
-import io.sirix.node.layout.NodeKindLayout;
-import io.sirix.node.layout.SlotLayoutAccessors;
-import io.sirix.node.layout.StructuralField;
+import io.sirix.page.KeyValueLeafPage;
+import io.sirix.page.NodeFieldLayout;
 import io.sirix.settings.Fixed;
-
-import java.lang.foreign.MemorySegment;
 import io.sirix.utils.NamePageHash;
 import net.openhft.hashing.LongHashFunction;
 import org.checkerframework.checker.index.qual.NonNegative;
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
+import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
+
 /**
  * Node representing an XML namespace, using primitive fields.
  *
+ * 
Supports LeanStore-style flyweight binding: when bound to a slotted page MemorySegment,
+ * getters/setters read/write directly to page memory via the per-record offset table.
+ * When unbound, they operate on Java primitive fields (normal mode).

+ *
  * @author Johannes Lichtenberger
  */
-public final class NamespaceNode implements NameNode, ImmutableXmlNode, Node, ReusableNodeProxy {
+public final class NamespaceNode implements NameNode, ImmutableXmlNode, Node, FlyweightNode {
 
   // === PRIMITIVE FIELDS ===
   private long nodeKey;
@@ -75,23 +79,51 @@ public final class NamespaceNode implements NameNode, ImmutableXmlNode, Node, Re
   private int lastModifiedRevision;
   private long hash;
 
-  // === FIXED-SLOT LAZY SUPPORT ===
-  private Object lazySource;
-  private long lazyBaseOffset;
-  private NodeKindLayout fixedSlotLayout;
-  private boolean lazyFieldsParsed = true;
-
   // === NON-SERIALIZED FIELDS ===
   private LongHashFunction hashFunction;
   private SirixDeweyID sirixDeweyID;
   private byte[] deweyIDBytes;
   private QNm qNm;
 
+  // ==================== FLYWEIGHT BINDING (LeanStore page-direct access) ====================
+
+  /** Page MemorySegment when bound (null = primitive mode). */
+  private MemorySegment page;
+
+  /** Absolute byte offset of this record in the page (after HEAP_START + heapOffset). */
+  private long recordBase;
+
+  /** Absolute byte offset where the data region starts (recordBase + 1 + FIELD_COUNT). */
+  private long dataRegionStart;
+
+  /** Slot index in the page directory (for re-serialization). */
+  private int slotIndex;
+  private boolean writeSingleton;
+  private KeyValueLeafPage ownerPage;
+  private final int[] heapOffsets;
+
+  private static final int FIELD_COUNT = NodeFieldLayout.NAMESPACE_FIELD_COUNT;
+
+  /**
+   * Constructor for flyweight binding.
+   * All fields except nodeKey and hashFunction will be read from page memory after bind().
+   *
+   * @param nodeKey the node key
+   * @param hashFunction the hash function from resource config
+   */
+  public NamespaceNode(final long nodeKey, final LongHashFunction hashFunction) {
+    this.nodeKey = nodeKey;
+    this.hashFunction = hashFunction;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
+
   /**
    * Primary constructor with all primitive fields.
    */
-  public NamespaceNode(long nodeKey, long parentKey, int previousRevision, int lastModifiedRevision, long pathNodeKey,
-      int prefixKey, int localNameKey, int uriKey, long hash, LongHashFunction hashFunction, byte[] deweyID, QNm qNm) {
+  public NamespaceNode(final long nodeKey, final long parentKey, final int previousRevision,
+      final int lastModifiedRevision, final long pathNodeKey, final int prefixKey,
+      final int localNameKey, final int uriKey, final long hash,
+      final LongHashFunction hashFunction, final byte[] deweyID, final QNm qNm) {
     this.nodeKey = nodeKey;
     this.parentKey = parentKey;
     this.previousRevision = previousRevision;
@@ -104,14 +136,16 @@ public NamespaceNode(long nodeKey, long parentKey, int previousRevision, int las
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyID;
     this.qNm = qNm;
+    this.heapOffsets = new int[FIELD_COUNT];
   }
 
   /**
    * Constructor with SirixDeweyID.
    */
-  public NamespaceNode(long nodeKey, long parentKey, int previousRevision, int lastModifiedRevision, long pathNodeKey,
-      int prefixKey, int localNameKey, int uriKey, long hash, LongHashFunction hashFunction, SirixDeweyID deweyID,
-      QNm qNm) {
+  public NamespaceNode(final long nodeKey, final long parentKey, final int previousRevision,
+      final int lastModifiedRevision, final long pathNodeKey, final int prefixKey,
+      final int localNameKey, final int uriKey, final long hash,
+      final LongHashFunction hashFunction, final SirixDeweyID deweyID, final QNm qNm) {
     this.nodeKey = nodeKey;
     this.parentKey = parentKey;
     this.previousRevision = previousRevision;
@@ -124,8 +158,211 @@ public NamespaceNode(long nodeKey, long parentKey, int previousRevision, int las
     this.hashFunction = hashFunction;
     this.sirixDeweyID = deweyID;
     this.qNm = qNm;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
+
+  // ==================== FLYWEIGHT BIND/UNBIND ====================
+
+  /**
+   * Bind this node as a flyweight to a page MemorySegment.
+   * When bound, getters/setters read/write directly to page memory via the offset table.
+   *
+   * @param page       the page MemorySegment
+   * @param recordBase absolute byte offset of this record in the page
+   * @param nodeKey    the node key (for delta decoding)
+   * @param slotIndex  the slot index in the page directory
+   */
+  @Override
+  public void bind(final MemorySegment page, final long recordBase, final long nodeKey,
+      final int slotIndex) {
+    this.page = page;
+    this.recordBase = recordBase;
+    this.nodeKey = nodeKey;
+    this.slotIndex = slotIndex;
+    this.dataRegionStart = recordBase + 1 + FIELD_COUNT;
+  }
+
+  /**
+   * Unbind from page memory and materialize all fields into Java primitives.
+   * After unbind, the node operates in primitive mode.
+   */
+  @Override
+  public void unbind() {
+    if (page == null) {
+      return;
+    }
+    // Materialize all fields from page to Java primitives
+    final long nk = this.nodeKey;
+    this.parentKey = readDeltaField(NodeFieldLayout.NS_PARENT_KEY, nk);
+    this.pathNodeKey = readDeltaField(NodeFieldLayout.NS_PATH_NODE_KEY, nk);
+    this.prefixKey = readSignedField(NodeFieldLayout.NS_PREFIX_KEY);
+    this.localNameKey = readSignedField(NodeFieldLayout.NS_LOCAL_NAME_KEY);
+    this.uriKey = readSignedField(NodeFieldLayout.NS_URI_KEY);
+    this.previousRevision = readSignedField(NodeFieldLayout.NS_PREV_REVISION);
+    this.lastModifiedRevision = readSignedField(NodeFieldLayout.NS_LAST_MOD_REVISION);
+    this.hash = readLongField(NodeFieldLayout.NS_HASH);
+    this.ownerPage = null;
+    this.page = null;
   }
 
+  @Override
+  public void clearBinding() {
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  /** Check if this node is bound to a page MemorySegment. */
+  @Override
+  public boolean isBound() {
+    return page != null;
+  }
+
+  @Override
+  public boolean isBoundTo(final MemorySegment page) {
+    return this.page == page;
+  }
+
+  @Override
+  public int getSlotIndex() {
+    return slotIndex;
+  }
+
+  @Override public boolean isWriteSingleton() { return writeSingleton; }
+  @Override public void setWriteSingleton(final boolean ws) { this.writeSingleton = ws; }
+  @Override public KeyValueLeafPage getOwnerPage() { return ownerPage; }
+  @Override public void setOwnerPage(final KeyValueLeafPage p) { this.ownerPage = p; }
+
+  // ==================== FLYWEIGHT FIELD READ HELPERS ====================
+
+  private long readDeltaField(final int fieldIndex, final long baseKey) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeDeltaFromSegment(page, dataRegionStart + fieldOff, baseKey);
+  }
+
+  private int readSignedField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeSignedFromSegment(page, dataRegionStart + fieldOff);
+  }
+
+  private long readLongField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.readLongFromSegment(page, (int) (dataRegionStart + fieldOff));
+  }
+
+  // ==================== SERIALIZE TO HEAP ====================
+
+  // ==================== DIRECT WRITE ====================
+
+  /**
+   * Encode a NamespaceNode record directly to a MemorySegment from parameter values.
+   * Static -- reads nothing from any instance. Zero field intermediation.
+   *
+   * @param target       the target MemorySegment (reinterpreted slotted page)
+   * @param offset       absolute byte offset to write at
+   * @param heapOffsets  pre-allocated offset array (reused, FIELD_COUNT elements)
+   * @param nodeKey      the node key (delta base for structural keys)
+   * @param parentKey    the parent node key
+   * @param pathNodeKey  the path node key
+   * @param prefixKey    the prefix key
+   * @param localNameKey the local name key
+   * @param uriKey       the URI key
+   * @param prevRev      the previous revision number
+   * @param lastModRev   the last modified revision number
+   * @param hash         the hash value
+   * @return the total number of bytes written
+   */
+  public static int writeNewRecord(final MemorySegment target, final long offset,
+      final int[] heapOffsets, final long nodeKey,
+      final long parentKey, final long pathNodeKey,
+      final int prefixKey, final int localNameKey, final int uriKey,
+      final int prevRev, final int lastModRev, final long hash) {
+    long pos = offset;
+
+    // Write nodeKind byte
+    target.set(ValueLayout.JAVA_BYTE, pos, NodeKind.NAMESPACE.getId());
+    pos++;
+
+    // Reserve space for offset table
+    final long offsetTableStart = pos;
+    pos += FIELD_COUNT;
+
+    // Data region start
+    final long dataStart = pos;
+
+    // Field 0: parentKey (delta-varint)
+    heapOffsets[NodeFieldLayout.NS_PARENT_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, parentKey, nodeKey);
+
+    // Field 1: pathNodeKey (delta-varint)
+    heapOffsets[NodeFieldLayout.NS_PATH_NODE_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, pathNodeKey, nodeKey);
+
+    // Field 2: prefixKey (signed varint)
+    heapOffsets[NodeFieldLayout.NS_PREFIX_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, prefixKey);
+
+    // Field 3: localNameKey (signed varint)
+    heapOffsets[NodeFieldLayout.NS_LOCAL_NAME_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, localNameKey);
+
+    // Field 4: uriKey (signed varint)
+    heapOffsets[NodeFieldLayout.NS_URI_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, uriKey);
+
+    // Field 5: previousRevision (signed varint)
+    heapOffsets[NodeFieldLayout.NS_PREV_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, prevRev);
+
+    // Field 6: lastModifiedRevision (signed varint)
+    heapOffsets[NodeFieldLayout.NS_LAST_MOD_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, lastModRev);
+
+    // Field 7: hash (fixed 8 bytes)
+    heapOffsets[NodeFieldLayout.NS_HASH] = (int) (pos - dataStart);
+    DeltaVarIntCodec.writeLongToSegment(target, pos, hash);
+    pos += Long.BYTES;
+
+    // Write offset table
+    for (int i = 0; i < FIELD_COUNT; i++) {
+      target.set(ValueLayout.JAVA_BYTE, offsetTableStart + i, (byte) heapOffsets[i]);
+    }
+
+    return (int) (pos - offset);
+  }
+
+  /**
+   * Serialize this node from Java fields. Delegates to static writeNewRecord.
+   */
+  @Override
+  public int serializeToHeap(final MemorySegment target, final long offset) {
+    return writeNewRecord(target, offset, heapOffsets, nodeKey,
+        parentKey, pathNodeKey, prefixKey, localNameKey, uriKey,
+        previousRevision, lastModifiedRevision, hash);
+  }
+
+  /**
+   * Get the pre-allocated heap offsets array for use with static writeNewRecord.
+   */
+  public int[] getHeapOffsets() {
+    return heapOffsets;
+  }
+
+  /**
+   * Set DeweyID fields directly after creation, bypassing write-through.
+   * The DeweyID is already in the page trailer -- this just sets the Java cache fields.
+   */
+  public void setDeweyIDAfterCreation(final SirixDeweyID id, final byte[] bytes) {
+    this.sirixDeweyID = id;
+    this.deweyIDBytes = bytes;
+  }
+
+  @Override
+  public int estimateSerializedSize() {
+    return 64;
+  }
+
+  // ==================== NODE IDENTITY ====================
+
   @Override
   public NodeKind getKind() {
     return NodeKind.NAMESPACE;
@@ -137,94 +374,248 @@ public long getNodeKey() {
   }
 
   @Override
-  public void setNodeKey(long nodeKey) {
+  public void setNodeKey(final long nodeKey) {
     this.nodeKey = nodeKey;
   }
 
+  // ==================== DUAL-MODE GETTERS/SETTERS ====================
+
   @Override
   public long getParentKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.NS_PARENT_KEY, nodeKey);
+    }
     return parentKey;
   }
 
-  public void setParentKey(long parentKey) {
+  public void setParentKey(final long parentKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.NS_PARENT_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(parentKey, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, parentKey, nodeKey);
+        return;
+      }
+      resizeParentKey(parentKey);
+      return;
+    }
     this.parentKey = parentKey;
   }
 
+  private void resizeParentKey(final long parentKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.NS_PARENT_KEY, NodeFieldLayout.NAMESPACE_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, parentKey, nodeKey));
+  }
+
   @Override
   public boolean hasParent() {
-    return parentKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getParentKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public long getPathNodeKey() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.NS_PATH_NODE_KEY, nodeKey);
+    }
     return pathNodeKey;
   }
 
   @Override
-  public void setPathNodeKey(@NonNegative long pathNodeKey) {
+  public void setPathNodeKey(@NonNegative final long pathNodeKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.NS_PATH_NODE_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(pathNodeKey, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, pathNodeKey, nodeKey);
+        return;
+      }
+      resizePathNodeKey(pathNodeKey);
+      return;
+    }
     this.pathNodeKey = pathNodeKey;
   }
 
+  private void resizePathNodeKey(final long pathNodeKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.NS_PATH_NODE_KEY, NodeFieldLayout.NAMESPACE_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, pathNodeKey, nodeKey));
+  }
+
   @Override
   public int getPrefixKey() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.NS_PREFIX_KEY);
+    }
     return prefixKey;
   }
 
   @Override
-  public void setPrefixKey(int prefixKey) {
+  public void setPrefixKey(final int prefixKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.NS_PREFIX_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(prefixKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, prefixKey);
+        return;
+      }
+      resizePrefixKey(prefixKey);
+      return;
+    }
     this.prefixKey = prefixKey;
   }
 
+  private void resizePrefixKey(final int prefixKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.NS_PREFIX_KEY, NodeFieldLayout.NAMESPACE_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, prefixKey));
+  }
+
   @Override
   public int getLocalNameKey() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.NS_LOCAL_NAME_KEY);
+    }
     return localNameKey;
   }
 
   @Override
-  public void setLocalNameKey(int localNameKey) {
+  public void setLocalNameKey(final int localNameKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.NS_LOCAL_NAME_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(localNameKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, localNameKey);
+        return;
+      }
+      resizeLocalNameKey(localNameKey);
+      return;
+    }
     this.localNameKey = localNameKey;
   }
 
+  private void resizeLocalNameKey(final int localNameKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.NS_LOCAL_NAME_KEY, NodeFieldLayout.NAMESPACE_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, localNameKey));
+  }
+
   @Override
   public int getURIKey() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.NS_URI_KEY);
+    }
     return uriKey;
   }
 
   @Override
-  public void setURIKey(int uriKey) {
+  public void setURIKey(final int uriKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.NS_URI_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(uriKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, uriKey);
+        return;
+      }
+      resizeURIKey(uriKey);
+      return;
+    }
     this.uriKey = uriKey;
   }
 
+  private void resizeURIKey(final int uriKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.NS_URI_KEY, NodeFieldLayout.NAMESPACE_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, uriKey));
+  }
+
   @Override
   public int getPreviousRevisionNumber() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.NS_PREV_REVISION);
+    }
     return previousRevision;
   }
 
   @Override
-  public void setPreviousRevision(int revision) {
+  public void setPreviousRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.NS_PREV_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizePreviousRevision(revision);
+      return;
+    }
     this.previousRevision = revision;
   }
 
+  private void resizePreviousRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.NS_PREV_REVISION, NodeFieldLayout.NAMESPACE_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+  }
+
   @Override
   public int getLastModifiedRevisionNumber() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.NS_LAST_MOD_REVISION);
+    }
     return lastModifiedRevision;
   }
 
   @Override
-  public void setLastModifiedRevision(int revision) {
+  public void setLastModifiedRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.NS_LAST_MOD_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizeLastModifiedRevision(revision);
+      return;
+    }
     this.lastModifiedRevision = revision;
   }
 
+  private void resizeLastModifiedRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.NS_LAST_MOD_REVISION, NodeFieldLayout.NAMESPACE_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+  }
+
   @Override
   public long getHash() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
+    if (page != null) {
+      // Bound: read hash from MemorySegment. If non-zero (set by rollingAdd/rollingUpdate),
+      // return it as-is to preserve rolling hash arithmetic. If zero (never set), compute.
+      final long storedHash = readLongField(NodeFieldLayout.NS_HASH);
+      if (storedHash != 0L) {
+        return storedHash;
+      }
+      if (hashFunction != null) {
+        return computeHash(Bytes.threadLocalHashBuffer());
+      }
+      return 0L;
+    }
+    // Unbound (in-memory): return stored hash if set by rollingAdd, else compute
     if (hash == 0L && hashFunction != null) {
       hash = computeHash(Bytes.threadLocalHashBuffer());
     }
@@ -232,21 +623,30 @@ public long getHash() {
   }
 
   @Override
-  public void setHash(long hash) {
+  public void setHash(final long hash) {
+    if (page != null) {
+      // Hash is ALWAYS in-place (fixed 8 bytes)
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.NS_HASH) & 0xFF;
+      DeltaVarIntCodec.writeLongToSegment(page, dataRegionStart + fieldOff, hash);
+      return;
+    }
     this.hash = hash;
   }
 
+  // ==================== OTHER GETTERS/SETTERS ====================
+
   @Override
   public QNm getName() {
     return qNm;
   }
 
-  public void setName(QNm name) {
+  public void setName(final QNm name) {
     this.qNm = name;
   }
 
   @Override
-  public boolean isSameItem(@Nullable Node other) {
+  public boolean isSameItem(@Nullable final Node other) {
     return other != null && other.getNodeKey() == nodeKey;
   }
 
@@ -256,15 +656,25 @@ public int getTypeKey() {
   }
 
   @Override
-  public void setTypeKey(int typeKey) {}
+  public void setTypeKey(final int typeKey) {}
 
   @Override
-  public void setDeweyID(SirixDeweyID id) {
+  public void setDeweyID(final SirixDeweyID id) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.sirixDeweyID = id;
+      this.deweyIDBytes = null;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
     this.sirixDeweyID = id;
     this.deweyIDBytes = null;
   }
 
-  public void setDeweyIDBytes(byte[] deweyIDBytes) {
+  public void setDeweyIDBytes(final byte[] deweyIDBytes) {
     this.deweyIDBytes = deweyIDBytes;
     this.sirixDeweyID = null;
   }
@@ -289,11 +699,15 @@ public LongHashFunction getHashFunction() {
     return hashFunction;
   }
 
+  // ==================== DESERIALIZATION ====================
+
   /**
    * Populate this node from a BytesIn source for singleton reuse.
    */
-  public void readFrom(BytesIn source, long nodeKey, byte[] deweyId, LongHashFunction hashFunction,
-      ResourceConfiguration config) {
+  public void readFrom(final BytesIn source, final long nodeKey, final byte[] deweyId,
+      final LongHashFunction hashFunction, final ResourceConfiguration config) {
+    // Unbind flyweight — ensures getters use Java fields, not stale page reference
+    this.page = null;
     this.nodeKey = nodeKey;
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyId;
@@ -312,55 +726,46 @@ public void readFrom(BytesIn source, long nodeKey, byte[] deweyId, LongHashFu
   }
 
   @Override
-  public long computeHash(BytesOut bytes) {
+  public long computeHash(final BytesOut bytes) {
     if (hashFunction == null)
       return 0L;
     bytes.clear();
-    bytes.writeLong(nodeKey).writeLong(parentKey).writeByte(getKind().getId());
-    bytes.writeInt(prefixKey).writeInt(localNameKey).writeInt(uriKey);
+    bytes.writeLong(getNodeKey()).writeLong(getParentKey()).writeByte(getKind().getId());
+    bytes.writeInt(getPrefixKey()).writeInt(getLocalNameKey()).writeInt(getURIKey());
     return bytes.hashDirect(hashFunction);
   }
 
-  public void bindFixedSlotLazy(final MemorySegment slotData, final long baseOffset, final NodeKindLayout layout) {
-    this.lazyBaseOffset = baseOffset;
-    this.lazySource = slotData;
-    this.fixedSlotLayout = layout;
-    this.lazyFieldsParsed = false;
-  }
-
-  private void parseLazyFields() {
-    if (lazyFieldsParsed) {
-      return;
-    }
+  // ==================== SNAPSHOT ====================
 
-    if (fixedSlotLayout != null) {
-      final MemorySegment sd = (MemorySegment) lazySource;
-      final NodeKindLayout ly = fixedSlotLayout;
-      final long off = this.lazyBaseOffset;
-      this.previousRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.PREVIOUS_REVISION);
-      this.lastModifiedRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.LAST_MODIFIED_REVISION);
-      this.hash = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.HASH);
-      this.pathNodeKey = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.PATH_NODE_KEY);
-      this.fixedSlotLayout = null;
-      this.lazyFieldsParsed = true;
-      return;
+  /**
+   * Create a deep copy snapshot of this node.
+   * When bound, reads all fields from page memory. When unbound, uses Java fields.
+   */
+  public NamespaceNode toSnapshot() {
+    if (page != null) {
+      // Bound mode: read all fields from page
+      return new NamespaceNode(nodeKey,
+          readDeltaField(NodeFieldLayout.NS_PARENT_KEY, nodeKey),
+          readSignedField(NodeFieldLayout.NS_PREV_REVISION),
+          readSignedField(NodeFieldLayout.NS_LAST_MOD_REVISION),
+          readDeltaField(NodeFieldLayout.NS_PATH_NODE_KEY, nodeKey),
+          readSignedField(NodeFieldLayout.NS_PREFIX_KEY),
+          readSignedField(NodeFieldLayout.NS_LOCAL_NAME_KEY),
+          readSignedField(NodeFieldLayout.NS_URI_KEY),
+          readLongField(NodeFieldLayout.NS_HASH),
+          hashFunction,
+          getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null,
+          qNm);
     }
-
-    this.lazyFieldsParsed = true;
+    return new NamespaceNode(nodeKey, parentKey, previousRevision, lastModifiedRevision,
+        pathNodeKey, prefixKey, localNameKey, uriKey, hash, hashFunction,
+        getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null, qNm);
   }
 
-  public NamespaceNode toSnapshot() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
-    return new NamespaceNode(nodeKey, parentKey, previousRevision, lastModifiedRevision, pathNodeKey, prefixKey,
-        localNameKey, uriKey, hash, hashFunction, deweyIDBytes != null
-            ? deweyIDBytes.clone()
-            : null,
-        qNm);
-  }
+  // ==================== VISITOR / OBJECT METHODS ====================
 
   @Override
-  public VisitResult acceptVisitor(XmlNodeVisitor visitor) {
+  public VisitResult acceptVisitor(final XmlNodeVisitor visitor) {
     return visitor.visit(ImmutableNamespace.of(this));
   }
 
@@ -370,7 +775,7 @@ public int hashCode() {
   }
 
   @Override
-  public boolean equals(Object obj) {
+  public boolean equals(final Object obj) {
     if (!(obj instanceof NamespaceNode other))
       return false;
     return nodeKey == other.nodeKey && parentKey == other.parentKey && prefixKey == other.prefixKey
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/xml/PINode.java b/bundles/sirix-core/src/main/java/io/sirix/node/xml/PINode.java
index 19a6871cd..c4db95167 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/xml/PINode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/xml/PINode.java
@@ -44,15 +44,14 @@
 import io.sirix.node.NodeKind;
 import io.sirix.node.SirixDeweyID;
 import io.sirix.node.immutable.xml.ImmutablePI;
+import io.sirix.node.interfaces.FlyweightNode;
 import io.sirix.node.interfaces.NameNode;
 import io.sirix.node.interfaces.Node;
-import io.sirix.node.interfaces.ReusableNodeProxy;
 import io.sirix.node.interfaces.StructNode;
 import io.sirix.node.interfaces.ValueNode;
 import io.sirix.node.interfaces.immutable.ImmutableXmlNode;
-import io.sirix.node.layout.NodeKindLayout;
-import io.sirix.node.layout.SlotLayoutAccessors;
-import io.sirix.node.layout.StructuralField;
+import io.sirix.page.KeyValueLeafPage;
+import io.sirix.page.NodeFieldLayout;
 import io.sirix.settings.Constants;
 import io.sirix.settings.Fixed;
 import io.sirix.utils.Compression;
@@ -63,13 +62,18 @@
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
 
 /**
  * Processing Instruction node using primitive fields.
  *
+ * 
Supports LeanStore-style flyweight binding for zero-copy reads from a slotted page
+ * MemorySegment. When bound, all getters/setters operate directly on page memory via
+ * the per-record offset table. When unbound, they operate on Java primitive fields.

+ *
  * @author Johannes Lichtenberger
  */
-public final class PINode implements StructNode, NameNode, ValueNode, ImmutableXmlNode, ReusableNodeProxy {
+public final class PINode implements StructNode, NameNode, ValueNode, ImmutableXmlNode, FlyweightNode {
 
   // === IMMEDIATE STRUCTURAL FIELDS ===
   private long nodeKey;
@@ -101,18 +105,50 @@ public final class PINode implements StructNode, NameNode, ValueNode, ImmutableX
   private boolean lazyValueCompressed;
   private boolean valueParsed = true;
 
-  // === FIXED-SLOT LAZY SUPPORT ===
-  private Object lazySource;
-  private long lazyBaseOffset;
-  private NodeKindLayout fixedSlotLayout;
-  private boolean lazyFieldsParsed = true;
-
   // === NON-SERIALIZED FIELDS ===
   private LongHashFunction hashFunction;
   private SirixDeweyID sirixDeweyID;
   private byte[] deweyIDBytes;
   private QNm qNm;
 
+  // ==================== FLYWEIGHT BINDING (LeanStore page-direct access) ====================
+
+  /** Page MemorySegment when bound (null = primitive mode). */
+  private MemorySegment page;
+
+  /** Absolute byte offset of this record in the page (after HEAP_START + heapOffset). */
+  private long recordBase;
+
+  /** Absolute byte offset where the data region starts (recordBase + 1 + FIELD_COUNT). */
+  private long dataRegionStart;
+
+  /** Slot index in the page directory (for re-serialization). */
+  private int slotIndex;
+
+  /** True if this node is a factory-managed write singleton (must not be stored in records[]). */
+  private boolean writeSingleton;
+
+  /** Owning page for resize-in-place on varint width changes. */
+  private KeyValueLeafPage ownerPage;
+
+  /** Pre-allocated offset array reused across serializations (zero-alloc hot path). */
+  private final int[] heapOffsets;
+
+  private static final int FIELD_COUNT = NodeFieldLayout.PI_FIELD_COUNT;
+
+  /**
+   * Constructor for flyweight binding.
+   * All fields except nodeKey and hashFunction will be read from page memory after bind().
+   *
+   * @param nodeKey the node key
+   * @param hashFunction the hash function from resource config
+   */
+  public PINode(long nodeKey, LongHashFunction hashFunction) {
+    this.nodeKey = nodeKey;
+    this.hashFunction = hashFunction;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
+
   /**
    * Primary constructor with all primitive fields.
    */
@@ -140,6 +176,7 @@ public PINode(long nodeKey, long parentKey, int previousRevision, int lastModifi
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyID;
     this.qNm = qNm;
+    this.heapOffsets = new int[FIELD_COUNT];
   }
 
   /**
@@ -169,6 +206,288 @@ public PINode(long nodeKey, long parentKey, int previousRevision, int lastModifi
     this.hashFunction = hashFunction;
     this.sirixDeweyID = deweyID;
     this.qNm = qNm;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
+
+  // ==================== FLYWEIGHT BIND/UNBIND ====================
+
+  /**
+   * Bind this node as a flyweight to a page MemorySegment.
+   * When bound, getters/setters read/write directly to page memory via the offset table.
+   *
+   * @param page       the page MemorySegment
+   * @param recordBase absolute byte offset of this record in the page
+   * @param nodeKey    the node key (for delta decoding)
+   * @param slotIndex  the slot index in the page directory
+   */
+  public void bind(final MemorySegment page, final long recordBase, final long nodeKey,
+      final int slotIndex) {
+    this.page = page;
+    this.recordBase = recordBase;
+    this.nodeKey = nodeKey;
+    this.slotIndex = slotIndex;
+    this.dataRegionStart = recordBase + 1 + FIELD_COUNT;
+    this.valueParsed = false; // Payload still needs lazy parsing from page
+    this.lazyValueSource = null;
+    this.hash = 0;
+  }
+
+  /**
+   * Unbind from page memory and materialize all fields into Java primitives.
+   * After unbind, the node operates in primitive mode.
+   */
+  public void unbind() {
+    if (page == null) {
+      return;
+    }
+    // Materialize all fields from page to Java primitives
+    final long nk = this.nodeKey;
+    this.parentKey = readDeltaField(NodeFieldLayout.PI_PARENT_KEY, nk);
+    this.rightSiblingKey = readDeltaField(NodeFieldLayout.PI_RIGHT_SIB_KEY, nk);
+    this.leftSiblingKey = readDeltaField(NodeFieldLayout.PI_LEFT_SIB_KEY, nk);
+    this.firstChildKey = readDeltaField(NodeFieldLayout.PI_FIRST_CHILD_KEY, nk);
+    this.lastChildKey = readDeltaField(NodeFieldLayout.PI_LAST_CHILD_KEY, nk);
+    this.pathNodeKey = readDeltaField(NodeFieldLayout.PI_PATH_NODE_KEY, nk);
+    this.prefixKey = readSignedField(NodeFieldLayout.PI_PREFIX_KEY);
+    this.localNameKey = readSignedField(NodeFieldLayout.PI_LOCAL_NAME_KEY);
+    this.uriKey = readSignedField(NodeFieldLayout.PI_URI_KEY);
+    this.previousRevision = readSignedField(NodeFieldLayout.PI_PREV_REVISION);
+    this.lastModifiedRevision = readSignedField(NodeFieldLayout.PI_LAST_MOD_REVISION);
+    this.childCount = readSignedLongField(NodeFieldLayout.PI_CHILD_COUNT);
+    this.descendantCount = readSignedLongField(NodeFieldLayout.PI_DESCENDANT_COUNT);
+    // Payload needs to be read from page before unbinding
+    if (!valueParsed) {
+      readPayloadFromPage();
+    }
+    this.ownerPage = null;
+    this.page = null;
+  }
+
+  @Override
+  public void clearBinding() {
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  /** Check if this node is bound to a page MemorySegment. */
+  public boolean isBound() {
+    return page != null;
+  }
+
+  @Override
+  public boolean isBoundTo(final MemorySegment page) {
+    return this.page == page;
+  }
+
+  @Override
+  public int getSlotIndex() {
+    return slotIndex;
+  }
+
+  @Override
+  public boolean isWriteSingleton() { return writeSingleton; }
+
+  @Override
+  public void setWriteSingleton(final boolean writeSingleton) { this.writeSingleton = writeSingleton; }
+
+  @Override
+  public KeyValueLeafPage getOwnerPage() { return ownerPage; }
+
+  @Override
+  public void setOwnerPage(final KeyValueLeafPage ownerPage) { this.ownerPage = ownerPage; }
+
+  @Override
+  public int estimateSerializedSize() {
+    final int payloadLen = value != null ? value.length : 0;
+    return 119 + payloadLen;
+  }
+
+  // ==================== FLYWEIGHT FIELD READ HELPERS ====================
+
+  private long readDeltaField(final int fieldIndex, final long baseKey) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeDeltaFromSegment(page, dataRegionStart + fieldOff, baseKey);
+  }
+
+  private int readSignedField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeSignedFromSegment(page, dataRegionStart + fieldOff);
+  }
+
+  private long readSignedLongField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeSignedLongFromSegment(page, dataRegionStart + fieldOff);
+  }
+
+  /**
+   * Read the payload (value bytes) directly from page memory when bound.
+   */
+  private void readPayloadFromPage() {
+    final int payloadFieldOff = page.get(ValueLayout.JAVA_BYTE,
+        recordBase + 1 + NodeFieldLayout.PI_PAYLOAD) & 0xFF;
+    final long payloadStart = dataRegionStart + payloadFieldOff;
+
+    // Read isCompressed flag (1 byte)
+    this.isCompressed = page.get(ValueLayout.JAVA_BYTE, payloadStart) == 1;
+
+    // Read value length (varint)
+    final long lenOffset = payloadStart + 1;
+    final int length = DeltaVarIntCodec.decodeSignedFromSegment(page, lenOffset);
+    final int lenBytes = DeltaVarIntCodec.readSignedVarintWidth(page, lenOffset);
+
+    // Read value bytes
+    final long dataOffset = lenOffset + lenBytes;
+    this.value = new byte[length];
+    MemorySegment.copy(page, ValueLayout.JAVA_BYTE, dataOffset, this.value, 0, length);
+    this.valueParsed = true;
+  }
+
+  // ==================== SERIALIZE TO HEAP ====================
+
+  /**
+   * Encode a PINode record directly to a MemorySegment from parameter values.
+   * Static -- reads nothing from any instance. Zero field intermediation.
+   *
+   * @param target          the target MemorySegment (reinterpreted slotted page)
+   * @param offset          absolute byte offset to write at
+   * @param heapOffsets     pre-allocated offset array (reused, FIELD_COUNT elements)
+   * @param nodeKey         the node key (delta base for structural keys)
+   * @param parentKey       the parent node key
+   * @param rightSibKey     the right sibling key
+   * @param leftSibKey      the left sibling key
+   * @param firstChildKey   the first child key
+   * @param lastChildKey    the last child key
+   * @param pathNodeKey     the path node key
+   * @param prefixKey       the prefix key
+   * @param localNameKey    the local name key
+   * @param uriKey          the URI key
+   * @param prevRev         the previous revision number
+   * @param lastModRev      the last modified revision number
+   * @param childCount      the child count
+   * @param descendantCount the descendant count
+   * @param rawValue        the raw value bytes (possibly compressed)
+   * @param isCompressed    whether the value is compressed
+   * @return the total number of bytes written
+   */
+  public static int writeNewRecord(final MemorySegment target, final long offset,
+      final int[] heapOffsets, final long nodeKey,
+      final long parentKey, final long rightSibKey, final long leftSibKey,
+      final long firstChildKey, final long lastChildKey,
+      final long pathNodeKey, final int prefixKey, final int localNameKey, final int uriKey,
+      final int prevRev, final int lastModRev,
+      final long childCount, final long descendantCount,
+      final byte[] rawValue, final boolean isCompressed) {
+    long pos = offset;
+
+    // Write nodeKind byte
+    target.set(ValueLayout.JAVA_BYTE, pos, NodeKind.PROCESSING_INSTRUCTION.getId());
+    pos++;
+
+    // Reserve space for offset table
+    final long offsetTableStart = pos;
+    pos += FIELD_COUNT;
+
+    // Data region start
+    final long dataStart = pos;
+
+    // Field 0: parentKey (delta-varint)
+    heapOffsets[NodeFieldLayout.PI_PARENT_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, parentKey, nodeKey);
+
+    // Field 1: rightSiblingKey (delta-varint)
+    heapOffsets[NodeFieldLayout.PI_RIGHT_SIB_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, rightSibKey, nodeKey);
+
+    // Field 2: leftSiblingKey (delta-varint)
+    heapOffsets[NodeFieldLayout.PI_LEFT_SIB_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, leftSibKey, nodeKey);
+
+    // Field 3: firstChildKey (delta-varint)
+    heapOffsets[NodeFieldLayout.PI_FIRST_CHILD_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, firstChildKey, nodeKey);
+
+    // Field 4: lastChildKey (delta-varint)
+    heapOffsets[NodeFieldLayout.PI_LAST_CHILD_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, lastChildKey, nodeKey);
+
+    // Field 5: pathNodeKey (delta-varint)
+    heapOffsets[NodeFieldLayout.PI_PATH_NODE_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, pathNodeKey, nodeKey);
+
+    // Field 6: prefixKey (signed varint)
+    heapOffsets[NodeFieldLayout.PI_PREFIX_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, prefixKey);
+
+    // Field 7: localNameKey (signed varint)
+    heapOffsets[NodeFieldLayout.PI_LOCAL_NAME_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, localNameKey);
+
+    // Field 8: uriKey (signed varint)
+    heapOffsets[NodeFieldLayout.PI_URI_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, uriKey);
+
+    // Field 9: previousRevision (signed varint)
+    heapOffsets[NodeFieldLayout.PI_PREV_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, prevRev);
+
+    // Field 10: lastModifiedRevision (signed varint)
+    heapOffsets[NodeFieldLayout.PI_LAST_MOD_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, lastModRev);
+
+    // Field 11: childCount (signed long varint)
+    heapOffsets[NodeFieldLayout.PI_CHILD_COUNT] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedLongToSegment(target, pos, childCount);
+
+    // Field 12: descendantCount (signed long varint)
+    heapOffsets[NodeFieldLayout.PI_DESCENDANT_COUNT] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedLongToSegment(target, pos, descendantCount);
+
+    // Field 13: payload [isCompressed:1][valueLength:varint][value:bytes]
+    heapOffsets[NodeFieldLayout.PI_PAYLOAD] = (int) (pos - dataStart);
+    target.set(ValueLayout.JAVA_BYTE, pos, isCompressed ? (byte) 1 : (byte) 0);
+    pos++;
+    final byte[] val = rawValue != null ? rawValue : new byte[0];
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, val.length);
+    if (val.length > 0) {
+      MemorySegment.copy(val, 0, target, ValueLayout.JAVA_BYTE, pos, val.length);
+      pos += val.length;
+    }
+
+    // Write offset table
+    for (int i = 0; i < FIELD_COUNT; i++) {
+      target.set(ValueLayout.JAVA_BYTE, offsetTableStart + i, (byte) heapOffsets[i]);
+    }
+
+    return (int) (pos - offset);
+  }
+
+  /**
+   * Serialize this node from Java fields. Delegates to static writeNewRecord.
+   */
+  public int serializeToHeap(final MemorySegment target, final long offset) {
+    if (!valueParsed) parseLazyValue();
+    return writeNewRecord(target, offset, heapOffsets, nodeKey,
+        parentKey, rightSiblingKey, leftSiblingKey,
+        firstChildKey, lastChildKey, pathNodeKey,
+        prefixKey, localNameKey, uriKey,
+        previousRevision, lastModifiedRevision,
+        childCount, descendantCount, value, isCompressed);
+  }
+
+  /**
+   * Get the pre-allocated heap offsets array for use with static writeNewRecord.
+   */
+  public int[] getHeapOffsets() {
+    return heapOffsets;
+  }
+
+  /**
+   * Set DeweyID fields directly after creation, bypassing write-through.
+   * The DeweyID is already in the page trailer -- this just sets the Java cache fields.
+   */
+  public void setDeweyIDAfterCreation(final SirixDeweyID id, final byte[] bytes) {
+    this.sirixDeweyID = id;
+    this.deweyIDBytes = bytes;
   }
 
   @Override
@@ -188,202 +507,453 @@ public void setNodeKey(long nodeKey) {
 
   @Override
   public long getParentKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.PI_PARENT_KEY, nodeKey);
+    }
     return parentKey;
   }
 
-  public void setParentKey(long parentKey) {
+  public void setParentKey(final long parentKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.PI_PARENT_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(parentKey, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, parentKey, nodeKey);
+        return;
+      }
+      resizeParentKey(parentKey);
+      return;
+    }
     this.parentKey = parentKey;
   }
 
+  private void resizeParentKey(final long parentKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.PI_PARENT_KEY, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, parentKey, nodeKey));
+  }
+
   @Override
   public boolean hasParent() {
-    return parentKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getParentKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public long getRightSiblingKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.PI_RIGHT_SIB_KEY, nodeKey);
+    }
     return rightSiblingKey;
   }
 
-  public void setRightSiblingKey(long key) {
+  public void setRightSiblingKey(final long key) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.PI_RIGHT_SIB_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(key, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, key, nodeKey);
+        return;
+      }
+      resizeRightSiblingKey(key);
+      return;
+    }
     this.rightSiblingKey = key;
   }
 
+  private void resizeRightSiblingKey(final long key) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.PI_RIGHT_SIB_KEY, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, key, nodeKey));
+  }
+
   @Override
   public boolean hasRightSibling() {
-    return rightSiblingKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getRightSiblingKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public long getLeftSiblingKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.PI_LEFT_SIB_KEY, nodeKey);
+    }
     return leftSiblingKey;
   }
 
-  public void setLeftSiblingKey(long key) {
+  public void setLeftSiblingKey(final long key) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.PI_LEFT_SIB_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(key, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, key, nodeKey);
+        return;
+      }
+      resizeLeftSiblingKey(key);
+      return;
+    }
     this.leftSiblingKey = key;
   }
 
+  private void resizeLeftSiblingKey(final long key) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.PI_LEFT_SIB_KEY, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, key, nodeKey));
+  }
+
   @Override
   public boolean hasLeftSibling() {
-    return leftSiblingKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getLeftSiblingKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public long getFirstChildKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.PI_FIRST_CHILD_KEY, nodeKey);
+    }
     return firstChildKey;
   }
 
-  public void setFirstChildKey(long key) {
+  public void setFirstChildKey(final long key) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.PI_FIRST_CHILD_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(key, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, key, nodeKey);
+        return;
+      }
+      resizeFirstChildKey(key);
+      return;
+    }
     this.firstChildKey = key;
   }
 
+  private void resizeFirstChildKey(final long key) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.PI_FIRST_CHILD_KEY, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, key, nodeKey));
+  }
+
   @Override
   public boolean hasFirstChild() {
-    return firstChildKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getFirstChildKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public long getLastChildKey() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.PI_LAST_CHILD_KEY, nodeKey);
+    }
     return lastChildKey;
   }
 
-  public void setLastChildKey(long key) {
+  public void setLastChildKey(final long key) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.PI_LAST_CHILD_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(key, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, key, nodeKey);
+        return;
+      }
+      resizeLastChildKey(key);
+      return;
+    }
     this.lastChildKey = key;
   }
 
+  private void resizeLastChildKey(final long key) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.PI_LAST_CHILD_KEY, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, key, nodeKey));
+  }
+
   @Override
   public boolean hasLastChild() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
-    return lastChildKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getLastChildKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public long getChildCount() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
+    if (page != null) {
+      return readSignedLongField(NodeFieldLayout.PI_CHILD_COUNT);
+    }
     return childCount;
   }
 
-  public void setChildCount(long childCount) {
+  public void setChildCount(final long childCount) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.PI_CHILD_COUNT) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedLongEncodedWidth(childCount);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedLongToSegment(page, absOff, childCount);
+        return;
+      }
+      resizeChildCount(childCount);
+      return;
+    }
     this.childCount = childCount;
   }
 
+  private void resizeChildCount(final long childCount) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.PI_CHILD_COUNT, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedLongToSegment(target, off, childCount));
+  }
+
   @Override
   public void incrementChildCount() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
-    childCount++;
+    setChildCount(getChildCount() + 1);
   }
 
   @Override
   public void decrementChildCount() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
-    childCount--;
+    setChildCount(getChildCount() - 1);
   }
 
   @Override
   public long getDescendantCount() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
+    if (page != null) {
+      return readSignedLongField(NodeFieldLayout.PI_DESCENDANT_COUNT);
+    }
     return descendantCount;
   }
 
   @Override
-  public void setDescendantCount(long descendantCount) {
+  public void setDescendantCount(final long descendantCount) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.PI_DESCENDANT_COUNT) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedLongEncodedWidth(descendantCount);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedLongToSegment(page, absOff, descendantCount);
+        return;
+      }
+      resizeDescendantCount(descendantCount);
+      return;
+    }
     this.descendantCount = descendantCount;
   }
 
+  private void resizeDescendantCount(final long descendantCount) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.PI_DESCENDANT_COUNT, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedLongToSegment(target, off, descendantCount));
+  }
+
   @Override
   public void incrementDescendantCount() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
-    descendantCount++;
+    setDescendantCount(getDescendantCount() + 1);
   }
 
   @Override
   public void decrementDescendantCount() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
-    descendantCount--;
+    setDescendantCount(getDescendantCount() - 1);
   }
 
   @Override
   public long getPathNodeKey() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.PI_PATH_NODE_KEY, nodeKey);
+    }
     return pathNodeKey;
   }
 
   @Override
   public void setPathNodeKey(@NonNegative long pathNodeKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.PI_PATH_NODE_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(pathNodeKey, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, pathNodeKey, nodeKey);
+        return;
+      }
+      resizePathNodeKey(pathNodeKey);
+      return;
+    }
     this.pathNodeKey = pathNodeKey;
   }
 
+  private void resizePathNodeKey(final long pathNodeKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.PI_PATH_NODE_KEY, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, pathNodeKey, nodeKey));
+  }
+
   @Override
   public int getPrefixKey() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.PI_PREFIX_KEY);
+    }
     return prefixKey;
   }
 
   @Override
   public void setPrefixKey(int prefixKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.PI_PREFIX_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(prefixKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, prefixKey);
+        return;
+      }
+      resizePrefixKey(prefixKey);
+      return;
+    }
     this.prefixKey = prefixKey;
   }
 
+  private void resizePrefixKey(final int prefixKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.PI_PREFIX_KEY, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, prefixKey));
+  }
+
   @Override
   public int getLocalNameKey() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.PI_LOCAL_NAME_KEY);
+    }
     return localNameKey;
   }
 
   @Override
   public void setLocalNameKey(int localNameKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.PI_LOCAL_NAME_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(localNameKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, localNameKey);
+        return;
+      }
+      resizeLocalNameKey(localNameKey);
+      return;
+    }
     this.localNameKey = localNameKey;
   }
 
+  private void resizeLocalNameKey(final int localNameKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.PI_LOCAL_NAME_KEY, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, localNameKey));
+  }
+
   @Override
   public int getURIKey() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.PI_URI_KEY);
+    }
     return uriKey;
   }
 
   @Override
   public void setURIKey(int uriKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.PI_URI_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(uriKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, uriKey);
+        return;
+      }
+      resizeURIKey(uriKey);
+      return;
+    }
     this.uriKey = uriKey;
   }
 
+  private void resizeURIKey(final int uriKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.PI_URI_KEY, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, uriKey));
+  }
+
   @Override
   public int getPreviousRevisionNumber() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.PI_PREV_REVISION);
+    }
     return previousRevision;
   }
 
   @Override
   public void setPreviousRevision(int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.PI_PREV_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizePreviousRevision(revision);
+      return;
+    }
     this.previousRevision = revision;
   }
 
+  private void resizePreviousRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.PI_PREV_REVISION, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+  }
+
   @Override
   public int getLastModifiedRevisionNumber() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.PI_LAST_MOD_REVISION);
+    }
     return lastModifiedRevision;
   }
 
   @Override
   public void setLastModifiedRevision(int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.PI_LAST_MOD_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizeLastModifiedRevision(revision);
+      return;
+    }
     this.lastModifiedRevision = revision;
   }
 
+  private void resizeLastModifiedRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.PI_LAST_MOD_REVISION, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+  }
+
   @Override
   public long getHash() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
-    if (hash == 0L && hashFunction != null) {
+    // Return stored hash if set by rollingAdd/rollingUpdate, else compute on demand
+    if (hash != 0L) {
+      return hash;
+    }
+    if (hashFunction != null) {
       hash = computeHash(Bytes.threadLocalHashBuffer());
     }
     return hash;
@@ -396,7 +966,9 @@ public void setHash(long hash) {
 
   @Override
   public byte[] getRawValue() {
-    if (!valueParsed) {
+    if (page != null && !valueParsed) {
+      readPayloadFromPage();
+    } else if (!valueParsed) {
       parseLazyValue();
     }
     if (value != null && isCompressed) {
@@ -408,6 +980,23 @@ public byte[] getRawValue() {
 
   @Override
   public void setRawValue(byte[] value) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.value = value;
+      this.valueParsed = true;
+      this.lazyValueSource = null;
+      this.lazyValueOffset = 0L;
+      this.lazyValueLength = 0;
+      this.lazyValueCompressed = false;
+      this.isCompressed = false;
+      this.hash = 0L;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
+    if (page != null) unbind();
     this.value = value;
     this.valueParsed = true;
     this.lazyValueSource = null;
@@ -431,8 +1020,9 @@ public void setLazyRawValue(Object source, long valueOffset, int valueLength, bo
 
   @Override
   public String getValue() {
-    return value != null
-        ? new String(value, Constants.DEFAULT_ENCODING)
+    final byte[] raw = getRawValue();
+    return raw != null
+        ? new String(raw, Constants.DEFAULT_ENCODING)
         : "";
   }
 
@@ -450,13 +1040,18 @@ public void setName(QNm name) {
    * preserve the original compressed bytes.
    */
   public byte[] getRawValueWithoutDecompression() {
-    if (!valueParsed) {
+    if (page != null && !valueParsed) {
+      readPayloadFromPage();
+    } else if (!valueParsed) {
       parseLazyValue();
     }
     return value;
   }
 
   public boolean isCompressed() {
+    if (page != null && !valueParsed) {
+      readPayloadFromPage();
+    }
     return isCompressed;
   }
 
@@ -479,6 +1074,16 @@ public void setTypeKey(int typeKey) {}
 
   @Override
   public void setDeweyID(SirixDeweyID id) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.sirixDeweyID = id;
+      this.deweyIDBytes = null;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
     this.sirixDeweyID = id;
     this.deweyIDBytes = null;
   }
@@ -513,6 +1118,8 @@ public LongHashFunction getHashFunction() {
    */
   public void readFrom(BytesIn source, long nodeKey, byte[] deweyId, LongHashFunction hashFunction,
       ResourceConfiguration config) {
+    // Unbind flyweight -- ensures getters use Java fields, not stale page reference
+    this.page = null;
     this.nodeKey = nodeKey;
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyId;
@@ -588,16 +1195,8 @@ public long computeHash(BytesOut bytes) {
     if (hashFunction == null)
       return 0L;
     bytes.clear();
-    bytes.writeLong(nodeKey).writeLong(parentKey).writeByte(getKind().getId());
-    bytes.writeLong(childCount)
-         .writeLong(descendantCount)
-         .writeLong(leftSiblingKey)
-         .writeLong(rightSiblingKey)
-         .writeLong(firstChildKey);
-    if (lastChildKey != Fixed.INVALID_KEY_FOR_TYPE_CHECK.getStandardProperty()) {
-      bytes.writeLong(lastChildKey);
-    }
-    bytes.writeInt(prefixKey).writeInt(localNameKey).writeInt(uriKey);
+    bytes.writeLong(getNodeKey()).writeLong(getParentKey()).writeByte(getKind().getId());
+    bytes.writeInt(getPrefixKey()).writeInt(getLocalNameKey()).writeInt(getURIKey());
     final byte[] rawValue = getRawValue();
     if (rawValue != null) {
       bytes.write(rawValue);
@@ -605,51 +1204,59 @@ public long computeHash(BytesOut bytes) {
     return bytes.hashDirect(hashFunction);
   }
 
-  public void bindFixedSlotLazy(final MemorySegment slotData, final long baseOffset, final NodeKindLayout layout) {
-    this.lazyBaseOffset = baseOffset;
-    this.lazySource = slotData;
-    this.fixedSlotLayout = layout;
-    this.lazyFieldsParsed = false;
-  }
-
-  private void parseLazyFields() {
-    if (lazyFieldsParsed) {
-      return;
+  /**
+   * Create a deep copy snapshot of this node.
+   *
+   * @return a new instance with copied values
+   */
+  public PINode toSnapshot() {
+    if (page != null) {
+      final long nk = this.nodeKey;
+      if (!valueParsed) {
+        readPayloadFromPage();
+      }
+      final PINode snapshot = new PINode(
+          nk,
+          readDeltaField(NodeFieldLayout.PI_PARENT_KEY, nk),
+          readSignedField(NodeFieldLayout.PI_PREV_REVISION),
+          readSignedField(NodeFieldLayout.PI_LAST_MOD_REVISION),
+          readDeltaField(NodeFieldLayout.PI_RIGHT_SIB_KEY, nk),
+          readDeltaField(NodeFieldLayout.PI_LEFT_SIB_KEY, nk),
+          readDeltaField(NodeFieldLayout.PI_FIRST_CHILD_KEY, nk),
+          readDeltaField(NodeFieldLayout.PI_LAST_CHILD_KEY, nk),
+          readSignedLongField(NodeFieldLayout.PI_CHILD_COUNT),
+          readSignedLongField(NodeFieldLayout.PI_DESCENDANT_COUNT),
+          hash,
+          readDeltaField(NodeFieldLayout.PI_PATH_NODE_KEY, nk),
+          readSignedField(NodeFieldLayout.PI_PREFIX_KEY),
+          readSignedField(NodeFieldLayout.PI_LOCAL_NAME_KEY),
+          readSignedField(NodeFieldLayout.PI_URI_KEY),
+          value != null ? value.clone() : null,
+          isCompressed,
+          hashFunction,
+          getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null,
+          qNm);
+      if (sirixDeweyID != null) {
+        snapshot.sirixDeweyID = sirixDeweyID;
+      }
+      return snapshot;
     }
-
-    if (fixedSlotLayout != null) {
-      final MemorySegment sd = (MemorySegment) lazySource;
-      final NodeKindLayout ly = fixedSlotLayout;
-      final long off = this.lazyBaseOffset;
-      this.previousRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.PREVIOUS_REVISION);
-      this.lastModifiedRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.LAST_MODIFIED_REVISION);
-      this.lastChildKey = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.LAST_CHILD_KEY);
-      this.childCount = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.CHILD_COUNT);
-      this.descendantCount = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.DESCENDANT_COUNT);
-      this.hash = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.HASH);
-      this.pathNodeKey = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.PATH_NODE_KEY);
-      this.uriKey = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.URI_KEY);
-      this.fixedSlotLayout = null;
-      this.lazyFieldsParsed = true;
-      return;
+    if (!valueParsed) {
+      parseLazyValue();
     }
-
-    this.lazyFieldsParsed = true;
-  }
-
-  public PINode toSnapshot() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
-    final byte[] rawValue = getRawValue();
-    return new PINode(nodeKey, parentKey, previousRevision, lastModifiedRevision, rightSiblingKey, leftSiblingKey,
-        firstChildKey, lastChildKey, childCount, descendantCount, hash, pathNodeKey, prefixKey, localNameKey, uriKey,
-        rawValue != null
-            ? rawValue.clone()
-            : null,
-        isCompressed, hashFunction, deweyIDBytes != null
-            ? deweyIDBytes.clone()
-            : null,
+    final PINode snapshot = new PINode(
+        nodeKey, parentKey, previousRevision, lastModifiedRevision,
+        rightSiblingKey, leftSiblingKey, firstChildKey, lastChildKey,
+        childCount, descendantCount, hash, pathNodeKey,
+        prefixKey, localNameKey, uriKey,
+        value != null ? value.clone() : null,
+        isCompressed, hashFunction,
+        getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null,
         qNm);
+    if (sirixDeweyID != null) {
+      snapshot.sirixDeweyID = sirixDeweyID;
+    }
+    return snapshot;
   }
 
   @Override
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/xml/TextNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/xml/TextNode.java
index 4b550b0aa..1d6847193 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/xml/TextNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/xml/TextNode.java
@@ -42,14 +42,13 @@
 import io.sirix.node.NodeKind;
 import io.sirix.node.SirixDeweyID;
 import io.sirix.node.immutable.xml.ImmutableText;
+import io.sirix.node.interfaces.FlyweightNode;
 import io.sirix.node.interfaces.Node;
-import io.sirix.node.interfaces.ReusableNodeProxy;
 import io.sirix.node.interfaces.StructNode;
 import io.sirix.node.interfaces.ValueNode;
 import io.sirix.node.interfaces.immutable.ImmutableXmlNode;
-import io.sirix.node.layout.NodeKindLayout;
-import io.sirix.node.layout.SlotLayoutAccessors;
-import io.sirix.node.layout.StructuralField;
+import io.sirix.page.KeyValueLeafPage;
+import io.sirix.page.NodeFieldLayout;
 import io.sirix.settings.Constants;
 import io.sirix.settings.Fixed;
 import io.sirix.utils.Compression;
@@ -59,6 +58,7 @@
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
 
 /**
  * Text node implementation using primitive fields.
@@ -70,7 +70,7 @@
  *
  * @author Johannes Lichtenberger
  */
-public final class TextNode implements StructNode, ValueNode, ImmutableXmlNode, ReusableNodeProxy {
+public final class TextNode implements StructNode, ValueNode, ImmutableXmlNode, FlyweightNode {
 
   // === IMMEDIATE STRUCTURAL FIELDS ===
   private long nodeKey;
@@ -97,15 +97,33 @@ public final class TextNode implements StructNode, ValueNode, ImmutableXmlNode,
   private long lazyOffset;
   private boolean metadataParsed;
   private boolean valueParsed;
-  private boolean hasHash;
   private long valueOffset;
   private boolean fixedValueEncoding;
   private int fixedValueLength;
   private boolean fixedValueCompressed;
 
-  // Fixed-slot lazy metadata support
-  private long lazyBaseOffset;
-  private NodeKindLayout fixedSlotLayout;
+  // ==================== FLYWEIGHT BINDING (LeanStore page-direct access) ====================
+  private MemorySegment page;
+  private long recordBase;
+  private long dataRegionStart;
+  private int slotIndex;
+  private boolean writeSingleton;
+  private KeyValueLeafPage ownerPage;
+  private final int[] heapOffsets;
+  private static final int FIELD_COUNT = NodeFieldLayout.TEXT_FIELD_COUNT;
+
+  /**
+   * Constructor for flyweight binding.
+   * All fields except nodeKey and hashFunction will be read from page memory after bind().
+   *
+   * @param nodeKey the node key
+   * @param hashFunction the hash function from resource config
+   */
+  public TextNode(long nodeKey, LongHashFunction hashFunction) {
+    this.nodeKey = nodeKey;
+    this.hashFunction = hashFunction;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
 
   /**
    * Primary constructor with all primitive fields.
@@ -126,6 +144,7 @@ public TextNode(long nodeKey, long parentKey, int previousRevision, int lastModi
     this.deweyIDBytes = deweyID;
     this.metadataParsed = true;
     this.valueParsed = true;
+    this.heapOffsets = new int[FIELD_COUNT];
   }
 
   /**
@@ -147,6 +166,212 @@ public TextNode(long nodeKey, long parentKey, int previousRevision, int lastModi
     this.sirixDeweyID = deweyID;
     this.metadataParsed = true;
     this.valueParsed = true;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
+
+  // ==================== FLYWEIGHT BIND/UNBIND ====================
+
+  @Override
+  public void bind(final MemorySegment page, final long recordBase, final long nodeKey,
+      final int slotIndex) {
+    this.page = page;
+    this.recordBase = recordBase;
+    this.nodeKey = nodeKey;
+    this.slotIndex = slotIndex;
+    this.dataRegionStart = recordBase + 1 + FIELD_COUNT;
+    this.metadataParsed = true;
+    this.valueParsed = false; // Payload still needs lazy parsing from page
+    this.lazySource = null;
+    this.hash = 0;
+  }
+
+  @Override
+  public void unbind() {
+    if (page == null) return;
+    final long nk = this.nodeKey;
+    this.parentKey = readDeltaField(NodeFieldLayout.TEXT_PARENT_KEY, nk);
+    this.rightSiblingKey = readDeltaField(NodeFieldLayout.TEXT_RIGHT_SIB_KEY, nk);
+    this.leftSiblingKey = readDeltaField(NodeFieldLayout.TEXT_LEFT_SIB_KEY, nk);
+    this.previousRevision = readSignedField(NodeFieldLayout.TEXT_PREV_REVISION);
+    this.lastModifiedRevision = readSignedField(NodeFieldLayout.TEXT_LAST_MOD_REVISION);
+    // Hash is not stored on the slotted page; keep current in-memory value
+    // Payload needs to be read from page before unbinding
+    if (!valueParsed) {
+      readPayloadFromPage();
+    }
+    this.ownerPage = null;
+    this.page = null;
+  }
+
+  @Override
+  public void clearBinding() {
+    this.ownerPage = null;
+    this.page = null;
+  }
+
+  @Override
+  public boolean isBound() {
+    return page != null;
+  }
+
+  @Override
+  public boolean isBoundTo(final MemorySegment page) {
+    return this.page == page;
+  }
+
+  @Override
+  public int getSlotIndex() {
+    return slotIndex;
+  }
+
+  @Override public boolean isWriteSingleton() { return writeSingleton; }
+  @Override public void setWriteSingleton(final boolean ws) { this.writeSingleton = ws; }
+  @Override public KeyValueLeafPage getOwnerPage() { return ownerPage; }
+  @Override public void setOwnerPage(final KeyValueLeafPage p) { this.ownerPage = p; }
+
+  @Override
+  public int estimateSerializedSize() {
+    final int payloadLen = value != null ? value.length : 0;
+    return 55 + payloadLen;
+  }
+
+  // ==================== FLYWEIGHT FIELD READ HELPERS ====================
+
+  private long readDeltaField(final int fieldIndex, final long baseKey) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeDeltaFromSegment(page, dataRegionStart + fieldOff, baseKey);
+  }
+
+  private int readSignedField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeSignedFromSegment(page, dataRegionStart + fieldOff);
+  }
+
+  /**
+   * Read the payload (value bytes) directly from page memory when bound.
+   */
+  private void readPayloadFromPage() {
+    final int payloadFieldOff = page.get(ValueLayout.JAVA_BYTE,
+        recordBase + 1 + NodeFieldLayout.TEXT_PAYLOAD) & 0xFF;
+    final long payloadStart = dataRegionStart + payloadFieldOff;
+
+    // Read isCompressed flag (1 byte)
+    this.isCompressed = page.get(ValueLayout.JAVA_BYTE, payloadStart) == 1;
+
+    // Read value length (varint)
+    final long lenOffset = payloadStart + 1;
+    final int length = DeltaVarIntCodec.decodeSignedFromSegment(page, lenOffset);
+    final int lenBytes = DeltaVarIntCodec.readSignedVarintWidth(page, lenOffset);
+
+    // Read value bytes
+    final long dataOffset = lenOffset + lenBytes;
+    this.value = new byte[length];
+    MemorySegment.copy(page, ValueLayout.JAVA_BYTE, dataOffset, this.value, 0, length);
+    this.valueParsed = true;
+  }
+
+  // ==================== DIRECT WRITE ====================
+
+  /**
+   * Encode a TextNode record directly to a MemorySegment from parameter values.
+   * Static -- reads nothing from any instance. Zero field intermediation.
+   *
+   * @param target       the target MemorySegment (reinterpreted slotted page)
+   * @param offset       absolute byte offset to write at
+   * @param heapOffsets  pre-allocated offset array (reused, FIELD_COUNT elements)
+   * @param nodeKey      the node key (delta base for structural keys)
+   * @param parentKey    the parent node key
+   * @param rightSibKey  the right sibling key
+   * @param leftSibKey   the left sibling key
+   * @param prevRev      the previous revision number
+   * @param lastModRev   the last modified revision number
+   * @param rawValue     the raw value bytes (possibly compressed)
+   * @param isCompressed whether the value is compressed
+   * @return the total number of bytes written
+   */
+  public static int writeNewRecord(final MemorySegment target, final long offset,
+      final int[] heapOffsets, final long nodeKey,
+      final long parentKey, final long rightSibKey, final long leftSibKey,
+      final int prevRev, final int lastModRev,
+      final byte[] rawValue, final boolean isCompressed) {
+    long pos = offset;
+
+    // Write nodeKind byte
+    target.set(ValueLayout.JAVA_BYTE, pos, NodeKind.TEXT.getId());
+    pos++;
+
+    // Reserve space for offset table
+    final long offsetTableStart = pos;
+    pos += FIELD_COUNT;
+
+    // Data region start
+    final long dataStart = pos;
+
+    // Field 0: parentKey (delta-varint)
+    heapOffsets[NodeFieldLayout.TEXT_PARENT_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, parentKey, nodeKey);
+
+    // Field 1: rightSiblingKey (delta-varint)
+    heapOffsets[NodeFieldLayout.TEXT_RIGHT_SIB_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, rightSibKey, nodeKey);
+
+    // Field 2: leftSiblingKey (delta-varint)
+    heapOffsets[NodeFieldLayout.TEXT_LEFT_SIB_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, leftSibKey, nodeKey);
+
+    // Field 3: prevRevision (signed varint)
+    heapOffsets[NodeFieldLayout.TEXT_PREV_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, prevRev);
+
+    // Field 4: lastModRevision (signed varint)
+    heapOffsets[NodeFieldLayout.TEXT_LAST_MOD_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, lastModRev);
+
+    // Field 5: payload [isCompressed:1][length:varint][data:bytes]
+    heapOffsets[NodeFieldLayout.TEXT_PAYLOAD] = (int) (pos - dataStart);
+    target.set(ValueLayout.JAVA_BYTE, pos, isCompressed ? (byte) 1 : (byte) 0);
+    pos++;
+    final byte[] val = rawValue != null ? rawValue : new byte[0];
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, val.length);
+    if (val.length > 0) {
+      MemorySegment.copy(val, 0, target, ValueLayout.JAVA_BYTE, pos, val.length);
+      pos += val.length;
+    }
+
+    // Write offset table
+    for (int i = 0; i < FIELD_COUNT; i++) {
+      target.set(ValueLayout.JAVA_BYTE, offsetTableStart + i, (byte) heapOffsets[i]);
+    }
+
+    return (int) (pos - offset);
+  }
+
+  /**
+   * Serialize this node from Java fields. Delegates to static writeNewRecord.
+   */
+  @Override
+  public int serializeToHeap(final MemorySegment target, final long offset) {
+    if (!metadataParsed) parseMetadataFields();
+    if (!valueParsed) parseValuePayload();
+    return writeNewRecord(target, offset, heapOffsets, nodeKey,
+        parentKey, rightSiblingKey, leftSiblingKey,
+        previousRevision, lastModifiedRevision, value, isCompressed);
+  }
+
+  /**
+   * Get the pre-allocated heap offsets array for use with static writeNewRecord.
+   */
+  public int[] getHeapOffsets() {
+    return heapOffsets;
+  }
+
+  /**
+   * Set DeweyID fields directly after creation, bypassing write-through.
+   * The DeweyID is already in the page trailer -- this just sets the Java cache fields.
+   */
+  public void setDeweyIDAfterCreation(final SirixDeweyID id, final byte[] bytes) {
+    this.sirixDeweyID = id;
+    this.deweyIDBytes = bytes;
   }
 
   @Override
@@ -164,94 +389,204 @@ public void setNodeKey(long nodeKey) {
     this.nodeKey = nodeKey;
   }
 
-  // === IMMEDIATE STRUCTURAL GETTERS (no lazy parsing) ===
+  // === STRUCTURAL GETTERS (dual-mode: flyweight or primitive) ===
 
   @Override
   public long getParentKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.TEXT_PARENT_KEY, nodeKey);
+    }
     return parentKey;
   }
 
-  public void setParentKey(long parentKey) {
+  public void setParentKey(final long parentKey) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.TEXT_PARENT_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(parentKey, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, parentKey, nodeKey);
+        return;
+      }
+      resizeParentKey(parentKey);
+      return;
+    }
     this.parentKey = parentKey;
   }
 
+  private void resizeParentKey(final long parentKey) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.TEXT_PARENT_KEY, NodeFieldLayout.TEXT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, parentKey, nodeKey));
+  }
+
   @Override
   public boolean hasParent() {
-    return parentKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getParentKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public long getRightSiblingKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.TEXT_RIGHT_SIB_KEY, nodeKey);
+    }
     return rightSiblingKey;
   }
 
-  public void setRightSiblingKey(long key) {
+  public void setRightSiblingKey(final long key) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.TEXT_RIGHT_SIB_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(key, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, key, nodeKey);
+        return;
+      }
+      resizeRightSiblingKey(key);
+      return;
+    }
     this.rightSiblingKey = key;
   }
 
+  private void resizeRightSiblingKey(final long key) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.TEXT_RIGHT_SIB_KEY, NodeFieldLayout.TEXT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, key, nodeKey));
+  }
+
   @Override
   public boolean hasRightSibling() {
-    return rightSiblingKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getRightSiblingKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public long getLeftSiblingKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.TEXT_LEFT_SIB_KEY, nodeKey);
+    }
     return leftSiblingKey;
   }
 
-  public void setLeftSiblingKey(long key) {
+  public void setLeftSiblingKey(final long key) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.TEXT_LEFT_SIB_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(key, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, key, nodeKey);
+        return;
+      }
+      resizeLeftSiblingKey(key);
+      return;
+    }
     this.leftSiblingKey = key;
   }
 
+  private void resizeLeftSiblingKey(final long key) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.TEXT_LEFT_SIB_KEY, NodeFieldLayout.TEXT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, key, nodeKey));
+  }
+
   @Override
   public boolean hasLeftSibling() {
-    return leftSiblingKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getLeftSiblingKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
-  // === LAZY GETTERS ===
+  // === LAZY GETTERS (dual-mode) ===
 
   @Override
   public int getPreviousRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.TEXT_PREV_REVISION);
+    }
     if (!metadataParsed)
       parseMetadataFields();
     return previousRevision;
   }
 
   @Override
-  public void setPreviousRevision(int revision) {
+  public void setPreviousRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.TEXT_PREV_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizePreviousRevision(revision);
+      return;
+    }
     this.previousRevision = revision;
   }
 
+  private void resizePreviousRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.TEXT_PREV_REVISION, NodeFieldLayout.TEXT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+  }
+
   @Override
   public int getLastModifiedRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.TEXT_LAST_MOD_REVISION);
+    }
     if (!metadataParsed)
       parseMetadataFields();
     return lastModifiedRevision;
   }
 
   @Override
-  public void setLastModifiedRevision(int revision) {
+  public void setLastModifiedRevision(final int revision) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.TEXT_LAST_MOD_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizeLastModifiedRevision(revision);
+      return;
+    }
     this.lastModifiedRevision = revision;
   }
 
+  private void resizeLastModifiedRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.TEXT_LAST_MOD_REVISION, NodeFieldLayout.TEXT_FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
+  }
+
   @Override
   public long getHash() {
-    if (!metadataParsed)
-      parseMetadataFields();
-    if (hash == 0L && hashFunction != null) {
-      hash = computeHash(Bytes.threadLocalHashBuffer());
+    if (hash != 0L) {
+      return hash;
     }
-    return hash;
+    // Hash not stored on page -- compute on demand from node fields
+    if (!metadataParsed) parseMetadataFields();
+    if (hashFunction != null) {
+      return computeHash(Bytes.threadLocalHashBuffer());
+    }
+    return 0L;
   }
 
   @Override
-  public void setHash(long hash) {
+  public void setHash(final long hash) {
     this.hash = hash;
   }
 
   @Override
   public byte[] getRawValue() {
-    if (!valueParsed) {
+    if (page != null && !valueParsed) {
+      readPayloadFromPage();
+    } else if (!valueParsed) {
       parseValuePayload();
     }
     if (value != null && isCompressed) {
@@ -263,7 +598,22 @@ public byte[] getRawValue() {
   }
 
   @Override
-  public void setRawValue(byte[] value) {
+  public void setRawValue(final byte[] value) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.value = value;
+      this.fixedValueEncoding = false;
+      this.fixedValueLength = 0;
+      this.fixedValueCompressed = false;
+      this.isCompressed = false;
+      this.hash = 0L;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
+    if (page != null) unbind();
     this.value = value;
     this.fixedValueEncoding = false;
     this.fixedValueLength = 0;
@@ -278,7 +628,6 @@ public void setLazyRawValue(Object source, long valueOffset, int valueLength, bo
     this.valueOffset = valueOffset;
     this.metadataParsed = true;
     this.valueParsed = false;
-    this.hasHash = false;
     this.fixedValueEncoding = true;
     this.fixedValueLength = valueLength;
     this.fixedValueCompressed = compressed;
@@ -296,6 +645,26 @@ public String getValue() {
     return new String(getRawValue(), Constants.DEFAULT_ENCODING);
   }
 
+  /**
+   * Returns the raw value bytes without triggering decompression. Used by the fixed-slot projector to
+   * preserve the original compressed bytes.
+   */
+  public byte[] getRawValueWithoutDecompression() {
+    if (page != null && !valueParsed) {
+      readPayloadFromPage();
+    } else if (!valueParsed) {
+      parseValuePayload();
+    }
+    return value;
+  }
+
+  public boolean isCompressed() {
+    if (page != null && !valueParsed) {
+      readPayloadFromPage();
+    }
+    return isCompressed;
+  }
+
   // === LEAF NODE METHODS (no children) ===
 
   @Override
@@ -384,6 +753,16 @@ public void setTypeKey(int typeKey) {
 
   @Override
   public void setDeweyID(SirixDeweyID id) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.sirixDeweyID = id;
+      this.deweyIDBytes = null;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
     this.sirixDeweyID = id;
     this.deweyIDBytes = null;
   }
@@ -413,21 +792,6 @@ public LongHashFunction getHashFunction() {
     return hashFunction;
   }
 
-  /**
-   * Returns the raw value bytes without triggering decompression. Used by the fixed-slot projector to
-   * preserve the original compressed bytes.
-   */
-  public byte[] getRawValueWithoutDecompression() {
-    if (!valueParsed) {
-      parseValuePayload();
-    }
-    return value;
-  }
-
-  public boolean isCompressed() {
-    return isCompressed;
-  }
-
   // === HASH COMPUTATION ===
 
   @Override
@@ -437,15 +801,11 @@ public long computeHash(BytesOut bytes) {
     }
 
     bytes.clear();
-    bytes.writeLong(nodeKey).writeLong(parentKey).writeByte(NodeKind.TEXT.getId());
+    bytes.writeLong(nodeKey).writeLong(getParentKey()).writeByte(NodeKind.TEXT.getId());
 
-    bytes.writeLong(leftSiblingKey).writeLong(rightSiblingKey);
     bytes.write(getRawValue());
 
-    final var buffer = ((java.nio.ByteBuffer) bytes.underlyingObject()).rewind();
-    buffer.limit((int) bytes.readLimit());
-
-    return hashFunction.hashBytes(buffer);
+    return bytes.hashDirect(hashFunction);
   }
 
   // === LAZY PARSING ===
@@ -455,6 +815,8 @@ public long computeHash(BytesOut bytes) {
    */
   public void readFrom(BytesIn source, long nodeKey, byte[] deweyId, LongHashFunction hashFunction,
       ResourceConfiguration config) {
+    // Unbind flyweight -- ensures getters use Java fields, not stale page reference
+    this.page = null;
     this.nodeKey = nodeKey;
     this.hashFunction = hashFunction;
     this.deweyIDBytes = deweyId;
@@ -470,8 +832,6 @@ public void readFrom(BytesIn source, long nodeKey, byte[] deweyId, LongHashFu
     this.lazyOffset = source.position();
     this.metadataParsed = false;
     this.valueParsed = false;
-    // Text-node hash is not serialized in compact encoding.
-    this.hasHash = false;
     this.valueOffset = 0;
     this.fixedValueEncoding = false;
     this.fixedValueLength = 0;
@@ -485,26 +845,14 @@ public void readFrom(BytesIn source, long nodeKey, byte[] deweyId, LongHashFu
     this.isCompressed = false;
   }
 
-  public void bindFixedSlotLazy(final MemorySegment slotData, final long baseOffset, final NodeKindLayout layout) {
-    this.lazyBaseOffset = baseOffset;
-    this.fixedSlotLayout = layout;
-    this.metadataParsed = false;
-  }
-
   private void parseMetadataFields() {
     if (metadataParsed) {
       return;
     }
 
-    if (fixedSlotLayout != null) {
-      final MemorySegment sd = (MemorySegment) lazySource;
-      final NodeKindLayout ly = fixedSlotLayout;
-      final long off = this.lazyBaseOffset;
-      this.previousRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.PREVIOUS_REVISION);
-      this.lastModifiedRevision = SlotLayoutAccessors.readIntField(sd, off, ly, StructuralField.LAST_MODIFIED_REVISION);
-      this.hash = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.HASH);
-      this.fixedSlotLayout = null;
-      this.metadataParsed = true;
+    if (page != null) {
+      // When bound to a page, metadata is read directly from MemorySegment via getters
+      metadataParsed = true;
       return;
     }
 
@@ -517,9 +865,6 @@ private void parseMetadataFields() {
 
     this.previousRevision = DeltaVarIntCodec.decodeSigned(bytesIn);
     this.lastModifiedRevision = DeltaVarIntCodec.decodeSigned(bytesIn);
-    if (hasHash) {
-      this.hash = bytesIn.readLong();
-    }
     this.valueOffset = bytesIn.position();
     this.metadataParsed = true;
   }
@@ -529,6 +874,11 @@ private void parseValuePayload() {
       return;
     }
 
+    if (page != null) {
+      readPayloadFromPage();
+      return;
+    }
+
     if (!metadataParsed) {
       parseMetadataFields();
     }
@@ -574,20 +924,39 @@ private BytesIn createBytesIn(long offset) {
 
   /**
    * Create a deep copy snapshot of this node.
+   * Forces parsing of all lazy fields since snapshot must be independent.
    */
   public TextNode toSnapshot() {
-    if (!metadataParsed)
+    if (page != null) {
+      // Bound mode: read all fields from page
+      if (!valueParsed) {
+        readPayloadFromPage();
+      }
+      return new TextNode(nodeKey,
+          readDeltaField(NodeFieldLayout.TEXT_PARENT_KEY, nodeKey),
+          readSignedField(NodeFieldLayout.TEXT_PREV_REVISION),
+          readSignedField(NodeFieldLayout.TEXT_LAST_MOD_REVISION),
+          readDeltaField(NodeFieldLayout.TEXT_RIGHT_SIB_KEY, nodeKey),
+          readDeltaField(NodeFieldLayout.TEXT_LEFT_SIB_KEY, nodeKey),
+          hash,
+          value != null ? value.clone() : null,
+          isCompressed,
+          hashFunction,
+          getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null);
+    }
+    // Force parse all lazy fields for snapshot (must be complete and independent)
+    if (!metadataParsed) {
       parseMetadataFields();
-    if (!valueParsed)
+    }
+    if (!valueParsed) {
       parseValuePayload();
-
-    return new TextNode(nodeKey, parentKey, previousRevision, lastModifiedRevision, rightSiblingKey, leftSiblingKey,
-        hash, value != null
-            ? value.clone()
-            : null,
-        isCompressed, hashFunction, deweyIDBytes != null
-            ? deweyIDBytes.clone()
-            : null);
+    }
+    return new TextNode(nodeKey, parentKey, previousRevision, lastModifiedRevision,
+        rightSiblingKey, leftSiblingKey, hash,
+        value != null ? value.clone() : null,
+        isCompressed,
+        hashFunction,
+        getDeweyIDAsBytes() != null ? getDeweyIDAsBytes().clone() : null);
   }
 
   @Override
@@ -597,13 +966,13 @@ public VisitResult acceptVisitor(XmlNodeVisitor visitor) {
 
   @Override
   public int hashCode() {
-    return Objects.hashCode(nodeKey, parentKey, getValue());
+    return Objects.hashCode(nodeKey, getParentKey(), getValue());
   }
 
   @Override
   public boolean equals(@Nullable Object obj) {
     if (obj instanceof TextNode other) {
-      return nodeKey == other.nodeKey && parentKey == other.parentKey
+      return nodeKey == other.nodeKey && getParentKey() == other.getParentKey()
           && java.util.Arrays.equals(getRawValue(), other.getRawValue());
     }
     return false;
@@ -613,9 +982,9 @@ public boolean equals(@Nullable Object obj) {
   public @NonNull String toString() {
     return MoreObjects.toStringHelper(this)
                       .add("nodeKey", nodeKey)
-                      .add("parentKey", parentKey)
-                      .add("rightSiblingKey", rightSiblingKey)
-                      .add("leftSiblingKey", leftSiblingKey)
+                      .add("parentKey", getParentKey())
+                      .add("rightSiblingKey", getRightSiblingKey())
+                      .add("leftSiblingKey", getLeftSiblingKey())
                       .add("value", getValue())
                       .add("compressed", isCompressed)
                       .toString();
diff --git a/bundles/sirix-core/src/main/java/io/sirix/node/xml/XmlDocumentRootNode.java b/bundles/sirix-core/src/main/java/io/sirix/node/xml/XmlDocumentRootNode.java
index e1be40235..e196cf611 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/node/xml/XmlDocumentRootNode.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/node/xml/XmlDocumentRootNode.java
@@ -41,15 +41,15 @@
 import io.sirix.node.NodeKind;
 import io.sirix.node.SirixDeweyID;
 import io.sirix.node.immutable.xml.ImmutableXmlDocumentRootNode;
+import io.sirix.node.interfaces.FlyweightNode;
 import io.sirix.node.interfaces.Node;
 import io.sirix.node.interfaces.StructNode;
 import io.sirix.node.interfaces.immutable.ImmutableXmlNode;
-import io.sirix.node.layout.NodeKindLayout;
-import io.sirix.node.layout.SlotLayoutAccessors;
-import io.sirix.node.layout.StructuralField;
+import io.sirix.page.KeyValueLeafPage;
+import io.sirix.page.NodeFieldLayout;
 import io.sirix.settings.Fixed;
-
 import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
 import net.openhft.hashing.LongHashFunction;
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
@@ -58,12 +58,12 @@
  * Node representing the root of an XML document. This node is guaranteed to exist in revision 0 and
  * cannot be removed.
  *
- * 

- * Uses primitive fields for efficient storage following the ObjectNode pattern. Document root has
- * fixed values for nodeKey (0), parentKey (-1), and no siblings.
- * 

+ * 
Uses primitive fields for efficient storage following the ObjectNode pattern.
+ * Document root has fixed values for nodeKey (0), parentKey (-1), and no siblings.

+ *
+ * 
Supports flyweight binding to a page MemorySegment for zero-copy field access.

  */
-public final class XmlDocumentRootNode implements StructNode, ImmutableXmlNode {
+public final class XmlDocumentRootNode implements StructNode, ImmutableXmlNode, FlyweightNode {
 
   // === STRUCTURAL FIELDS (immediate) ===
 
@@ -98,11 +98,43 @@ public final class XmlDocumentRootNode implements StructNode, ImmutableXmlNode {
   /** DeweyID as bytes. */
   private byte[] deweyIDBytes;
 
-  // Fixed-slot lazy support
-  private Object lazySource;
-  private long lazyBaseOffset;
-  private NodeKindLayout fixedSlotLayout;
-  private boolean lazyFieldsParsed = true;
+  // ==================== FLYWEIGHT BINDING (LeanStore page-direct access) ====================
+
+  /** Page MemorySegment when bound (null = primitive mode). */
+  private MemorySegment page;
+
+  /** Absolute byte offset of this record in the page (after HEAP_START + heapOffset). */
+  private long recordBase;
+
+  /** Absolute byte offset where the data region starts (recordBase + 1 + FIELD_COUNT). */
+  private long dataRegionStart;
+
+  /** Slot index in the page directory (for re-serialization). */
+  private int slotIndex;
+
+  /** True if this node is a factory-managed write singleton (must not be stored in records[]). */
+  private boolean writeSingleton;
+
+  /** Owning page for resize-in-place operations. */
+  private KeyValueLeafPage ownerPage;
+
+  /** Reusable offset array for serializeToHeap (avoids allocation). */
+  private final int[] heapOffsets;
+
+  private static final int FIELD_COUNT = NodeFieldLayout.XML_DOCUMENT_ROOT_FIELD_COUNT;
+
+  /**
+   * Constructor for flyweight binding.
+   * All fields except nodeKey and hashFunction will be read from page memory after bind().
+   *
+   * @param nodeKey the node key
+   * @param hashFunction the hash function from resource config
+   */
+  public XmlDocumentRootNode(long nodeKey, LongHashFunction hashFunction) {
+    this.nodeKey = nodeKey;
+    this.hashFunction = hashFunction;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
 
   /**
    * Primary constructor with all primitive fields. Used by deserialization
@@ -124,6 +156,7 @@ public XmlDocumentRootNode(long nodeKey, long firstChildKey, long lastChildKey,
     this.descendantCount = descendantCount;
     this.hashFunction = hashFunction;
     this.deweyIDBytes = SirixDeweyID.newRootID().toBytes();
+    this.heapOffsets = new int[FIELD_COUNT];
   }
 
   /**
@@ -146,6 +179,193 @@ public XmlDocumentRootNode(long nodeKey, long firstChildKey, long lastChildKey,
     this.descendantCount = descendantCount;
     this.hashFunction = hashFunction;
     this.sirixDeweyID = deweyID;
+    this.heapOffsets = new int[FIELD_COUNT];
+  }
+
+  // ==================== FLYWEIGHT BIND/UNBIND ====================
+
+  /**
+   * Bind this node as a flyweight to a page MemorySegment.
+   * When bound, getters/setters read/write directly to page memory via the offset table.
+   *
+   * @param page       the page MemorySegment
+   * @param recordBase absolute byte offset of this record in the page
+   * @param nodeKey    the node key (for delta decoding)
+   * @param slotIndex  the slot index in the page directory
+   */
+  @Override
+  public void bind(final MemorySegment page, final long recordBase, final long nodeKey,
+      final int slotIndex) {
+    this.page = page;
+    this.recordBase = recordBase;
+    this.nodeKey = nodeKey;
+    this.slotIndex = slotIndex;
+    this.dataRegionStart = recordBase + 1 + FIELD_COUNT;
+  }
+
+  /**
+   * Unbind from page memory and materialize all fields into Java primitives.
+   * After unbind, the node operates in primitive mode.
+   */
+  @Override
+  public void unbind() {
+    if (page == null) {
+      return;
+    }
+    // Materialize all fields from page to Java primitives
+    final long nk = this.nodeKey;
+    this.firstChildKey = readDeltaField(NodeFieldLayout.XDOCROOT_FIRST_CHILD_KEY, nk);
+    this.lastChildKey = readDeltaField(NodeFieldLayout.XDOCROOT_LAST_CHILD_KEY, nk);
+    this.childCount = readSignedLongField(NodeFieldLayout.XDOCROOT_CHILD_COUNT);
+    this.descendantCount = readSignedLongField(NodeFieldLayout.XDOCROOT_DESCENDANT_COUNT);
+    this.hash = readLongField(NodeFieldLayout.XDOCROOT_HASH);
+    this.ownerPage = null;
+    this.page = null;
+  }
+
+  @Override
+  public void clearBinding() {
+    this.page = null;
+    this.ownerPage = null;
+  }
+
+  /** Check if this node is bound to a page MemorySegment. */
+  @Override
+  public boolean isBound() {
+    return page != null;
+  }
+
+  @Override
+  public boolean isBoundTo(final MemorySegment page) {
+    return this.page == page;
+  }
+
+  @Override
+  public int getSlotIndex() {
+    return slotIndex;
+  }
+
+  @Override public boolean isWriteSingleton() { return writeSingleton; }
+  @Override public void setWriteSingleton(final boolean ws) { this.writeSingleton = ws; }
+  @Override public KeyValueLeafPage getOwnerPage() { return ownerPage; }
+  @Override public void setOwnerPage(final KeyValueLeafPage p) { this.ownerPage = p; }
+
+  // ==================== FLYWEIGHT FIELD READ HELPERS ====================
+
+  private long readDeltaField(final int fieldIndex, final long baseKey) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeDeltaFromSegment(page, dataRegionStart + fieldOff, baseKey);
+  }
+
+  private int readSignedField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeSignedFromSegment(page, dataRegionStart + fieldOff);
+  }
+
+  private long readSignedLongField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.decodeSignedLongFromSegment(page, dataRegionStart + fieldOff);
+  }
+
+  private long readLongField(final int fieldIndex) {
+    final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+    return DeltaVarIntCodec.readLongFromSegment(page, (int) (dataRegionStart + fieldOff));
+  }
+
+  // ==================== DIRECT WRITE ====================
+
+  /**
+   * Encode an XmlDocumentRootNode record directly to a MemorySegment from parameter values.
+   * Static -- reads nothing from any instance. Zero field intermediation.
+   *
+   * @param target          the target MemorySegment (reinterpreted slotted page)
+   * @param offset          absolute byte offset to write at
+   * @param heapOffsets     pre-allocated offset array (reused, FIELD_COUNT elements)
+   * @param nodeKey         the node key (delta base for structural keys)
+   * @param firstChildKey   the first child key
+   * @param lastChildKey    the last child key
+   * @param childCount      the child count
+   * @param descendantCount the descendant count
+   * @param hash            the hash value
+   * @return the total number of bytes written
+   */
+  public static int writeNewRecord(final MemorySegment target, final long offset,
+      final int[] heapOffsets, final long nodeKey,
+      final long firstChildKey, final long lastChildKey,
+      final long childCount, final long descendantCount, final long hash) {
+    long pos = offset;
+
+    // Write nodeKind byte
+    target.set(ValueLayout.JAVA_BYTE, pos, NodeKind.XML_DOCUMENT.getId());
+    pos++;
+
+    // Reserve space for offset table
+    final long offsetTableStart = pos;
+    pos += FIELD_COUNT;
+
+    // Data region start
+    final long dataStart = pos;
+
+    // Field 0: firstChildKey (delta-varint from nodeKey)
+    heapOffsets[NodeFieldLayout.XDOCROOT_FIRST_CHILD_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, firstChildKey, nodeKey);
+
+    // Field 1: lastChildKey (delta-varint from nodeKey)
+    heapOffsets[NodeFieldLayout.XDOCROOT_LAST_CHILD_KEY] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeDeltaToSegment(target, pos, lastChildKey, nodeKey);
+
+    // Field 2: childCount (signed long varint)
+    heapOffsets[NodeFieldLayout.XDOCROOT_CHILD_COUNT] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedLongToSegment(target, pos, childCount);
+
+    // Field 3: descendantCount (signed long varint)
+    heapOffsets[NodeFieldLayout.XDOCROOT_DESCENDANT_COUNT] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedLongToSegment(target, pos, descendantCount);
+
+    // Field 4: previousRevision (signed varint) -- always 0 for document root
+    heapOffsets[NodeFieldLayout.XDOCROOT_PREV_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, 0);
+
+    // Field 5: lastModifiedRevision (signed varint) -- always 0 for document root
+    heapOffsets[NodeFieldLayout.XDOCROOT_LAST_MOD_REVISION] = (int) (pos - dataStart);
+    pos += DeltaVarIntCodec.writeSignedToSegment(target, pos, 0);
+
+    // Field 6: hash (fixed 8 bytes)
+    heapOffsets[NodeFieldLayout.XDOCROOT_HASH] = (int) (pos - dataStart);
+    DeltaVarIntCodec.writeLongToSegment(target, pos, hash);
+    pos += Long.BYTES;
+
+    // Write offset table
+    for (int i = 0; i < FIELD_COUNT; i++) {
+      target.set(ValueLayout.JAVA_BYTE, offsetTableStart + i, (byte) heapOffsets[i]);
+    }
+
+    return (int) (pos - offset);
+  }
+
+  /**
+   * Serialize this node from Java fields. Delegates to static writeNewRecord.
+   */
+  @Override
+  public int serializeToHeap(final MemorySegment target, final long offset) {
+    return writeNewRecord(target, offset, heapOffsets, nodeKey,
+        firstChildKey, lastChildKey, childCount, descendantCount, hash);
+  }
+
+  /**
+   * Get the pre-allocated heap offsets array for use with static writeNewRecord.
+   */
+  public int[] getHeapOffsets() {
+    return heapOffsets;
+  }
+
+  /**
+   * Set DeweyID fields directly after creation, bypassing write-through.
+   * The DeweyID is already in the page trailer -- this just sets the Java cache fields.
+   */
+  public void setDeweyIDAfterCreation(final SirixDeweyID id, final byte[] bytes) {
+    this.sirixDeweyID = id;
+    this.deweyIDBytes = bytes;
   }
 
   @Override
@@ -210,83 +430,155 @@ public boolean hasLeftSibling() {
 
   @Override
   public long getFirstChildKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.XDOCROOT_FIRST_CHILD_KEY, nodeKey);
+    }
     return firstChildKey;
   }
 
   @Override
   public void setFirstChildKey(long key) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.XDOCROOT_FIRST_CHILD_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(key, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, key, nodeKey);
+        return;
+      }
+      resizeFirstChildKey(key);
+      return;
+    }
     this.firstChildKey = key;
   }
 
+  private void resizeFirstChildKey(final long key) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.XDOCROOT_FIRST_CHILD_KEY, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, key, nodeKey));
+  }
+
   @Override
   public boolean hasFirstChild() {
-    return firstChildKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getFirstChildKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public long getLastChildKey() {
+    if (page != null) {
+      return readDeltaField(NodeFieldLayout.XDOCROOT_LAST_CHILD_KEY, nodeKey);
+    }
     return lastChildKey;
   }
 
   @Override
   public void setLastChildKey(long key) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.XDOCROOT_LAST_CHILD_KEY) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readDeltaEncodedWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeDeltaEncodedWidth(key, nodeKey);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeDeltaToSegment(page, absOff, key, nodeKey);
+        return;
+      }
+      resizeLastChildKey(key);
+      return;
+    }
     this.lastChildKey = key;
   }
 
+  private void resizeLastChildKey(final long key) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.XDOCROOT_LAST_CHILD_KEY, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeDeltaToSegment(target, off, key, nodeKey));
+  }
+
   @Override
   public boolean hasLastChild() {
-    return lastChildKey != Fixed.NULL_NODE_KEY.getStandardProperty();
+    return getLastChildKey() != Fixed.NULL_NODE_KEY.getStandardProperty();
   }
 
   @Override
   public long getChildCount() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
+    if (page != null) {
+      return readSignedLongField(NodeFieldLayout.XDOCROOT_CHILD_COUNT);
+    }
     return childCount;
   }
 
   public void setChildCount(long childCount) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.XDOCROOT_CHILD_COUNT) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedLongEncodedWidth(childCount);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedLongToSegment(page, absOff, childCount);
+        return;
+      }
+      resizeChildCount(childCount);
+      return;
+    }
     this.childCount = childCount;
   }
 
+  private void resizeChildCount(final long childCount) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.XDOCROOT_CHILD_COUNT, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedLongToSegment(target, off, childCount));
+  }
+
   @Override
   public void incrementChildCount() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
-    childCount++;
+    setChildCount(getChildCount() + 1);
   }
 
   @Override
   public void decrementChildCount() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
-    childCount--;
+    setChildCount(getChildCount() - 1);
   }
 
   @Override
   public long getDescendantCount() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
+    if (page != null) {
+      return readSignedLongField(NodeFieldLayout.XDOCROOT_DESCENDANT_COUNT);
+    }
     return descendantCount;
   }
 
   @Override
   public void setDescendantCount(long descendantCount) {
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.XDOCROOT_DESCENDANT_COUNT) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedLongEncodedWidth(descendantCount);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedLongToSegment(page, absOff, descendantCount);
+        return;
+      }
+      resizeDescendantCount(descendantCount);
+      return;
+    }
     this.descendantCount = descendantCount;
   }
 
+  private void resizeDescendantCount(final long descendantCount) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.XDOCROOT_DESCENDANT_COUNT, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedLongToSegment(target, off, descendantCount));
+  }
+
   @Override
   public void incrementDescendantCount() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
-    descendantCount++;
+    setDescendantCount(getDescendantCount() + 1);
   }
 
   @Override
   public void decrementDescendantCount() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
-    descendantCount--;
+    setDescendantCount(getDescendantCount() - 1);
   }
 
   @Override
@@ -296,33 +588,47 @@ public long computeHash(BytesOut bytes) {
     }
 
     bytes.clear();
-    bytes.writeLong(nodeKey).writeLong(getParentKey()).writeByte(getKind().getId());
+    bytes.writeLong(nodeKey)
+         .writeLong(getParentKey())
+         .writeByte(getKind().getId());
 
-    bytes.writeLong(childCount)
-         .writeLong(descendantCount)
+    bytes.writeLong(getChildCount())
+         .writeLong(getDescendantCount())
          .writeLong(getLeftSiblingKey())
          .writeLong(getRightSiblingKey())
-         .writeLong(firstChildKey);
+         .writeLong(getFirstChildKey());
 
-    if (lastChildKey != Fixed.INVALID_KEY_FOR_TYPE_CHECK.getStandardProperty()) {
-      bytes.writeLong(lastChildKey);
+    if (getLastChildKey() != Fixed.INVALID_KEY_FOR_TYPE_CHECK.getStandardProperty()) {
+      bytes.writeLong(getLastChildKey());
     }
 
-    final var buffer = ((java.nio.ByteBuffer) bytes.underlyingObject()).rewind();
-    buffer.limit((int) bytes.readLimit());
-
-    return hashFunction.hashBytes(buffer);
+    return bytes.hashDirect(hashFunction);
   }
 
   @Override
   public void setHash(long hash) {
+    if (page != null) {
+      // Hash is ALWAYS in-place (fixed 8 bytes)
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE,
+          recordBase + 1 + NodeFieldLayout.XDOCROOT_HASH) & 0xFF;
+      DeltaVarIntCodec.writeLongToSegment(page, dataRegionStart + fieldOff, hash);
+      return;
+    }
     this.hash = hash;
   }
 
   @Override
   public long getHash() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
+    if (page != null) {
+      final long h = readLongField(NodeFieldLayout.XDOCROOT_HASH);
+      if (h != 0L) return h;
+      if (hashFunction != null) {
+        final long computed = computeHash(Bytes.threadLocalHashBuffer());
+        setHash(computed);
+        return computed;
+      }
+      return 0L;
+    }
     if (hash == 0L && hashFunction != null) {
       hash = computeHash(Bytes.threadLocalHashBuffer());
     }
@@ -331,22 +637,64 @@ public long getHash() {
 
   @Override
   public int getPreviousRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.XDOCROOT_PREV_REVISION);
+    }
     return 0; // Document root is always in revision 0
   }
 
   @Override
   public void setPreviousRevision(int revision) {
-    // Document root doesn't track previous revision
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.XDOCROOT_PREV_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizePreviousRevision(revision);
+      return;
+    }
+    // Document root doesn't track previous revision in primitive mode
+  }
+
+  private void resizePreviousRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.XDOCROOT_PREV_REVISION, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
   }
 
   @Override
   public int getLastModifiedRevisionNumber() {
+    if (page != null) {
+      return readSignedField(NodeFieldLayout.XDOCROOT_LAST_MOD_REVISION);
+    }
     return 0;
   }
 
   @Override
   public void setLastModifiedRevision(int revision) {
-    // Document root doesn't track last modified revision
+    if (page != null) {
+      final int fieldOff = page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + NodeFieldLayout.XDOCROOT_LAST_MOD_REVISION) & 0xFF;
+      final long absOff = dataRegionStart + fieldOff;
+      final int currentWidth = DeltaVarIntCodec.readSignedVarintWidth(page, absOff);
+      final int newWidth = DeltaVarIntCodec.computeSignedEncodedWidth(revision);
+      if (newWidth == currentWidth) {
+        DeltaVarIntCodec.writeSignedToSegment(page, absOff, revision);
+        return;
+      }
+      resizeLastModifiedRevision(revision);
+      return;
+    }
+    // Document root doesn't track last modified revision in primitive mode
+  }
+
+  private void resizeLastModifiedRevision(final int revision) {
+    ownerPage.resizeRecordField(this, nodeKey, slotIndex,
+        NodeFieldLayout.XDOCROOT_LAST_MOD_REVISION, FIELD_COUNT,
+        (target, off) -> DeltaVarIntCodec.writeSignedToSegment(target, off, revision));
   }
 
   @Override
@@ -388,6 +736,16 @@ public byte[] getDeweyIDAsBytes() {
 
   @Override
   public void setDeweyID(SirixDeweyID id) {
+    final var owner = this.ownerPage;
+    if (owner != null) {
+      final long nk = this.nodeKey;
+      final int slot = this.slotIndex;
+      unbind();
+      this.sirixDeweyID = id;
+      this.deweyIDBytes = null;
+      owner.resizeRecord(this, nk, slot);
+      return;
+    }
     this.sirixDeweyID = id;
     this.deweyIDBytes = null;
   }
@@ -411,6 +769,9 @@ public LongHashFunction getHashFunction() {
    */
   public void readFrom(BytesIn source, long nodeKey, byte[] deweyId, LongHashFunction hashFunction,
       ResourceConfiguration config) {
+    // Unbind flyweight -- ensures getters use Java fields, not stale page reference
+    this.page = null;
+
     final long firstChildKey = DeltaVarIntCodec.decodeDelta(source, nodeKey);
     final long childCount = firstChildKey == Fixed.NULL_NODE_KEY.getStandardProperty()
         ? 0L
@@ -437,43 +798,33 @@ public void readFrom(BytesIn source, long nodeKey, byte[] deweyId, LongHashFu
     this.sirixDeweyID = null;
   }
 
-  public void bindFixedSlotLazy(final MemorySegment slotData, final long baseOffset, final NodeKindLayout layout) {
-    this.lazyBaseOffset = baseOffset;
-    this.lazySource = slotData;
-    this.fixedSlotLayout = layout;
-    this.lazyFieldsParsed = false;
-  }
-
-  private void parseLazyFields() {
-    if (lazyFieldsParsed) {
-      return;
-    }
-
-    if (fixedSlotLayout != null) {
-      final MemorySegment sd = (MemorySegment) lazySource;
-      final NodeKindLayout ly = fixedSlotLayout;
-      final long off = this.lazyBaseOffset;
-      this.childCount = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.CHILD_COUNT);
-      this.descendantCount = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.DESCENDANT_COUNT);
-      this.hash = SlotLayoutAccessors.readLongField(sd, off, ly, StructuralField.HASH);
-      this.fixedSlotLayout = null;
-      this.lazyFieldsParsed = true;
-      return;
-    }
-
-    this.lazyFieldsParsed = true;
-  }
-
   /**
    * Create a deep copy snapshot of this node.
    *
    * @return a new instance with copied values
    */
   public XmlDocumentRootNode toSnapshot() {
-    if (!lazyFieldsParsed)
-      parseLazyFields();
-    final XmlDocumentRootNode snapshot =
-        new XmlDocumentRootNode(nodeKey, firstChildKey, lastChildKey, childCount, descendantCount, hashFunction);
+    if (page != null) {
+      // Bound mode: read all fields from page
+      final long nk = this.nodeKey;
+      final XmlDocumentRootNode snapshot = new XmlDocumentRootNode(
+          nk,
+          readDeltaField(NodeFieldLayout.XDOCROOT_FIRST_CHILD_KEY, nk),
+          readDeltaField(NodeFieldLayout.XDOCROOT_LAST_CHILD_KEY, nk),
+          readSignedLongField(NodeFieldLayout.XDOCROOT_CHILD_COUNT),
+          readSignedLongField(NodeFieldLayout.XDOCROOT_DESCENDANT_COUNT),
+          hashFunction);
+      snapshot.hash = readLongField(NodeFieldLayout.XDOCROOT_HASH);
+      if (deweyIDBytes != null) {
+        snapshot.deweyIDBytes = deweyIDBytes.clone();
+      }
+      if (sirixDeweyID != null) {
+        snapshot.sirixDeweyID = sirixDeweyID;
+      }
+      return snapshot;
+    }
+    final XmlDocumentRootNode snapshot = new XmlDocumentRootNode(
+        nodeKey, firstChildKey, lastChildKey, childCount, descendantCount, hashFunction);
     snapshot.hash = this.hash;
     if (deweyIDBytes != null) {
       snapshot.deweyIDBytes = deweyIDBytes.clone();
diff --git a/bundles/sirix-core/src/main/java/io/sirix/page/FlyweightNodeFactory.java b/bundles/sirix-core/src/main/java/io/sirix/page/FlyweightNodeFactory.java
new file mode 100644
index 000000000..5560ae37b
--- /dev/null
+++ b/bundles/sirix-core/src/main/java/io/sirix/page/FlyweightNodeFactory.java
@@ -0,0 +1,92 @@
+package io.sirix.page;
+
+import io.sirix.node.interfaces.FlyweightNode;
+import io.sirix.node.json.ArrayNode;
+import io.sirix.node.json.BooleanNode;
+import io.sirix.node.json.JsonDocumentRootNode;
+import io.sirix.node.json.NullNode;
+import io.sirix.node.json.NumberNode;
+import io.sirix.node.json.ObjectBooleanNode;
+import io.sirix.node.json.ObjectKeyNode;
+import io.sirix.node.json.ObjectNode;
+import io.sirix.node.json.ObjectNullNode;
+import io.sirix.node.json.ObjectNumberNode;
+import io.sirix.node.json.ObjectStringNode;
+import io.sirix.node.json.StringNode;
+import io.sirix.node.xml.AttributeNode;
+import io.sirix.node.xml.CommentNode;
+import io.sirix.node.xml.ElementNode;
+import io.sirix.node.xml.NamespaceNode;
+import io.sirix.node.xml.PINode;
+import io.sirix.node.xml.TextNode;
+import io.sirix.node.xml.XmlDocumentRootNode;
+import net.openhft.hashing.LongHashFunction;
+
+import java.lang.foreign.MemorySegment;
+
+/**
+ * Factory for creating flyweight node shells and binding them to a slotted page MemorySegment.
+ *
+ * 
This factory creates minimal node instances (binding shells) that are immediately
+ * bound to a record in the page heap. After binding, all getters/setters operate
+ * directly on page memory via the per-record offset table.

+ */
+public final class FlyweightNodeFactory {
+
+  private FlyweightNodeFactory() {
+    throw new AssertionError("Utility class");
+  }
+
+  /**
+   * Create a flyweight node shell and bind it to a record in the slotted page.
+   *
+   * @param page         the slotted page MemorySegment
+   * @param slotIndex    the slot index (0 to 1023)
+   * @param nodeKey      the node key for this record
+   * @param hashFunction the hash function from resource config
+   * @return the bound flyweight node
+   * @throws IllegalArgumentException if the nodeKindId is not a known flyweight type
+   */
+  public static FlyweightNode createAndBind(final MemorySegment page, final int slotIndex,
+      final long nodeKey, final LongHashFunction hashFunction) {
+    final int heapOffset = PageLayout.getDirHeapOffset(page, slotIndex);
+    final int nodeKindId = PageLayout.getDirNodeKindId(page, slotIndex);
+    final long recordBase = PageLayout.heapAbsoluteOffset(heapOffset);
+
+    final FlyweightNode node = createShell(nodeKindId, nodeKey, hashFunction);
+    node.bind(page, recordBase, nodeKey, slotIndex);
+    return node;
+  }
+
+  /**
+   * Create a minimal flyweight node shell for binding.
+   * The shell has only nodeKey and hashFunction initialized.
+   * All other fields will be read from page memory after bind().
+   */
+  private static FlyweightNode createShell(final int nodeKindId, final long nodeKey,
+      final LongHashFunction hashFunction) {
+    return switch (nodeKindId) {
+      case 1  -> new ElementNode(nodeKey, hashFunction);          // ELEMENT
+      case 2  -> new AttributeNode(nodeKey, hashFunction);        // ATTRIBUTE
+      case 3  -> new TextNode(nodeKey, hashFunction);             // TEXT
+      case 7  -> new PINode(nodeKey, hashFunction);               // PROCESSING_INSTRUCTION
+      case 8  -> new CommentNode(nodeKey, hashFunction);          // COMMENT
+      case 9  -> new XmlDocumentRootNode(nodeKey, hashFunction);  // XML_DOCUMENT
+      case 13 -> new NamespaceNode(nodeKey, hashFunction);        // NAMESPACE
+      case 24 -> new ObjectNode(nodeKey, hashFunction);           // OBJECT
+      case 25 -> new ArrayNode(nodeKey, hashFunction);            // ARRAY
+      case 26 -> new ObjectKeyNode(nodeKey, hashFunction);        // OBJECT_KEY
+      case 27 -> new BooleanNode(nodeKey, hashFunction);          // BOOLEAN_VALUE
+      case 28 -> new NumberNode(nodeKey, hashFunction);           // NUMBER_VALUE
+      case 29 -> new NullNode(nodeKey, hashFunction);             // NULL_VALUE
+      case 30 -> new StringNode(nodeKey, hashFunction);           // STRING_VALUE
+      case 31 -> new JsonDocumentRootNode(nodeKey, hashFunction); // JSON_DOCUMENT
+      case 40 -> new ObjectStringNode(nodeKey, hashFunction);     // OBJECT_STRING_VALUE
+      case 41 -> new ObjectBooleanNode(nodeKey, hashFunction);    // OBJECT_BOOLEAN_VALUE
+      case 42 -> new ObjectNumberNode(nodeKey, hashFunction);     // OBJECT_NUMBER_VALUE
+      case 43 -> new ObjectNullNode(nodeKey, hashFunction);       // OBJECT_NULL_VALUE
+      default -> throw new IllegalArgumentException(
+          "Unknown flyweight node kind ID: " + nodeKindId);
+    };
+  }
+}
diff --git a/bundles/sirix-core/src/main/java/io/sirix/page/KeyValueLeafPage.java b/bundles/sirix-core/src/main/java/io/sirix/page/KeyValueLeafPage.java
index 0ebe7310d..1cf37cc72 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/page/KeyValueLeafPage.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/page/KeyValueLeafPage.java
@@ -9,17 +9,14 @@
 import io.sirix.cache.MemorySegmentAllocator;
 import io.sirix.cache.WindowsMemorySegmentAllocator;
 import io.sirix.index.IndexType;
+import io.sirix.node.DeltaVarIntCodec;
 import io.sirix.node.NodeKind;
 import io.sirix.node.interfaces.DataRecord;
 import io.sirix.node.interfaces.DeweyIdSerializer;
+import io.sirix.node.interfaces.FlyweightNode;
 import io.sirix.node.interfaces.RecordSerializer;
 import io.sirix.node.json.ObjectStringNode;
 import io.sirix.node.json.StringNode;
-import io.sirix.node.layout.FixedToCompactTransformer;
-import io.sirix.node.xml.AttributeNode;
-import io.sirix.node.xml.CommentNode;
-import io.sirix.node.xml.PINode;
-import io.sirix.node.xml.TextNode;
 import io.sirix.page.interfaces.KeyValuePage;
 import io.sirix.settings.Constants;
 import io.sirix.settings.DiagnosticSettings;
@@ -28,7 +25,6 @@
 import io.sirix.utils.ArrayIterator;
 import io.sirix.utils.OS;
 import io.sirix.node.BytesOut;
-import io.sirix.node.MemorySegmentBytesIn;
 import io.sirix.node.MemorySegmentBytesOut;
 import org.checkerframework.checker.index.qual.NonNegative;
 import org.checkerframework.checker.nullness.qual.NonNull;
@@ -45,7 +41,6 @@
 import java.lang.foreign.ValueLayout;
 import java.lang.invoke.MethodHandles;
 import java.lang.invoke.VarHandle;
-import java.nio.ByteOrder;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
@@ -64,66 +59,62 @@
  * The page currently is not thread safe (might have to be for concurrent write-transactions)!
  * 

  */
-@SuppressWarnings({"unchecked"})
+@SuppressWarnings({ "unchecked" })
 public final class KeyValueLeafPage implements KeyValuePage {
 
   private static final Logger LOGGER = LoggerFactory.getLogger(KeyValueLeafPage.class);
   private static final int INT_SIZE = Integer.BYTES;
-
+  
   /**
-   * SIMD vector species for bitmap operations. Uses the preferred species for the current platform
-   * (256-bit AVX2 or 512-bit AVX-512).
+   * SIMD vector species for bitmap operations.
+   * Uses the preferred species for the current platform (256-bit AVX2 or 512-bit AVX-512).
    */
   private static final VectorSpecies LONG_SPECIES = LongVector.SPECIES_PREFERRED;
-
-  /**
-   * Unaligned int layout for zero-copy deserialization. When slotMemory is a slice of the
-   * decompression buffer, it may not be 4-byte aligned.
-   */
-  private static final ValueLayout.OfInt JAVA_INT_UNALIGNED = ValueLayout.JAVA_INT.withByteAlignment(1);
-
+  
+  
   /**
-   * Enable detailed memory leak tracking. Accessed via centralized
-   * {@link DiagnosticSettings#MEMORY_LEAK_TRACKING}.
+   * Enable detailed memory leak tracking.
+   * Accessed via centralized {@link DiagnosticSettings#MEMORY_LEAK_TRACKING}.
    * 
    * @see DiagnosticSettings#isMemoryLeakTrackingEnabled()
    */
   public static final boolean DEBUG_MEMORY_LEAKS = DiagnosticSettings.MEMORY_LEAK_TRACKING;
-
+  
   // DIAGNOSTIC COUNTERS (enabled via DEBUG_MEMORY_LEAKS)
-  public static final java.util.concurrent.atomic.AtomicLong PAGES_CREATED =
-      new java.util.concurrent.atomic.AtomicLong(0);
-  public static final java.util.concurrent.atomic.AtomicLong PAGES_CLOSED =
-      new java.util.concurrent.atomic.AtomicLong(0);
-  public static final java.util.concurrent.ConcurrentHashMap PAGES_BY_TYPE =
-      new java.util.concurrent.ConcurrentHashMap<>();
-  public static final java.util.concurrent.ConcurrentHashMap PAGES_CLOSED_BY_TYPE =
-      new java.util.concurrent.ConcurrentHashMap<>();
-
+  public static final java.util.concurrent.atomic.AtomicLong PAGES_CREATED = new java.util.concurrent.atomic.AtomicLong(0);
+  public static final java.util.concurrent.atomic.AtomicLong PAGES_CLOSED = new java.util.concurrent.atomic.AtomicLong(0);
+  public static final java.util.concurrent.ConcurrentHashMap PAGES_BY_TYPE = 
+    new java.util.concurrent.ConcurrentHashMap<>();
+  public static final java.util.concurrent.ConcurrentHashMap PAGES_CLOSED_BY_TYPE = 
+    new java.util.concurrent.ConcurrentHashMap<>();
+  
   // TRACK ALL LIVE PAGES - for leak detection (use object identity, not recordPageKey)
   // CRITICAL: Use IdentityHashMap to track by object identity, not equals/hashCode
-  public static final java.util.Set ALL_LIVE_PAGES =
-      java.util.Collections.synchronizedSet(java.util.Collections.newSetFromMap(new java.util.IdentityHashMap<>()));
-
+  public static final java.util.Set ALL_LIVE_PAGES = 
+    java.util.Collections.synchronizedSet(
+      java.util.Collections.newSetFromMap(new java.util.IdentityHashMap<>())
+    );
+  
   // LEAK DETECTION: Track finalized pages
-  public static final java.util.concurrent.atomic.AtomicLong PAGES_FINALIZED_WITHOUT_CLOSE =
-      new java.util.concurrent.atomic.AtomicLong(0);
-
+  public static final java.util.concurrent.atomic.AtomicLong PAGES_FINALIZED_WITHOUT_CLOSE = new java.util.concurrent.atomic.AtomicLong(0);
+  
   // Track finalized pages by type and pageKey for diagnostics
-  public static final java.util.concurrent.ConcurrentHashMap FINALIZED_BY_TYPE =
-      new java.util.concurrent.ConcurrentHashMap<>();
-  public static final java.util.concurrent.ConcurrentHashMap FINALIZED_BY_PAGE_KEY =
-      new java.util.concurrent.ConcurrentHashMap<>();
-
+  public static final java.util.concurrent.ConcurrentHashMap FINALIZED_BY_TYPE = 
+    new java.util.concurrent.ConcurrentHashMap<>();
+  public static final java.util.concurrent.ConcurrentHashMap FINALIZED_BY_PAGE_KEY = 
+    new java.util.concurrent.ConcurrentHashMap<>();
+    
   // Track all Page 0 instances for explicit cleanup
   // CRITICAL: Use synchronized IdentityHashSet to track by object identity, not equals/hashCode
   // (Multiple Page 0 instances with same recordPageKey/revision would collide in regular Set)
-  public static final java.util.Set ALL_PAGE_0_INSTANCES =
-      java.util.Collections.synchronizedSet(java.util.Collections.newSetFromMap(new java.util.IdentityHashMap<>()));
-
+  public static final java.util.Set ALL_PAGE_0_INSTANCES = 
+    java.util.Collections.synchronizedSet(
+      java.util.Collections.newSetFromMap(new java.util.IdentityHashMap<>())
+    );
+  
   /**
-   * Version counter for detecting page reuse (LeanStore/Umbra approach). Incremented when page is
-   * evicted and reused for a different logical page.
+   * Version counter for detecting page reuse (LeanStore/Umbra approach).
+   * Incremented when page is evicted and reused for a different logical page.
    */
   private final AtomicInteger version = new AtomicInteger(0);
 
@@ -140,8 +131,8 @@ public final class KeyValueLeafPage implements KeyValuePage {
   private static final int CLOSED_BIT = 4;
 
   /**
-   * Packed state flags: HOT (bit 0), orphaned (bit 1), closed (bit 2). Accessed via VarHandle for
-   * lock-free CAS operations.
+   * Packed state flags: HOT (bit 0), orphaned (bit 1), closed (bit 2).
+   * Accessed via VarHandle for lock-free CAS operations.
    */
   @SuppressWarnings("unused") // Accessed via VarHandle
   private volatile int stateFlags = 0;
@@ -151,28 +142,28 @@ public final class KeyValueLeafPage implements KeyValuePage {
 
   static {
     try {
-      STATE_FLAGS_HANDLE = MethodHandles.lookup().findVarHandle(KeyValueLeafPage.class, "stateFlags", int.class);
+      STATE_FLAGS_HANDLE = MethodHandles.lookup()
+          .findVarHandle(KeyValueLeafPage.class, "stateFlags", int.class);
     } catch (NoSuchFieldException | IllegalAccessException e) {
       throw new ExceptionInInitializerError(e);
     }
   }
 
   /**
-   * Guard count for preventing eviction during active use (LeanStore/Umbra pattern). Pages with
-   * guardCount > 0 cannot be evicted. This is simpler than per-transaction pinning - it's just a
-   * reference count.
+   * Guard count for preventing eviction during active use (LeanStore/Umbra pattern).
+   * Pages with guardCount > 0 cannot be evicted.
+   * This is simpler than per-transaction pinning - it's just a reference count.
    */
   private final AtomicInteger guardCount = new AtomicInteger(0);
 
   /**
-   * DIAGNOSTIC: Stack trace of where this page was created (only captured when
-   * DEBUG_MEMORY_LEAKS=true). Used to trace where leaked pages come from.
+   * DIAGNOSTIC: Stack trace of where this page was created (only captured when DEBUG_MEMORY_LEAKS=true).
+   * Used to trace where leaked pages come from.
    */
   private final StackTraceElement[] creationStackTrace;
 
   /**
    * Get the creation stack trace for leak diagnostics.
-   * 
    * @return stack trace from constructor, or null if DEBUG_MEMORY_LEAKS disabled
    */
   public StackTraceElement[] getCreationStackTrace() {
@@ -189,17 +180,7 @@ public StackTraceElement[] getCreationStackTrace() {
    */
   private boolean areDeweyIDsStored;
 
-  private final boolean doResizeMemorySegmentsIfNeeded;
 
-  /**
-   * Start of free space.
-   */
-  private int slotMemoryFreeSpaceStart;
-
-  /**
-   * Start of free space.
-   */
-  private int deweyIdMemoryFreeSpaceStart;
 
   /**
    * Start of free space for string values.
@@ -229,7 +210,7 @@ public StackTraceElement[] getCreationStackTrace() {
   /**
    * References to overflow pages.
    */
-  private volatile Map references;
+  private final Map references;
 
   /**
    * Key of record page. This is the base key of all contained nodes.
@@ -241,54 +222,25 @@ public StackTraceElement[] getCreationStackTrace() {
    */
   private final DataRecord[] records;
 
-  /**
-   * Number of records currently materialized in {@link #records}.
-   */
-  private int inMemoryRecordCount;
-
-  /**
-   * Adaptive in-memory demotion policy constants.
-   */
-  private static final int MIN_DEMOTION_THRESHOLD = 64;
-  private static final int MAX_DEMOTION_THRESHOLD = 256;
-  private static final int DEMOTION_STEP = 32;
-
-  /**
-   * Current adaptive threshold for demoting materialized records to slot memory.
-   */
-  private int demotionThreshold = MIN_DEMOTION_THRESHOLD;
-
-  /**
-   * Number of records re-materialized from slot memory since last demotion.
-   */
-  private int rematerializedRecordsSinceLastDemotion;
-
-  /**
-   * Memory segment for slots and Dewey IDs.
-   */
-  private MemorySegment slotMemory;
-  private MemorySegment deweyIdMemory;
 
   /**
-   * Memory segment for string values (columnar storage for better compression). Stores all string
-   * content contiguously, separate from node metadata in slotMemory.
+   * Memory segment for string values (columnar storage for better compression).
+   * Stores all string content contiguously, separate from node metadata.
    */
   private MemorySegment stringValueMemory;
 
   /**
-   * FSST symbol table for string compression (shared across all strings in page). Null if FSST
-   * compression is not used.
+   * FSST symbol table for string compression (shared across all strings in page).
+   * Null if FSST compression is not used.
    */
   private byte[] fsstSymbolTable;
 
-  /** Pre-parsed FSST symbol table (avoids re-parsing on every encode/decode). */
-  private byte[][] parsedFsstSymbols;
+  /** Reusable flyweight for FSST compression of StringNode slots on slotted page. */
+  private final StringNode fsstStringFlyweight = new StringNode(0, null);
+
+  /** Reusable flyweight for FSST compression of ObjectStringNode slots on slotted page. */
+  private final ObjectStringNode fsstObjStringFlyweight = new ObjectStringNode(0, null);
 
-  /**
-   * Offset arrays to manage positions within memory segments.
-   */
-  private final int[] slotOffsets;
-  private final int[] deweyIdOffsets;
 
   /**
    * Offset array for string values (maps slot -> offset in stringValueMemory).
@@ -296,45 +248,29 @@ public StackTraceElement[] getCreationStackTrace() {
   private final int[] stringValueOffsets;
 
   /**
-   * Bitmap tracking which slots are populated (16 longs = 1024 bits). Bit i is set iff slotOffsets[i]
-   * >= 0. Used for O(k) iteration over populated slots instead of O(1024).
+   * Bitmap tracking which slots are populated (16 longs = 1024 bits).
+   * Used for O(k) iteration over populated slots instead of O(1024).
+   * Materialized from the slotted page bitmap when needed.
    */
   private final long[] slotBitmap;
 
-  /**
-   * Bitmap tracking which populated slots are currently stored in fixed in-memory layout. Bit i set
-   * => slot i contains fixed-layout bytes (not compact varint/delta bytes).
-   */
-  private final long[] fixedFormatBitmap;
-
-  /**
-   * Node kind id for fixed-format slots, indexed by slot number. Entries are
-   * {@link #NO_FIXED_SLOT_KIND} for compact slots or unknown fixed slots.
-   */
-  private final byte[] fixedSlotKinds;
-
   /**
    * Number of words in the slot bitmap (16 words * 64 bits = 1024 slots).
    */
   private static final int BITMAP_WORDS = 16;
 
   /**
-   * Sentinel for "no fixed slot kind assigned".
-   */
-  private static final byte NO_FIXED_SLOT_KIND = (byte) -1;
-
-  /**
-   * Bitmap tracking which slots need preservation during lazy copy (16 longs = 1024 bits). Used by
-   * DIFFERENTIAL, INCREMENTAL (full-dump), and SLIDING_SNAPSHOT versioning. Null means no
-   * preservation needed (e.g., INCREMENTAL non-full-dump or FULL versioning). At commit time, slots
-   * marked here but not in records[] are copied from completePageRef.
+   * Bitmap tracking which slots need preservation during lazy copy (16 longs = 1024 bits).
+   * Used by DIFFERENTIAL, INCREMENTAL (full-dump), and SLIDING_SNAPSHOT versioning.
+   * Null means no preservation needed (e.g., INCREMENTAL non-full-dump or FULL versioning).
+   * At commit time, slots marked here but not in records[] are copied from completePageRef.
    */
   private long[] preservationBitmap;
 
   /**
-   * Reference to the complete page for lazy slot copying at commit time. Set during
-   * combineRecordPagesForModification, used by addReferences() to copy slots that need preservation
-   * but weren't modified (records[i] == null).
+   * Reference to the complete page for lazy slot copying at commit time.
+   * Set during combineRecordPagesForModification, used by addReferences() to copy
+   * slots that need preservation but weren't modified (records[i] == null).
    */
   private KeyValueLeafPage completePageRef;
 
@@ -355,6 +291,10 @@ public StackTraceElement[] getCreationStackTrace() {
 
   private volatile BytesOut bytes;
 
+  /** Compressed page data as MemorySegment (zero-copy path). Arena.ofAuto()-managed. */
+  private volatile MemorySegment compressedSegment;
+
+
   private volatile byte[] hashCode;
 
   private int hash;
@@ -362,40 +302,53 @@ public StackTraceElement[] getCreationStackTrace() {
   // Note: isClosed flag is now packed into stateFlags (bit 2) for lock-free access
 
   /**
-   * Flag indicating whether memory was externally allocated (e.g., by Arena in tests). If true,
-   * close() should NOT release memory to segmentAllocator since it wasn't allocated by it.
+   * Flag indicating whether memory was externally allocated (e.g., by Arena in tests).
+   * If true, close() should NOT release memory to segmentAllocator since it wasn't allocated by it.
    */
   private final boolean externallyAllocatedMemory;
 
+  private MemorySegmentAllocator segmentAllocator =
+      OS.isWindows() ? WindowsMemorySegmentAllocator.getInstance() : LinuxMemorySegmentAllocator.getInstance();
+
+  /**
+   * Backing buffer from decompression (for zero-copy deserialization).
+   * When non-null, this buffer must be released on close().
+   */
+  private MemorySegment backingBuffer;
+
   /**
-   * Thread-local serialization buffer for compactFixedSlotsForCommit (avoids per-call allocation).
+   * Releaser to return backing buffer to allocator.
+   * Called on close() to return the decompression buffer to the allocator pool.
    */
-  private static final ThreadLocal COMPACT_BUFFER =
-      ThreadLocal.withInitial(() -> new MemorySegmentBytesOut(256));
+  private Runnable backingBufferReleaser;
 
-  private MemorySegmentAllocator segmentAllocator = OS.isWindows()
-      ? WindowsMemorySegmentAllocator.getInstance()
-      : LinuxMemorySegmentAllocator.getInstance();
+  // ==================== UNIFIED PAGE (LeanStore-style) ====================
 
   /**
-   * Backing buffer from decompression (for zero-copy deserialization). When non-null, this buffer
-   * contains the slotMemory as a slice and must be released on close(). This enables true zero-copy
-   * where the decompressed data becomes the page's storage directly.
+   * Slotted page MemorySegment (PostgreSQL/LeanStore-style: Header + Bitmap + Directory + Heap).
+   * Stores records in a heap with per-record offset tables,
+   * enabling O(1) field access via flyweight binding. The page layout is defined by
+   * {@link PageLayout}: header (32 B) + bitmap (128 B) + directory (8 KB) + heap.
+   *
+   * 
FlyweightNode records are serialized directly to the heap at createRecord time
+   * and bound for in-place mutation. Non-FlyweightNode records are serialized to the
+   * heap at commit time via processEntries.
    */
-  private MemorySegment backingBuffer;
+  private MemorySegment slottedPage;
 
   /**
-   * Releaser to return backing buffer to allocator. Called on close() to return the decompression
-   * buffer to the allocator pool.
+   * Actual capacity in bytes of the slottedPage segment.
+   * Tracked separately because slottedPage is reinterpreted to Long.MAX_VALUE
+   * to eliminate JIT bounds checks on MemorySegment get/set operations.
    */
-  private Runnable backingBufferReleaser;
+  private int slottedPageCapacity;
 
   /**
-   * Constructor which initializes a new {@link KeyValueLeafPage}. Memory is externally provided
-   * (e.g., by Arena in tests) and will NOT be released by close().
+   * Constructor which initializes a new {@link KeyValueLeafPage}.
+   * Memory is externally provided (e.g., by Arena in tests) and will NOT be released by close().
    *
-   * @param recordPageKey base key assigned to this node page
-   * @param indexType the index type
+   * @param recordPageKey  base key assigned to this node page
+   * @param indexType      the index type
    * @param resourceConfig the resource configuration
    */
   public KeyValueLeafPage(final @NonNegative long recordPageKey, final IndexType indexType,
@@ -407,11 +360,10 @@ public KeyValueLeafPage(final @NonNegative long recordPageKey, final IndexType i
   /**
    * Constructor which initializes a new {@link KeyValueLeafPage}.
    *
-   * @param recordPageKey base key assigned to this node page
-   * @param indexType the index type
-   * @param resourceConfig the resource configuration
-   * @param externallyAllocatedMemory if true, memory was allocated externally and won't be released
-   *        by close()
+   * @param recordPageKey              base key assigned to this node page
+   * @param indexType                  the index type
+   * @param resourceConfig             the resource configuration
+   * @param externallyAllocatedMemory  if true, memory was allocated externally and won't be released by close()
    */
   public KeyValueLeafPage(final @NonNegative long recordPageKey, final IndexType indexType,
       final ResourceConfiguration resourceConfig, final int revisionNumber, final MemorySegment slotMemory,
@@ -420,6 +372,7 @@ public KeyValueLeafPage(final @NonNegative long recordPageKey, final IndexType i
     // internal flow.
     assert resourceConfig != null : "The resource config must not be null!";
 
+    this.references = new ConcurrentHashMap<>();
     this.recordPageKey = recordPageKey;
     this.records = new DataRecord[Constants.NDP_NODE_COUNT];
     this.areDeweyIDsStored = resourceConfig.areDeweyIDsStored;
@@ -427,27 +380,29 @@ public KeyValueLeafPage(final @NonNegative long recordPageKey, final IndexType i
     this.resourceConfig = resourceConfig;
     this.recordPersister = resourceConfig.recordPersister;
     this.revision = revisionNumber;
-    this.slotOffsets = new int[Constants.NDP_NODE_COUNT];
-    this.deweyIdOffsets = new int[Constants.NDP_NODE_COUNT];
     this.stringValueOffsets = new int[Constants.NDP_NODE_COUNT];
-    this.slotBitmap = new long[BITMAP_WORDS]; // All bits initially 0 (no slots populated)
-    this.fixedFormatBitmap = new long[BITMAP_WORDS];
-    this.fixedSlotKinds = new byte[Constants.NDP_NODE_COUNT];
-    Arrays.fill(slotOffsets, -1);
-    Arrays.fill(deweyIdOffsets, -1);
+    this.slotBitmap = new long[BITMAP_WORDS];  // All bits initially 0 (no slots populated)
     Arrays.fill(stringValueOffsets, -1);
-    Arrays.fill(fixedSlotKinds, NO_FIXED_SLOT_KIND);
-    this.doResizeMemorySegmentsIfNeeded = true;
-    this.slotMemoryFreeSpaceStart = 0;
+
     this.lastSlotIndex = -1;
-    this.deweyIdMemoryFreeSpaceStart = 0;
     this.lastDeweyIdIndex = -1;
     this.stringValueMemoryFreeSpaceStart = 0;
     this.lastStringValueIndex = -1;
-    this.slotMemory = slotMemory;
-    this.deweyIdMemory = deweyIdMemory;
     this.externallyAllocatedMemory = externallyAllocatedMemory;
 
+    // Release passed-in legacy memory if not externally allocated (callers still pass it)
+    if (!externallyAllocatedMemory) {
+      if (slotMemory != null && slotMemory.byteSize() > 0) {
+        segmentAllocator.release(slotMemory);
+      }
+      if (deweyIdMemory != null && deweyIdMemory.byteSize() > 0) {
+        segmentAllocator.release(deweyIdMemory);
+      }
+    }
+
+    // Eagerly allocate slotted page — all pages use slotted page format
+    ensureSlottedPage();
+
     // Capture creation stack trace for leak tracing (only when diagnostics enabled)
     if (DEBUG_MEMORY_LEAKS) {
       this.creationStackTrace = Thread.currentThread().getStackTrace();
@@ -464,15 +419,15 @@ public KeyValueLeafPage(final @NonNegative long recordPageKey, final IndexType i
 
   /**
    * Constructor which reads deserialized data to the {@link KeyValueLeafPage} from the storage.
-   * Memory is allocated by the global allocator and WILL be released by close().
+   * The slotted page will be set by the caller via {@link #setSlottedPage(MemorySegment)}.
    *
-   * @param recordPageKey This is the base key of all contained nodes.
-   * @param revision The current revision.
-   * @param indexType The index type.
-   * @param resourceConfig The resource configuration.
+   * @param recordPageKey     This is the base key of all contained nodes.
+   * @param revision          The current revision.
+   * @param indexType         The index type.
+   * @param resourceConfig    The resource configuration.
    * @param areDeweyIDsStored Determines if DeweyIDs are stored or not.
-   * @param recordPersister Persistenter.
-   * @param references References to overflow pages.
+   * @param recordPersister   Persistenter.
+   * @param references        References to overflow pages.
    */
   public KeyValueLeafPage(final long recordPageKey, final int revision, final IndexType indexType,
       final ResourceConfiguration resourceConfig, final boolean areDeweyIDsStored,
@@ -484,137 +439,29 @@ public KeyValueLeafPage(final long recordPageKey, final int revision, final Inde
     this.resourceConfig = resourceConfig;
     this.areDeweyIDsStored = areDeweyIDsStored;
     this.recordPersister = recordPersister;
-    this.slotMemory = slotMemory;
-    this.deweyIdMemory = deweyIdMemory;
     this.references = references;
     this.records = new DataRecord[Constants.NDP_NODE_COUNT];
-    this.slotOffsets = new int[Constants.NDP_NODE_COUNT];
-    this.deweyIdOffsets = new int[Constants.NDP_NODE_COUNT];
     this.stringValueOffsets = new int[Constants.NDP_NODE_COUNT];
-    this.slotBitmap = new long[BITMAP_WORDS]; // Will be populated during deserialization
-    this.fixedFormatBitmap = new long[BITMAP_WORDS];
-    this.fixedSlotKinds = new byte[Constants.NDP_NODE_COUNT];
-    Arrays.fill(slotOffsets, -1);
-    Arrays.fill(deweyIdOffsets, -1);
+    this.slotBitmap = new long[BITMAP_WORDS];  // Will be populated from slotted page bitmap
     Arrays.fill(stringValueOffsets, -1);
-    Arrays.fill(fixedSlotKinds, NO_FIXED_SLOT_KIND);
     this.stringValueMemoryFreeSpaceStart = 0;
     this.lastStringValueIndex = -1;
-    this.doResizeMemorySegmentsIfNeeded = true;
-    this.slotMemoryFreeSpaceStart = 0;
+
     this.lastSlotIndex = lastSlotIndex;
     // Memory allocated by global allocator (e.g., during deserialization) - release on close()
     this.externallyAllocatedMemory = false;
 
-    if (areDeweyIDsStored) {
-      this.deweyIdMemoryFreeSpaceStart = 0;
-      this.lastDeweyIdIndex = lastDeweyIdIndex;
-    } else {
-      this.deweyIdMemoryFreeSpaceStart = 0;
-      this.lastDeweyIdIndex = -1;
-    }
-
-    // Capture creation stack trace for leak tracing (only when diagnostics enabled)
-    if (DEBUG_MEMORY_LEAKS) {
-      this.creationStackTrace = Thread.currentThread().getStackTrace();
-      PAGES_CREATED.incrementAndGet();
-      PAGES_BY_TYPE.computeIfAbsent(indexType, _ -> new java.util.concurrent.atomic.AtomicLong(0)).incrementAndGet();
-      ALL_LIVE_PAGES.add(this);
-      if (recordPageKey == 0) {
-        ALL_PAGE_0_INSTANCES.add(this);
-      }
-    } else {
-      this.creationStackTrace = null;
-    }
-  }
-
-  /**
-   * Zero-copy constructor - slotMemory IS a slice of the decompression buffer. The backing buffer is
-   * released when this page is closed.
-   * 
-   * 

-   * This constructor enables true zero-copy page deserialization where the decompressed data becomes
-   * the page's storage directly, eliminating the per-slot MemorySegment.copy() calls that were a
-   * major performance bottleneck.
-   *
-   * @param recordPageKey base key assigned to this node page
-   * @param revision the current revision
-   * @param indexType the index type
-   * @param resourceConfig the resource configuration
-   * @param slotOffsets pre-loaded slot offset array from serialized data
-   * @param slotMemory slice of decompression buffer (NOT copied)
-   * @param lastSlotIndex index of the last slot
-   * @param deweyIdOffsets pre-loaded dewey ID offset array (or null)
-   * @param deweyIdMemory slice for dewey IDs (or null)
-   * @param lastDeweyIdIndex index of the last dewey ID slot
-   * @param references overflow page references
-   * @param backingBuffer full decompression buffer (for lifecycle management)
-   * @param backingBufferReleaser returns buffer to allocator on close()
-   */
-  public KeyValueLeafPage(final long recordPageKey, final int revision, final IndexType indexType,
-      final ResourceConfiguration resourceConfig, final int[] slotOffsets, final MemorySegment slotMemory,
-      final int lastSlotIndex, final int[] deweyIdOffsets, final MemorySegment deweyIdMemory,
-      final int lastDeweyIdIndex, final Map references, final MemorySegment backingBuffer,
-      final Runnable backingBufferReleaser) {
-    this.recordPageKey = recordPageKey;
-    this.revision = revision;
-    this.indexType = indexType;
-    this.resourceConfig = resourceConfig;
-    this.recordPersister = resourceConfig.recordPersister;
-    this.areDeweyIDsStored = resourceConfig.areDeweyIDsStored;
-
-    // Zero-copy: use provided arrays and memory segments directly
-    this.slotOffsets = slotOffsets;
-    this.slotMemory = slotMemory;
-    this.lastSlotIndex = lastSlotIndex;
+    this.lastDeweyIdIndex = areDeweyIDsStored ? lastDeweyIdIndex : -1;
 
-    this.deweyIdOffsets = deweyIdOffsets != null
-        ? deweyIdOffsets
-        : new int[Constants.NDP_NODE_COUNT];
-    if (deweyIdOffsets == null) {
-      Arrays.fill(this.deweyIdOffsets, -1);
+    // Release dummy slotMemory passed by callers (e.g., PageKind allocates a 1-byte dummy)
+    if (slotMemory != null && slotMemory.byteSize() > 0) {
+      segmentAllocator.release(slotMemory);
     }
-    this.deweyIdMemory = deweyIdMemory;
-    this.lastDeweyIdIndex = lastDeweyIdIndex;
-
-    // String value memory (columnar storage) - not yet used in legacy constructor
-    this.stringValueOffsets = new int[Constants.NDP_NODE_COUNT];
-    Arrays.fill(this.stringValueOffsets, -1);
-    this.stringValueMemory = null;
-    this.lastStringValueIndex = -1;
-    this.stringValueMemoryFreeSpaceStart = 0;
-    this.fsstSymbolTable = null;
-
-    // Build bitmap from provided slotOffsets for O(k) iteration
-    this.slotBitmap = new long[BITMAP_WORDS];
-    this.fixedFormatBitmap = new long[BITMAP_WORDS];
-    this.fixedSlotKinds = new byte[Constants.NDP_NODE_COUNT];
-    Arrays.fill(this.fixedSlotKinds, NO_FIXED_SLOT_KIND);
-    for (int i = 0; i < slotOffsets.length; i++) {
-      if (slotOffsets[i] >= 0) {
-        slotBitmap[i >>> 6] |= (1L << (i & 63));
-      }
+    if (deweyIdMemory != null && deweyIdMemory.byteSize() > 0) {
+      segmentAllocator.release(deweyIdMemory);
     }
 
-    // Zero-copy: slotMemory is part of backingBuffer, track for release
-    this.backingBuffer = backingBuffer;
-    this.backingBufferReleaser = backingBufferReleaser;
-
-    // If we have a backing buffer, it owns the memory (zero-copy path)
-    // Otherwise, slotMemory was allocated separately and should be released via allocator
-    this.externallyAllocatedMemory = (backingBuffer != null);
-
-    this.references = references != null
-        ? references
-        : new ConcurrentHashMap<>();
-    this.records = new DataRecord[Constants.NDP_NODE_COUNT];
-
-    // Zero-copy pages are read-only snapshots, don't resize
-    this.doResizeMemorySegmentsIfNeeded = false;
-
-    // Free space tracking not needed for read-only zero-copy pages
-    this.slotMemoryFreeSpaceStart = 0;
-    this.deweyIdMemoryFreeSpaceStart = 0;
+    // Slotted page is set by caller via setSlottedPage() after construction.
 
     // Capture creation stack trace for leak tracing (only when diagnostics enabled)
     if (DEBUG_MEMORY_LEAKS) {
@@ -630,26 +477,7 @@ public KeyValueLeafPage(final long recordPageKey, final int revision, final Inde
     }
   }
 
-  // Update the last slot index after setting a slot.
-  private void updateLastSlotIndex(int slotNumber, boolean isSlotMemory) {
-    if (isSlotMemory) {
-      if (lastSlotIndex >= 0) {
-        if (slotOffsets[slotNumber] > slotOffsets[lastSlotIndex]) {
-          lastSlotIndex = slotNumber;
-        }
-      } else {
-        lastSlotIndex = slotNumber;
-      }
-    } else {
-      if (lastDeweyIdIndex >= 0) {
-        if (deweyIdOffsets[slotNumber] > deweyIdOffsets[lastDeweyIdIndex]) {
-          lastDeweyIdIndex = slotNumber;
-        }
-      } else {
-        lastDeweyIdIndex = slotNumber;
-      }
-    }
-  }
+
 
   @Override
   public int hashCode() {
@@ -673,135 +501,597 @@ public long getPageKey() {
   }
 
   @Override
-  public DataRecord getRecord(final int offset) {
-    if (offset < 0 || offset >= Constants.NDP_NODE_COUNT) {
-      throw new IllegalArgumentException(
-          "Record offset out of range [0, " + Constants.NDP_NODE_COUNT + "): " + offset);
-    }
+  public DataRecord getRecord(int offset) {
     return records[offset];
   }
 
-  /**
-   * Clear the cached record reference at the given offset.
-   * 

-   * Used after fixed-slot projection to prevent stale pooled object references from being returned by
-   * {@link #getRecord(int)}. Fixed-slot bytes are the authoritative source for fixed-format slots, so
-   * the cached record must be cleared to force re-materialization from those bytes on the next read.
-   *
-   * @param offset the slot offset to clear
-   * @throws IllegalArgumentException if offset is out of range [0, {@link Constants#NDP_NODE_COUNT})
-   */
-  public void clearRecord(final int offset) {
-    if (offset < 0 || offset >= Constants.NDP_NODE_COUNT) {
-      throw new IllegalArgumentException(
-          "Record offset out of range [0, " + Constants.NDP_NODE_COUNT + "): " + offset);
-    }
-    if (records[offset] != null) {
-      records[offset] = null;
-      inMemoryRecordCount--;
-    }
-  }
-
   @Override
   public void setRecord(@NonNull final DataRecord record) {
     addedReferences = false;
+    // Invalidate stale compressed cache — record mutation means cached bytes are outdated
+    compressedSegment = null;
     bytes = null;
     final var key = record.getNodeKey();
     final var offset = (int) (key - ((key >> Constants.NDP_NODE_COUNT_EXPONENT) << Constants.NDP_NODE_COUNT_EXPONENT));
-    if (records[offset] == null) {
-      inMemoryRecordCount++;
+
+    if (record instanceof FlyweightNode fn) {
+      if (fn.isWriteSingleton()) {
+        // Write singleton: serialize to heap, never store in records[] (aliasing risk).
+        if (slottedPage != null && fn.isBoundTo(slottedPage)) {
+          fn.setOwnerPage(this);
+          return;
+        }
+        ensureSlottedPage();
+        if (fn.isBound()) {
+          fn.unbind();
+        }
+        serializeToHeap(fn, key, offset);
+        return;
+      }
+      // Non-singleton FlyweightNode: unbind if bound, store in records[] for processEntries.
+      if (fn.isBound()) {
+        fn.unbind();
+      }
     }
+
     records[offset] = record;
   }
 
   /**
-   * Get bytes to serialize.
+   * Store a newly created record, serializing non-FlyweightNode data to the slotted page heap
+   * immediately. This is called from the createRecord path where node factories may reuse
+   * singleton objects. By serializing now and nulling records[], we preserve data before the
+   * singleton is reused for the next node creation.
    *
-   * @return bytes
+   * 
For FlyweightNode records, this delegates to {@link #setRecord} which handles heap
+   * serialization and binding. For non-FlyweightNode on slotted pages, the record is serialized
+   * to the heap and records[offset] is nulled — prepareRecordForModification will deserialize
+   * a fresh object from the heap when mutation is needed.
+   *
+   * @param record the newly created record
    */
-  public BytesOut getBytes() {
-    return bytes;
+  public void setNewRecord(@NonNull final DataRecord record) {
+    assert !(record instanceof FlyweightNode)
+        : "FlyweightNode must not go through setNewRecord — use serializeNewRecord";
+    addedReferences = false;
+    compressedSegment = null;
+    bytes = null;
+    final var key = record.getNodeKey();
+    final var offset = (int) (key - ((key >> Constants.NDP_NODE_COUNT_EXPONENT) << Constants.NDP_NODE_COUNT_EXPONENT));
+    records[offset] = record;
+  }
+
+  public void serializeNewRecord(final FlyweightNode fn, final long nodeKey, final int offset) {
+    addedReferences = false;
+    compressedSegment = null;
+    bytes = null;
+    serializeToHeap(fn, nodeKey, offset);
+    // Node stays bound after creation — next factory clearBinding() handles transition
   }
 
   /**
-   * Set bytes after serialization.
+   * Serialize a FlyweightNode to the slotted page heap, update directory/bitmap, and bind.
    *
-   * @param bytes bytes
+   * 
After this call the node is bound: getters/setters operate on page memory.
+   * processEntries will skip this record at commit time because {@code fn.isBound()} is true.
+   *
+   * @param fn      the flyweight node to serialize
+   * @param nodeKey the node's key
+   * @param offset  the slot index within the page (0-1023)
+   */
+  private void serializeToHeap(final FlyweightNode fn, final long nodeKey, final int offset) {
+    ensureSlottedPage();
+    // Get DeweyID bytes if stored (must capture BEFORE binding overwrites the node state)
+    final byte[] deweyIdBytes = areDeweyIDsStored ? fn.getDeweyIDAsBytes() : null;
+    final int deweyIdLen = deweyIdBytes != null ? deweyIdBytes.length : 0;
+
+    // Ensure heap has enough space for this record (value nodes can be large)
+    final int heapEnd = PageLayout.getHeapEnd(slottedPage);
+    final int estimatedSize = fn.estimateSerializedSize() + deweyIdLen
+        + (areDeweyIDsStored ? PageLayout.DEWEY_ID_TRAILER_SIZE : 0);
+    while (slottedPageCapacity - PageLayout.HEAP_START - heapEnd < estimatedSize) {
+      growSlottedPage();
+    }
+
+    // Write directly to heap at current end
+    final long absOffset = PageLayout.heapAbsoluteOffset(heapEnd);
+    final int recordBytes = fn.serializeToHeap(slottedPage, absOffset);
+
+    // When DeweyIDs are stored, append DeweyID data + 2-byte trailer
+    final int totalBytes;
+    if (areDeweyIDsStored) {
+      if (deweyIdLen > 0) {
+        MemorySegment.copy(deweyIdBytes, 0, slottedPage,
+            java.lang.foreign.ValueLayout.JAVA_BYTE, absOffset + recordBytes, deweyIdLen);
+      }
+      totalBytes = recordBytes + deweyIdLen + PageLayout.DEWEY_ID_TRAILER_SIZE;
+      PageLayout.writeDeweyIdTrailer(slottedPage, absOffset + totalBytes, deweyIdLen);
+    } else {
+      totalBytes = recordBytes;
+    }
+
+    // Update heap end and used counters
+    PageLayout.setHeapEnd(slottedPage, heapEnd + totalBytes);
+    PageLayout.setHeapUsed(slottedPage, PageLayout.getHeapUsed(slottedPage) + totalBytes);
+
+    // Update directory entry: [heapOffset][dataLength | nodeKindId]
+    PageLayout.setDirEntry(slottedPage, offset, heapEnd, totalBytes,
+        ((NodeKind) fn.getKind()).getId());
+
+    // Mark slot populated in bitmap and track last slot index (new slots only)
+    if (!PageLayout.isSlotPopulated(slottedPage, offset)) {
+      PageLayout.markSlotPopulated(slottedPage, offset);
+      PageLayout.setPopulatedCount(slottedPage,
+          PageLayout.getPopulatedCount(slottedPage) + 1);
+      lastSlotIndex = offset;
+    }
+
+    // Bind flyweight — all subsequent mutations go directly to page memory
+    fn.bind(slottedPage, absOffset, nodeKey, offset);
+    fn.setOwnerPage(this);
+  }
+
+  // ==================== DIRECT-TO-HEAP CREATION ====================
+
+  /**
+   * Prepare the heap for a direct record write. Ensures slotted page exists and has
+   * enough space. Returns the absolute offset where the caller should write.
+   *
+   * @param estimatedRecordSize upper bound on record bytes (from estimateSerializedSize)
+   * @param deweyIdLen          length of DeweyID bytes (0 if none)
+   * @return absolute byte offset in the slotted page MemorySegment to write at
    */
-  public void setBytes(BytesOut bytes) {
-    this.bytes = bytes;
+  public long prepareHeapForDirectWrite(final int estimatedRecordSize, final int deweyIdLen) {
+    ensureSlottedPage();
+    final int deweyOverhead = areDeweyIDsStored
+        ? deweyIdLen + PageLayout.DEWEY_ID_TRAILER_SIZE : 0;
+    final int totalEstimated = estimatedRecordSize + deweyOverhead;
+    int heapEnd = PageLayout.getHeapEnd(slottedPage);
+    while (slottedPageCapacity - PageLayout.HEAP_START - heapEnd < totalEstimated) {
+      growSlottedPage();
+      heapEnd = PageLayout.getHeapEnd(slottedPage);
+    }
+    return PageLayout.heapAbsoluteOffset(heapEnd);
   }
 
-  @Override
-  public DataRecord[] records() {
-    return records;
+  /**
+   * Complete a direct record write. Handles DeweyID trailer, directory entry, bitmap,
+   * heap counters, and flyweight binding. Called after the caller has written the record
+   * bytes via a static writeNewRecord method.
+   *
+   * @param nodeKindId   the node kind ID (e.g. NodeKind.OBJECT.getId())
+   * @param nodeKey      the node key
+   * @param slotOffset   the slot index (0-1023)
+   * @param recordBytes  number of bytes written by writeNewRecord
+   * @param deweyIdBytes DeweyID bytes (null if not stored)
+   */
+  public void completeDirectWrite(final int nodeKindId, final long nodeKey,
+      final int slotOffset, final int recordBytes, final byte[] deweyIdBytes) {
+    addedReferences = false;
+    compressedSegment = null;
+    bytes = null;
+
+    final int heapEnd = PageLayout.getHeapEnd(slottedPage);
+    final long absOffset = PageLayout.heapAbsoluteOffset(heapEnd);
+    final int deweyIdLen = deweyIdBytes != null ? deweyIdBytes.length : 0;
+
+    // DeweyID trailer
+    final int totalBytes;
+    if (areDeweyIDsStored) {
+      if (deweyIdLen > 0) {
+        MemorySegment.copy(deweyIdBytes, 0, slottedPage,
+            java.lang.foreign.ValueLayout.JAVA_BYTE, absOffset + recordBytes, deweyIdLen);
+      }
+      totalBytes = recordBytes + deweyIdLen + PageLayout.DEWEY_ID_TRAILER_SIZE;
+      PageLayout.writeDeweyIdTrailer(slottedPage, absOffset + totalBytes, deweyIdLen);
+    } else {
+      totalBytes = recordBytes;
+    }
+
+    // Update heap counters
+    PageLayout.setHeapEnd(slottedPage, heapEnd + totalBytes);
+    PageLayout.setHeapUsed(slottedPage, PageLayout.getHeapUsed(slottedPage) + totalBytes);
+
+    // Directory entry
+    PageLayout.setDirEntry(slottedPage, slotOffset, heapEnd, totalBytes, nodeKindId);
+
+    // Bitmap
+    if (!PageLayout.isSlotPopulated(slottedPage, slotOffset)) {
+      PageLayout.markSlotPopulated(slottedPage, slotOffset);
+      PageLayout.setPopulatedCount(slottedPage,
+          PageLayout.getPopulatedCount(slottedPage) + 1);
+      lastSlotIndex = slotOffset;
+    }
+    // NOTE: Caller is responsible for binding the flyweight and setting ownerPage.
+    // This eliminates interface dispatch (itable stubs) by letting the caller call
+    // bind()/setOwnerPage() on the concrete type directly.
   }
 
-  public int getInMemoryRecordCount() {
-    return inMemoryRecordCount;
+  /**
+   * Check whether DeweyIDs are stored on this page.
+   */
+  public boolean areDeweyIDsStored() {
+    return areDeweyIDsStored;
   }
 
-  public int getDemotionThreshold() {
-    return demotionThreshold;
+  /**
+   * Resize a record whose varint width changed. Appends new version at heap end,
+   * updates directory, re-binds, and sets ownerPage. Old space becomes dead
+   * (reclaimed on page compaction/rewrite at commit time).
+   *
+   * @param fn      the flyweight node (unbound, with updated Java fields)
+   * @param nodeKey the node's key
+   * @param offset  the slot index within the page (0-1023)
+   */
+  public void resizeRecord(final FlyweightNode fn, final long nodeKey, final int offset) {
+    compressedSegment = null;
+    bytes = null;
+    serializeToHeap(fn, nodeKey, offset);
   }
 
-  public boolean shouldDemoteRecords(IndexType currentIndexType) {
-    return currentIndexType == IndexType.DOCUMENT && inMemoryRecordCount >= demotionThreshold;
+  /**
+   * Resize a single field in a bound record by raw-copying unchanged fields and re-encoding
+   * only the changed field. Avoids the full unbind/re-serialize round-trip of {@link #resizeRecord}.
+   *
+   * 
Bump-allocates new heap space, calls {@link DeltaVarIntCodec#resizeField} to perform
+   * three-segment copy (before + changed + after), preserves DeweyID trailer, updates directory,
+   * and re-binds the flyweight to the new location.
+   *
+   * 
HFT note: Zero allocations. Uses {@link MemorySegment#copy} (AVX/SSE intrinsics).
+   * Cold path — only called on varint width change, which is rare (~5% of mutations).
+   *
+   * @param fn         the bound flyweight node (must be bound to this page's slotted page)
+   * @param nodeKey    the node's key
+   * @param slotIndex  the slot index within the page (0-1023)
+   * @param fieldIndex the index of the field to resize (0 to fieldCount-1)
+   * @param fieldCount total number of fields in this record type's offset table
+   * @param encoder    encodes the new field value at the target offset
+   */
+  public void resizeRecordField(final FlyweightNode fn, final long nodeKey, final int slotIndex,
+      final int fieldIndex, final int fieldCount, final DeltaVarIntCodec.FieldEncoder encoder) {
+    assert slottedPage != null : "resizeRecordField requires slotted page";
+    assert PageLayout.isSlotPopulated(slottedPage, slotIndex) : "slot not populated: " + slotIndex;
+
+    compressedSegment = null;
+    bytes = null;
+
+    // --- Read old record metadata from directory ---
+    final int oldHeapOffset = PageLayout.getDirHeapOffset(slottedPage, slotIndex);
+    final int oldTotalLen = PageLayout.getDirDataLength(slottedPage, slotIndex);
+    final int nodeKindId = PageLayout.getDirNodeKindId(slottedPage, slotIndex);
+    final long oldRecordBase = PageLayout.heapAbsoluteOffset(oldHeapOffset);
+
+    // --- Compute record-only length (excluding DeweyID trailer) ---
+    final int oldRecordOnlyLen = PageLayout.getRecordOnlyLength(slottedPage, slotIndex);
+
+    // DeweyID portion (between record data and trailer)
+    final int deweyIdLen;
+    final int deweyIdTrailerSize;
+    if (areDeweyIDsStored) {
+      deweyIdLen = PageLayout.getDeweyIdLength(slottedPage, slotIndex);
+      deweyIdTrailerSize = PageLayout.DEWEY_ID_TRAILER_SIZE;
+    } else {
+      deweyIdLen = 0;
+      deweyIdTrailerSize = 0;
+    }
+
+    // --- Estimate new size (old size ± max varint growth of 9 bytes) ---
+    final int maxNewRecordLen = oldRecordOnlyLen + 9;
+    final int maxNewTotalLen = maxNewRecordLen + deweyIdLen + deweyIdTrailerSize;
+
+    // --- Ensure heap capacity ---
+    final int heapEnd = PageLayout.getHeapEnd(slottedPage);
+    while (slottedPageCapacity - PageLayout.HEAP_START - heapEnd < maxNewTotalLen) {
+      growSlottedPage();
+    }
+
+    // --- Raw-copy resize: copy unchanged fields, re-encode changed field ---
+    final long newRecordBase = PageLayout.heapAbsoluteOffset(heapEnd);
+    final int newRecordLen = DeltaVarIntCodec.resizeField(
+        slottedPage, oldRecordBase, oldRecordOnlyLen,
+        fieldCount, fieldIndex,
+        slottedPage, newRecordBase,
+        encoder);
+
+    // --- Copy DeweyID data + trailer from old location ---
+    final int newTotalLen;
+    if (areDeweyIDsStored) {
+      // Copy DeweyID bytes (may be 0 length)
+      if (deweyIdLen > 0) {
+        final long oldDeweyStart = oldRecordBase + oldRecordOnlyLen;
+        final long newDeweyStart = newRecordBase + newRecordLen;
+        MemorySegment.copy(slottedPage, oldDeweyStart, slottedPage, newDeweyStart, deweyIdLen);
+      }
+      newTotalLen = newRecordLen + deweyIdLen + deweyIdTrailerSize;
+      PageLayout.writeDeweyIdTrailer(slottedPage, newRecordBase + newTotalLen, deweyIdLen);
+    } else {
+      newTotalLen = newRecordLen;
+    }
+
+    // --- Update heap counters (old space becomes dead) ---
+    PageLayout.setHeapEnd(slottedPage, heapEnd + newTotalLen);
+    // heapUsed: subtract old, add new (net change = newTotalLen - oldTotalLen)
+    PageLayout.setHeapUsed(slottedPage,
+        PageLayout.getHeapUsed(slottedPage) + newTotalLen - oldTotalLen);
+
+    // --- Update directory entry ---
+    PageLayout.setDirEntry(slottedPage, slotIndex, heapEnd, newTotalLen, nodeKindId);
+
+    // --- Re-bind flyweight to new location ---
+    fn.bind(slottedPage, newRecordBase, nodeKey, slotIndex);
+    fn.setOwnerPage(this);
   }
 
-  public void onRecordRematerialized() {
-    rematerializedRecordsSinceLastDemotion++;
-    if (rematerializedRecordsSinceLastDemotion > demotionThreshold * 2) {
-      demotionThreshold = Math.min(MAX_DEMOTION_THRESHOLD, demotionThreshold + DEMOTION_STEP);
-      rematerializedRecordsSinceLastDemotion = 0;
+  /**
+   * Zero-copy raw slot bytes from source page to this page's heap.
+   * Copies the record body + DeweyID trailer verbatim, avoiding deserialize-serialize round-trip.
+   *
+   * @param sourcePage the source page to copy from
+   * @param slotIndex  the slot index to copy
+   */
+  public void copySlotFromPage(final KeyValueLeafPage sourcePage, final int slotIndex) {
+    final MemorySegment srcPage = sourcePage.getSlottedPage();
+    if (srcPage == null || !PageLayout.isSlotPopulated(srcPage, slotIndex)) {
+      return;
     }
+    ensureSlottedPage();
+
+    // Read source slot metadata
+    final int srcHeapOffset = PageLayout.getDirHeapOffset(srcPage, slotIndex);
+    final int srcTotalLen = PageLayout.getDirDataLength(srcPage, slotIndex);
+    final int srcNodeKindId = PageLayout.getDirNodeKindId(srcPage, slotIndex);
+
+    // Ensure destination has enough space
+    final int heapEnd = PageLayout.getHeapEnd(slottedPage);
+    while (slottedPageCapacity - PageLayout.HEAP_START - heapEnd < srcTotalLen) {
+      growSlottedPage();
+    }
+
+    // Copy raw bytes (record body + DeweyID trailer) from source to destination heap
+    final long srcAbs = PageLayout.heapAbsoluteOffset(srcHeapOffset);
+    final long dstAbs = PageLayout.heapAbsoluteOffset(heapEnd);
+    MemorySegment.copy(srcPage, srcAbs, slottedPage, dstAbs, srcTotalLen);
+
+    // Update destination heap end and used counters
+    PageLayout.setHeapEnd(slottedPage, heapEnd + srcTotalLen);
+    PageLayout.setHeapUsed(slottedPage, PageLayout.getHeapUsed(slottedPage) + srcTotalLen);
+
+    // Update destination directory entry
+    PageLayout.setDirEntry(slottedPage, slotIndex, heapEnd, srcTotalLen, srcNodeKindId);
+
+    // Mark slot populated in bitmap
+    if (!PageLayout.isSlotPopulated(slottedPage, slotIndex)) {
+      PageLayout.markSlotPopulated(slottedPage, slotIndex);
+      PageLayout.setPopulatedCount(slottedPage, PageLayout.getPopulatedCount(slottedPage) + 1);
+      lastSlotIndex = slotIndex;
+    }
+
+    // Invalidate compressed cache
+    compressedSegment = null;
+    bytes = null;
+    addedReferences = false;
   }
 
-  public int demoteRecordsToSlots(ResourceConfiguration config, MemorySegmentBytesOut reusableOut) {
-    if (inMemoryRecordCount <= MIN_DEMOTION_THRESHOLD) {
-      return 0;
+  /**
+   * Check if the slotted page has a populated slot for the given record key.
+   *
+   * @param recordKey the record key
+   * @return true if the slot is populated on the slotted page
+   */
+  public boolean hasSlottedPageSlot(final long recordKey) {
+    if (slottedPage == null) {
+      return false;
     }
+    final int offset = (int) (recordKey - ((recordKey >> Constants.NDP_NODE_COUNT_EXPONENT)
+        << Constants.NDP_NODE_COUNT_EXPONENT));
+    return PageLayout.isSlotPopulated(slottedPage, offset);
+  }
 
-    final RecordSerializer serializer = config.recordPersister;
-    int demoted = 0;
+  /**
+   * Allocate and initialize the slotted page if not yet present.
+   */
+  public void ensureSlottedPage() {
+    if (slottedPage != null) {
+      return;
+    }
+    final MemorySegment allocated = segmentAllocator.allocate(PageLayout.INITIAL_PAGE_SIZE);
+    slottedPageCapacity = (int) allocated.byteSize();
+    PageLayout.initializePage(allocated, recordPageKey, revision, indexType.getID(), areDeweyIDsStored);
+    slottedPage = allocated.reinterpret(Long.MAX_VALUE);
+  }
 
-    for (int i = 0; i < records.length && inMemoryRecordCount > MIN_DEMOTION_THRESHOLD; i++) {
-      final DataRecord record = records[i];
-      if (record == null) {
-        continue;
-      }
+  /**
+   * Grow the slotted page by doubling its size.
+   * Copies all existing data (header + bitmap + directory + heap) to the new segment.
+   */
+  private void growSlottedPage() {
+    final int currentSize = slottedPageCapacity;
+    final int newSize = currentSize * 2;
+    final MemorySegment grown = segmentAllocator.allocate(newSize);
+    // Copy all existing data
+    MemorySegment.copy(slottedPage, 0, grown, 0, currentSize);
+    // Release old segment (reinterpret back to actual size for allocator)
+    segmentAllocator.release(slottedPage.reinterpret(currentSize));
+    slottedPageCapacity = (int) grown.byteSize();
+    slottedPage = grown.reinterpret(Long.MAX_VALUE);
+    // No rebind needed: the caller (serializeToHeap) will rebind the active flyweight.
+  }
 
-      reusableOut.clear();
-      serializer.serialize(reusableOut, record, config);
-      final MemorySegment segment = reusableOut.getDestination();
+  /**
+   * Write raw slot data to the slotted page heap.
+   * Used by setSlot() and addReferences() when slottedPage is active.
+   * Data is stored without a length prefix — the directory entry holds the length.
+   *
+   * @param data       the raw slot data to store
+   * @param slotNumber the slot index (0-1023)
+   * @param nodeKindId the node kind ID (0 for legacy format, >0 for flyweight)
+   */
+  private void setSlotToHeap(final MemorySegment data, final int slotNumber, final int nodeKindId) {
+    final int recordSize = (int) data.byteSize();
+    if (recordSize <= 0) {
+      return;
+    }
 
-      if (segment.byteSize() > PageConstants.MAX_RECORD_SIZE) {
-        continue;
+    // Total allocation includes DeweyID trailer when DeweyIDs are stored
+    final int totalSize = areDeweyIDsStored
+        ? recordSize + PageLayout.DEWEY_ID_TRAILER_SIZE
+        : recordSize;
+
+    // Ensure heap has enough space
+    int heapEnd = PageLayout.getHeapEnd(slottedPage);
+    int remaining = slottedPageCapacity - PageLayout.HEAP_START - heapEnd;
+    if (remaining < totalSize) {
+      while (slottedPageCapacity - PageLayout.HEAP_START - heapEnd < totalSize) {
+        growSlottedPage();
       }
+      heapEnd = PageLayout.getHeapEnd(slottedPage);
+    }
 
-      setSlot(segment, i);
-      markSlotAsCompactFormat(i);
+    // Bump-allocate and copy record data to heap
+    final long absOffset = PageLayout.heapAbsoluteOffset(heapEnd);
+    MemorySegment.copy(data, 0, slottedPage, absOffset, recordSize);
 
-      if (config.areDeweyIDsStored && record.getNodeKey() != 0) {
-        final byte[] deweyBytes = record.getDeweyIDAsBytes();
-        if (deweyBytes != null) {
-          setDeweyId(deweyBytes, i);
-        }
+    // Append DeweyID trailer (initially 0 = no DeweyID yet)
+    if (areDeweyIDsStored) {
+      PageLayout.writeDeweyIdTrailer(slottedPage, absOffset + totalSize, 0);
+    }
+
+    // Update heap end and used counters
+    PageLayout.setHeapEnd(slottedPage, heapEnd + totalSize);
+    PageLayout.setHeapUsed(slottedPage, PageLayout.getHeapUsed(slottedPage) + totalSize);
+
+    // Update directory entry with the provided nodeKindId
+    PageLayout.setDirEntry(slottedPage, slotNumber, heapEnd, totalSize, nodeKindId);
+
+    // Mark slot populated in bitmap and track last slot index (new slots only)
+    if (!PageLayout.isSlotPopulated(slottedPage, slotNumber)) {
+      PageLayout.markSlotPopulated(slottedPage, slotNumber);
+      PageLayout.setPopulatedCount(slottedPage,
+          PageLayout.getPopulatedCount(slottedPage) + 1);
+      lastSlotIndex = slotNumber;
+    }
+  }
+
+  /**
+   * Write raw slot data from a source segment at a given offset to the slotted page heap.
+   * Zero-copy variant for direct page deserialization.
+   *
+   * @param source       the source MemorySegment containing the data
+   * @param sourceOffset byte offset within source where data starts
+   * @param dataSize     number of bytes to copy
+   * @param slotNumber   the slot index (0-1023)
+   * @param nodeKindId   the node kind ID (0 for legacy format, 24-43 for flyweight)
+   */
+  void setSlotToHeapDirect(final MemorySegment source, final long sourceOffset,
+      final int dataSize, final int slotNumber, final int nodeKindId) {
+    if (dataSize <= 0) {
+      return;
+    }
+
+    // Ensure heap has enough space
+    int heapEnd = PageLayout.getHeapEnd(slottedPage);
+    final int remaining = slottedPageCapacity - PageLayout.HEAP_START - heapEnd;
+    if (remaining < dataSize) {
+      while (slottedPageCapacity - PageLayout.HEAP_START - heapEnd < dataSize) {
+        growSlottedPage();
       }
+      heapEnd = PageLayout.getHeapEnd(slottedPage);
+    }
 
-      records[i] = null;
-      inMemoryRecordCount--;
-      demoted++;
+    // Bump-allocate and copy data to heap
+    final long absOffset = PageLayout.heapAbsoluteOffset(heapEnd);
+    MemorySegment.copy(source, sourceOffset, slottedPage, absOffset, dataSize);
+
+    // Update heap end and used counters
+    PageLayout.setHeapEnd(slottedPage, heapEnd + dataSize);
+    PageLayout.setHeapUsed(slottedPage, PageLayout.getHeapUsed(slottedPage) + dataSize);
+
+    // Update directory entry
+    PageLayout.setDirEntry(slottedPage, slotNumber, heapEnd, dataSize, nodeKindId);
+
+    // Mark slot populated in bitmap
+    if (!PageLayout.isSlotPopulated(slottedPage, slotNumber)) {
+      PageLayout.markSlotPopulated(slottedPage, slotNumber);
+      PageLayout.setPopulatedCount(slottedPage,
+          PageLayout.getPopulatedCount(slottedPage) + 1);
     }
+  }
+
+  /**
+   * Get bytes to serialize.
+   *
+   * @return bytes
+   */
+  public BytesOut getBytes() {
+    return bytes;
+  }
+
+  /**
+   * Set bytes after serialization (legacy byte[] path).
+   *
+   * @param bytes bytes
+   */
+  public void setBytes(final BytesOut bytes) {
+    this.bytes = bytes;
+    this.compressedSegment = null;
+  }
+
+  /**
+   * Get the compressed page data as a MemorySegment (zero-copy path).
+   *
+   * @return the compressed segment, or null if not set
+   */
+  public MemorySegment getCompressedSegment() {
+    return compressedSegment;
+  }
 
-    if (demoted > 0) {
-      if (rematerializedRecordsSinceLastDemotion < demoted / 4) {
-        demotionThreshold = Math.max(MIN_DEMOTION_THRESHOLD, demotionThreshold - DEMOTION_STEP);
+  /**
+   * Set compressed page data as a MemorySegment (zero-copy path).
+   * Clears the legacy bytes cache.
+   *
+   * @param segment the compressed segment (Arena.ofAuto()-managed)
+   */
+  public void setCompressedSegment(final MemorySegment segment) {
+    this.compressedSegment = segment;
+    this.bytes = null;
+  }
+
+  /**
+   * Release node object references to allow GC to reclaim them.
+   * 

+   * MUST only be called after {@code addReferences()} has serialized all records into
+   * {@code slotMemory} and the compressed form is cached via {@code setCompressedSegment()}
+   * or {@code setBytes()}. After this call, individual records can still be reconstructed
+   * on demand from {@code slotMemory} via {@code getSlot(offset)} in
+   * {@link io.sirix.access.trx.page.NodeStorageEngineReader#getValue}.
+   */
+  public void clearRecordsForGC() {
+    // Unbind flyweight nodes BEFORE clearing — cursors may still hold references.
+    // Unbinding materializes all fields from page memory (still valid at this point)
+    // into Java primitives, so reads after page release use correct field values.
+    if (slottedPage != null) {
+      for (final DataRecord record : records) {
+        if (record instanceof FlyweightNode fn && fn.isBound()) {
+          fn.unbind();
+        }
       }
-      rematerializedRecordsSinceLastDemotion = 0;
     }
+    Arrays.fill(records, null);
+  }
 
-    return demoted;
+  /**
+   * Check whether all non-null records have been serialized to slotMemory.
+   *
+   * @return {@code true} if {@link #addReferences} has been called and no subsequent
+   *         {@link #setRecord} has invalidated the serialized state
+   */
+  public boolean isAddedReferences() {
+    return addedReferences;
+  }
+
+  @Override
+  public DataRecord[] records() {
+    return records;
   }
 
   public byte[] getHashCode() {
@@ -819,12 +1109,12 @@ public > I values() {
   }
 
   public Map getReferencesMap() {
-    return references != null ? references : Map.of();
+    return references;
   }
 
   /**
-   * Set reference to the complete page for lazy slot copying at commit time. Used by DIFFERENTIAL,
-   * INCREMENTAL (full-dump), and SLIDING_SNAPSHOT versioning.
+   * Set reference to the complete page for lazy slot copying at commit time.
+   * Used by DIFFERENTIAL, INCREMENTAL (full-dump), and SLIDING_SNAPSHOT versioning.
    *
    * @param completePage the complete page to copy slots from
    */
@@ -842,8 +1132,8 @@ public KeyValueLeafPage getCompletePageRef() {
   }
 
   /**
-   * Mark a slot for preservation during lazy copy at commit time. At addReferences(), if this slot
-   * has records[i] == null, it will be copied from completePageRef.
+   * Mark a slot for preservation during lazy copy at commit time.
+   * At addReferences(), if this slot has records[i] == null, it will be copied from completePageRef.
    *
    * @param slotNumber the slot number to mark for preservation (0 to Constants.NDP_NODE_COUNT-1)
    */
@@ -861,7 +1151,8 @@ public void markSlotForPreservation(int slotNumber) {
    * @return true if the slot needs preservation
    */
   public boolean isSlotMarkedForPreservation(int slotNumber) {
-    return preservationBitmap != null && (preservationBitmap[slotNumber >>> 6] & (1L << (slotNumber & 63))) != 0;
+    return preservationBitmap != null && 
+           (preservationBitmap[slotNumber >>> 6] & (1L << (slotNumber & 63))) != 0;
   }
 
   /**
@@ -882,273 +1173,61 @@ public boolean hasPreservationSlots() {
     return preservationBitmap != null;
   }
 
-  private static final int ALIGNMENT = 4; // 4-byte alignment for int
-
-  private static int alignOffset(int offset) {
-    return (offset + ALIGNMENT - 1) & -ALIGNMENT;
-  }
 
   @Override
   public void setSlot(byte[] recordData, int slotNumber) {
-    setData(recordData, slotNumber, slotOffsets, slotMemory);
-  }
-
-  public void setSlotMemory(MemorySegment slotMemory) {
-    this.slotMemory = slotMemory;
-  }
-
-  public void setDeweyIdMemory(MemorySegment deweyIdMemory) {
-    this.deweyIdMemory = deweyIdMemory;
+    ensureSlottedPage();
+    setSlotToHeap(MemorySegment.ofArray(recordData), slotNumber, 0);
   }
 
   @Override
   public void setSlot(MemorySegment data, int slotNumber) {
-    setData(data, slotNumber, slotOffsets, slotMemory);
+    ensureSlottedPage();
+    setSlotToHeap(data, slotNumber, 0);
   }
 
   /**
-   * Set slot data by copying directly from a source MemorySegment. This is the zero-copy path that
-   * avoids intermediate byte[] allocations during deserialization.
+   * Set slot data with an explicit nodeKindId. Used during page combining
+   * to preserve the flyweight format indicator from the source page.
    *
-   * 

-   * Memory layout written to slotMemory: [length (4 bytes)][data (dataSize bytes)]
-   * 

+   * @param data       the raw slot data to store
+   * @param slotNumber the slot index (0-1023)
+   * @param nodeKindId the node kind ID (0 for legacy, >0 for flyweight)
+   */
+  public void setSlotWithNodeKind(final MemorySegment data, final int slotNumber, final int nodeKindId) {
+    ensureSlottedPage();
+    setSlotToHeap(data, slotNumber, nodeKindId);
+  }
+
+  /**
+   * Get the nodeKindId for a slot from the slotted page directory.
+   * Returns 0 if the slotted page is not initialized or the slot is unpopulated.
    *
-   * 

-   * This method is optimized for the page deserialization hot path where we can copy directly from
-   * the decompressed page data segment to the target slot memory without creating temporary byte[]
-   * arrays.
-   * 

+   * @param slotNumber the slot index (0-1023)
+   * @return the nodeKindId (>0 for flyweight format, 0 for legacy)
+   */
+  public int getSlotNodeKindId(final int slotNumber) {
+    if (slottedPage == null || !PageLayout.isSlotPopulated(slottedPage, slotNumber)) {
+      return 0;
+    }
+    return PageLayout.getDirNodeKindId(slottedPage, slotNumber);
+  }
+
+  /**
+   * Set slot data by copying directly from a source MemorySegment.
+   * Zero-copy path for page deserialization.
    *
    * @param source the source MemorySegment containing the data
    * @param sourceOffset the byte offset within source where data starts
    * @param dataSize the number of bytes to copy (must be > 0)
    * @param slotNumber the slot number (0 to Constants.NDP_NODE_COUNT-1)
-   * @throws IllegalArgumentException if dataSize <= 0 or slotNumber out of range
-   * @throws IndexOutOfBoundsException if source bounds would be exceeded
    */
   public void setSlotDirect(MemorySegment source, long sourceOffset, int dataSize, int slotNumber) {
-    // Validate inputs
-    if (dataSize <= 0) {
-      throw new IllegalArgumentException("dataSize must be positive: " + dataSize);
-    }
-    if (slotNumber < 0 || slotNumber >= Constants.NDP_NODE_COUNT) {
-      throw new IllegalArgumentException("slotNumber out of range: " + slotNumber);
-    }
-    if (sourceOffset < 0 || sourceOffset + dataSize > source.byteSize()) {
-      throw new IndexOutOfBoundsException(String.format("Source bounds exceeded: offset=%d, size=%d, segmentSize=%d",
-          sourceOffset, dataSize, source.byteSize()));
-    }
-
-    int requiredSize = INT_SIZE + dataSize; // 4 bytes for length prefix + actual data
-    int currentOffset = slotOffsets[slotNumber];
-    int sizeDelta = 0;
-
-    // Check if resizing is needed
-    if (!hasEnoughSpace(slotOffsets, slotMemory, requiredSize)) {
-      int newSize = Math.max((int) slotMemory.byteSize() * 2, (int) slotMemory.byteSize() + requiredSize);
-      slotMemory = resizeMemorySegment(slotMemory, newSize, slotOffsets, true);
-    }
-
-    if (currentOffset >= 0) {
-      // Existing slot - check if size changed
-      int alignedOffset = alignOffset(currentOffset);
-      int currentSize = INT_SIZE + slotMemory.get(ValueLayout.JAVA_INT, alignedOffset);
-
-      if (currentSize == requiredSize) {
-        // Same size - overwrite in place (fast path)
-        slotMemory.set(ValueLayout.JAVA_INT, alignedOffset, dataSize);
-        MemorySegment.copy(source, sourceOffset, slotMemory, alignedOffset + INT_SIZE, dataSize);
-        return;
-      }
-      sizeDelta = requiredSize - currentSize;
-      slotOffsets[slotNumber] = alignOffset(currentOffset);
-    } else {
-      // New slot - find free space
-      currentOffset = findFreeSpaceForSlots(requiredSize, true);
-      slotOffsets[slotNumber] = alignOffset(currentOffset);
-      updateLastSlotIndex(slotNumber, true);
-      // Update bitmap for newly populated slot
-      slotBitmap[slotNumber >>> 6] |= (1L << (slotNumber & 63));
-    }
-
-    // Perform shifting if size changed for existing slot
-    if (sizeDelta != 0) {
-      shiftSlotMemory(slotNumber, sizeDelta, slotOffsets, slotMemory);
-    }
-
-    // Write length prefix
-    int alignedOffset = alignOffset(currentOffset);
-    slotMemory.set(ValueLayout.JAVA_INT, alignedOffset, dataSize);
-
-    // Verify the write
-    int verifiedSize = slotMemory.get(ValueLayout.JAVA_INT, alignedOffset);
-    if (verifiedSize != dataSize) {
-      throw new IllegalStateException(
-          String.format("Slot size verification failed: expected=%d, actual=%d (slot: %d, offset: %d)", dataSize,
-              verifiedSize, slotNumber, alignedOffset));
-    }
-
-    // Copy data directly from source segment to slot memory (ZERO-COPY from caller's perspective!)
-    MemorySegment.copy(source, sourceOffset, slotMemory, alignedOffset + INT_SIZE, dataSize);
-
-    // Update free space tracking
-    updateFreeSpaceStart(slotOffsets, slotMemory, true);
-  }
-
-  private MemorySegment setData(Object data, int slotNumber, int[] offsets, MemorySegment memory) {
-    if (data == null) {
-      return null;
-    }
-
-    int dataSize;
-
-    if (data instanceof MemorySegment) {
-      dataSize = (int) ((MemorySegment) data).byteSize();
-
-      if (dataSize == 0) {
-        return null;
-      }
-    } else if (data instanceof byte[]) {
-      dataSize = ((byte[]) data).length;
-
-      if (dataSize == 0) {
-        return null;
-      }
-    } else {
-      throw new IllegalArgumentException("Data must be either a MemorySegment or a byte array.");
-    }
-
-    int requiredSize = INT_SIZE + dataSize;
-    int currentOffset = offsets[slotNumber];
-
-    int sizeDelta = 0;
-
-    boolean resized = false;
-    boolean isSlotMemory = memory == slotMemory;
-
-    // Check if resizing is needed.
-    if (!hasEnoughSpace(offsets, memory, requiredSize + sizeDelta)) {
-      // Resize the memory segment.
-      int newSize = Math.max(((int) memory.byteSize()) * 2, ((int) memory.byteSize()) + requiredSize + sizeDelta);
-
-      memory = resizeMemorySegment(memory, newSize, offsets, isSlotMemory);
-
-      resized = true;
-    }
-
-    if (currentOffset >= 0) {
-      // Existing slot, check if there's enough space to accommodate the new data.
-      long alignedOffset = alignOffset(currentOffset);
-      int currentSize = INT_SIZE + memory.get(ValueLayout.JAVA_INT, alignedOffset);
-
-      if (currentSize == requiredSize) {
-        // If the size is the same, update it directly.
-        memory.set(ValueLayout.JAVA_INT, alignedOffset, dataSize);
-        if (data instanceof MemorySegment) {
-          MemorySegment.copy((MemorySegment) data, 0, memory, alignedOffset + INT_SIZE, dataSize);
-        } else {
-          MemorySegment.copy(data, 0, memory, ValueLayout.JAVA_BYTE, alignedOffset + INT_SIZE, dataSize);
-        }
-
-        return null; // No resizing needed
-      } else {
-        // Calculate sizeDelta based on whether the new data is larger or smaller.
-        sizeDelta = requiredSize - currentSize;
-      }
-
-      offsets[slotNumber] = alignOffset(currentOffset);
-    } else {
-      // If the slot is empty, determine where to place the new data.
-      currentOffset = findFreeSpaceForSlots(requiredSize, isSlotMemory);
-      offsets[slotNumber] = alignOffset(currentOffset);
-      updateLastSlotIndex(slotNumber, isSlotMemory);
-      // Update bitmap for newly populated slot (slot memory only)
-      if (isSlotMemory) {
-        slotBitmap[slotNumber >>> 6] |= (1L << (slotNumber & 63));
-      }
-    }
-
-    // Perform any necessary shifting.
-    if (sizeDelta != 0) {
-      shiftSlotMemory(slotNumber, sizeDelta, offsets, memory);
-    }
-
-    // Write the new data into the slot.
-    int alignedOffset = alignOffset(currentOffset);
-    memory.set(ValueLayout.JAVA_INT, alignedOffset, dataSize);
-
-    // Verify the write
-    int verifiedSize = memory.get(ValueLayout.JAVA_INT, alignedOffset);
-    if (verifiedSize <= 0) {
-      throw new IllegalStateException(String.format("Invalid slot size written: %d (slot: %d, offset: %d)",
-          verifiedSize, slotNumber, alignedOffset));
-    }
-
-
-    if (data instanceof MemorySegment) {
-      MemorySegment.copy((MemorySegment) data, 0, memory, alignedOffset + INT_SIZE, dataSize);
-    } else {
-      MemorySegment.copy(data, 0, memory, ValueLayout.JAVA_BYTE, alignedOffset + INT_SIZE, dataSize);
-    }
-
-    // Update slotMemoryFreeSpaceStart after adding the slot.
-    updateFreeSpaceStart(offsets, memory, isSlotMemory);
-
-    return resized
-        ? memory
-        : null;
-  }
-
-  private void updateFreeSpaceStart(int[] offsets, MemorySegment memory, boolean isSlotMemory) {
-    int freeSpaceStart = (int) memory.byteSize() - getAvailableSpace(offsets, memory);
-    if (isSlotMemory) {
-      slotMemoryFreeSpaceStart = freeSpaceStart;
-    } else {
-      deweyIdMemoryFreeSpaceStart = freeSpaceStart;
-    }
+    ensureSlottedPage();
+    setSlotToHeapDirect(source, sourceOffset, dataSize, slotNumber, 0);
   }
 
-  boolean hasEnoughSpace(int[] offsets, MemorySegment memory, int requiredDataSize) {
-    if (!doResizeMemorySegmentsIfNeeded) {
-      return true;
-    }
-
-    // Check if the available space can accommodate the new slot.
-    return getAvailableSpace(offsets, memory) >= requiredDataSize;
-  }
-
-  int getAvailableSpace(int[] offsets, MemorySegment memory) {
-    boolean isSlotMemory = memory == slotMemory;
-
-    int lastSlotIndex = getLastIndex(isSlotMemory);
 
-    // If no slots are set yet, start from the beginning of the memory.
-    int lastOffset = (lastSlotIndex >= 0)
-        ? offsets[lastSlotIndex]
-        : 0;
-
-    // Align the last offset
-    int alignedLastOffset = alignOffset(lastOffset);
-
-    // If there is a valid last slot, add its size to the aligned offset.
-    int lastSlotSize = 0;
-    if (lastSlotIndex >= 0) {
-      // The size of the last slot (including the size of the integer that stores the data length)
-      lastSlotSize = INT_SIZE + memory.get(ValueLayout.JAVA_INT, alignedLastOffset);
-    }
-
-    // Calculate available space from the end of the last slot to the end of memory.
-    return (int) memory.byteSize() - alignOffset(alignedLastOffset + lastSlotSize);
-  }
-
-  int getLastIndex(boolean isSlotMemory) {
-    if (isSlotMemory) {
-      return lastSlotIndex;
-    } else {
-      return lastDeweyIdIndex;
-    }
-  }
 
   public int getLastSlotIndex() {
     return lastSlotIndex;
@@ -1158,110 +1237,52 @@ public int getLastDeweyIdIndex() {
     return lastDeweyIdIndex;
   }
 
-  /**
-   * Get the slot offsets array for zero-copy serialization. Each element is the byte offset within
-   * slotMemory where the slot's data begins, or -1 if the slot is empty.
-   * 
-   * @return the slot offsets array (do not modify)
-   */
-  public int[] getSlotOffsets() {
-    return slotOffsets;
-  }
 
   /**
-   * Get the slot bitmap for O(k) iteration over populated slots. Bit i is set (1) iff slot i is
-   * populated (slotOffsets[i] >= 0).
+   * Get the slot bitmap for O(k) iteration over populated slots.
+   * Bit i is set (1) iff slot i is populated (slotOffsets[i] >= 0).
    * 
    * @return the slot bitmap array (16 longs = 1024 bits, do not modify)
    */
   public long[] getSlotBitmap() {
+    if (slottedPage != null) {
+      // Materialize slotted page bitmap into the Java array for VersioningType compatibility
+      PageLayout.copyBitmapTo(slottedPage, slotBitmap);
+    }
     return slotBitmap;
   }
 
   /**
-   * Returns bitmap of slots stored in fixed in-memory layout.
-   */
-  public long[] getFixedFormatBitmap() {
-    return fixedFormatBitmap;
-  }
-
-  /**
-   * Check if a specific slot is populated using the bitmap. This is O(1) and avoids memory access to
-   * slotOffsets.
+   * Check if a specific slot is populated using the bitmap.
+   * This is O(1) and avoids memory access to slotOffsets.
    * 
    * @param slotNumber the slot index (0-1023)
    * @return true if the slot is populated
    */
   public boolean hasSlot(int slotNumber) {
-    return (slotBitmap[slotNumber >>> 6] & (1L << (slotNumber & 63))) != 0;
-  }
-
-  /**
-   * Returns {@code true} if slot data is in fixed in-memory layout.
-   */
-  public boolean isFixedSlotFormat(int slotNumber) {
-    return (fixedFormatBitmap[slotNumber >>> 6] & (1L << (slotNumber & 63))) != 0;
-  }
-
-  /**
-   * Returns node kind for a fixed-format slot, or {@code null} if the slot is compact or fixed
-   * metadata is unavailable.
-   */
-  public NodeKind getFixedSlotNodeKind(final int slotNumber) {
-    if (!isFixedSlotFormat(slotNumber)) {
-      return null;
+    if (slottedPage != null) {
+      return PageLayout.isSlotPopulated(slottedPage, slotNumber);
     }
-    final byte kindId = fixedSlotKinds[slotNumber];
-    if (kindId == NO_FIXED_SLOT_KIND) {
-      return null;
-    }
-    return NodeKind.getKind(kindId);
-  }
-
-  /**
-   * Mark slot as fixed-layout in-memory representation.
-   */
-  public void markSlotAsFixedFormat(final int slotNumber) {
-    fixedFormatBitmap[slotNumber >>> 6] |= (1L << (slotNumber & 63));
-    fixedSlotKinds[slotNumber] = NO_FIXED_SLOT_KIND;
-  }
-
-  /**
-   * Mark slot as fixed-layout in-memory representation with explicit kind metadata.
-   */
-  public void markSlotAsFixedFormat(final int slotNumber, final NodeKind nodeKind) {
-    if (nodeKind == null) {
-      throw new IllegalArgumentException("nodeKind must not be null");
-    }
-    fixedFormatBitmap[slotNumber >>> 6] |= (1L << (slotNumber & 63));
-    fixedSlotKinds[slotNumber] = nodeKind.getId();
-  }
-
-  /**
-   * Mark slot as compact serialized representation.
-   */
-  public void markSlotAsCompactFormat(final int slotNumber) {
-    fixedFormatBitmap[slotNumber >>> 6] &= ~(1L << (slotNumber & 63));
-    fixedSlotKinds[slotNumber] = NO_FIXED_SLOT_KIND;
+    return (slotBitmap[slotNumber >>> 6] & (1L << (slotNumber & 63))) != 0;
   }
 
   /**
    * Returns a primitive int array of populated slot indices for O(k) iteration.
    * 

-   * This enables efficient iteration over only populated slots instead of iterating all 1024 slots
-   * and checking for null. For sparse pages with k populated slots, this is O(k) instead of O(1024).
+   * This enables efficient iteration over only populated slots instead of
+   * iterating all 1024 slots and checking for null. For sparse pages with
+   * k populated slots, this is O(k) instead of O(1024).
    * 

-   * Note: This allocates a new array on each call. For hot paths where the same page is iterated
-   * multiple times, consider using {@link #forEachPopulatedSlot}.
+   * Note: This allocates a new array on each call. For hot paths where the
+   * same page is iterated multiple times, consider using {@link #forEachPopulatedSlot}.
    * 

    * Example usage:
-   * 
    * 
{@code
    * int[] slots = page.populatedSlots();
    * for (int i = 0; i < slots.length; i++) {
-   *   int slot = slots[i];
-   *   MemorySegment data = page.getSlot(slot);
-   *   // process data - no null check needed
+   *     int slot = slots[i];
+   *     MemorySegment data = page.getSlot(slot);
+   *     // process data - no null check needed
    * }
    * }

    * 
@@ -1277,17 +1298,20 @@ public int[] populatedSlots() {
 
     // Second pass: collect slot indices using Brian Kernighan's algorithm
     for (int wordIndex = 0; wordIndex < BITMAP_WORDS; wordIndex++) {
-      long word = slotBitmap[wordIndex];
-      int baseSlot = wordIndex << 6; // wordIndex * 64
-      while (word != 0) {
-        int bit = Long.numberOfTrailingZeros(word);
+      final long word = slottedPage != null
+          ? PageLayout.getBitmapWord(slottedPage, wordIndex)
+          : slotBitmap[wordIndex];
+      long remaining = word;
+      final int baseSlot = wordIndex << 6;  // wordIndex * 64
+      while (remaining != 0) {
+        final int bit = Long.numberOfTrailingZeros(remaining);
         result[idx++] = baseSlot + bit;
-        word &= word - 1; // Clear lowest set bit
+        remaining &= remaining - 1;  // Clear lowest set bit
       }
     }
     return result;
   }
-
+  
   /**
    * Functional interface for slot consumer to enable zero-allocation iteration.
    */
@@ -1295,26 +1319,24 @@ public int[] populatedSlots() {
   public interface SlotConsumer {
     /**
      * Process a populated slot.
-     * 
      * @param slotIndex the slot index
      * @return true to continue iteration, false to stop early
      */
     boolean accept(int slotIndex);
   }
-
+  
   /**
    * Zero-allocation iteration over populated slots.
    * 

-   * This method iterates over populated slots without allocating any arrays. The consumer returns
-   * false to stop iteration early.
+   * This method iterates over populated slots without allocating any arrays.
+   * The consumer returns false to stop iteration early.
    * 

    * Example usage:
-   * 
    * 
{@code
    * page.forEachPopulatedSlot(slot -> {
-   *   MemorySegment data = page.getSlot(slot);
-   *   // process data
-   *   return true; // continue iteration
+   *     MemorySegment data = page.getSlot(slot);
+   *     // process data
+   *     return true;  // continue iteration
    * });
    * }

    * 
@@ -1324,28 +1346,34 @@ public interface SlotConsumer {
   public int forEachPopulatedSlot(SlotConsumer consumer) {
     int processed = 0;
     for (int wordIndex = 0; wordIndex < BITMAP_WORDS; wordIndex++) {
-      long word = slotBitmap[wordIndex];
-      int baseSlot = wordIndex << 6; // wordIndex * 64
+      long word = slottedPage != null
+          ? PageLayout.getBitmapWord(slottedPage, wordIndex)
+          : slotBitmap[wordIndex];
+      final int baseSlot = wordIndex << 6;  // wordIndex * 64
       while (word != 0) {
-        int bit = Long.numberOfTrailingZeros(word);
-        int slot = baseSlot + bit;
+        final int bit = Long.numberOfTrailingZeros(word);
+        final int slot = baseSlot + bit;
         processed++;
         if (!consumer.accept(slot)) {
           return processed;
         }
-        word &= word - 1; // Clear lowest set bit
+        word &= word - 1;  // Clear lowest set bit
       }
     }
     return processed;
   }
 
   /**
-   * Get the count of populated slots using SIMD-accelerated population count. Uses Vector API for
-   * parallel bitCount across multiple longs. This is O(BITMAP_WORDS / SIMD_WIDTH) instead of O(1024).
+   * Get the count of populated slots using SIMD-accelerated population count.
+   * Uses Vector API for parallel bitCount across multiple longs.
+   * This is O(BITMAP_WORDS / SIMD_WIDTH) instead of O(1024).
    * 
    * @return number of populated slots
    */
   public int populatedSlotCount() {
+    if (slottedPage != null) {
+      return PageLayout.countPopulatedSlots(slottedPage);
+    }
     int count = 0;
     int i = 0;
 
@@ -1367,13 +1395,16 @@ public int populatedSlotCount() {
 
     return count;
   }
-
+  
   /**
    * Check if all slots are populated using SIMD-accelerated comparison.
    * 
    * @return true if all 1024 slots are populated
    */
   public boolean isFullyPopulated() {
+    if (slottedPage != null) {
+      return PageLayout.countPopulatedSlots(slottedPage) == PageLayout.SLOT_COUNT;
+    }
     // All bits set = 0xFFFFFFFFFFFFFFFF = -1L
     int i = 0;
     final int simdWidth = LONG_SPECIES.length();
@@ -1386,7 +1417,7 @@ public boolean isFullyPopulated() {
         return false;
       }
     }
-
+    
     // Scalar tail
     for (; i < BITMAP_WORDS; i++) {
       if (slotBitmap[i] != -1L) {
@@ -1395,10 +1426,10 @@ public boolean isFullyPopulated() {
     }
     return true;
   }
-
+  
   /**
-   * SIMD-accelerated bitmap OR into destination array. Computes: dest[i] |= src[i] for all bitmap
-   * words.
+   * SIMD-accelerated bitmap OR into destination array.
+   * Computes: dest[i] |= src[i] for all bitmap words.
    * 
    * @param dest destination bitmap (modified in place)
    * @param src source bitmap to OR into dest
@@ -1407,22 +1438,23 @@ public static void bitmapOr(long[] dest, long[] src) {
     int i = 0;
     final int simdWidth = LONG_SPECIES.length();
     final int simdBound = BITMAP_WORDS - (BITMAP_WORDS % simdWidth);
-
+    
     for (; i < simdBound; i += simdWidth) {
       LongVector destVec = LongVector.fromArray(LONG_SPECIES, dest, i);
       LongVector srcVec = LongVector.fromArray(LONG_SPECIES, src, i);
       destVec.or(srcVec).intoArray(dest, i);
     }
-
+    
     // Scalar tail
     for (; i < BITMAP_WORDS; i++) {
       dest[i] |= src[i];
     }
   }
-
+  
   /**
-   * Check if any bits in src are NOT set in dest using SIMD. Returns true if there exist slots in src
-   * that are not yet in dest. Useful for early termination in page combining.
+   * Check if any bits in src are NOT set in dest using SIMD.
+   * Returns true if there exist slots in src that are not yet in dest.
+   * Useful for early termination in page combining.
    * 
    * @param dest the "filled" bitmap
    * @param src the source bitmap to check
@@ -1432,7 +1464,7 @@ public static boolean hasNewBits(long[] dest, long[] src) {
     int i = 0;
     final int simdWidth = LONG_SPECIES.length();
     final int simdBound = BITMAP_WORDS - (BITMAP_WORDS % simdWidth);
-
+    
     for (; i < simdBound; i += simdWidth) {
       LongVector destVec = LongVector.fromArray(LONG_SPECIES, dest, i);
       LongVector srcVec = LongVector.fromArray(LONG_SPECIES, src, i);
@@ -1442,7 +1474,7 @@ public static boolean hasNewBits(long[] dest, long[] src) {
         return true;
       }
     }
-
+    
     // Scalar tail
     for (; i < BITMAP_WORDS; i++) {
       if ((src[i] & ~dest[i]) != 0) {
@@ -1452,141 +1484,49 @@ public static boolean hasNewBits(long[] dest, long[] src) {
     return false;
   }
 
-  /**
-   * Get the slot memory segment for zero-copy serialization. Contains the raw serialized slot data.
-   * 
-   * @return the slot memory segment
-   */
-  public MemorySegment getSlotMemory() {
-    return slotMemory;
-  }
 
   /**
-   * Get the dewey ID offsets array for zero-copy serialization. Each element is the byte offset
-   * within deweyIdMemory where the dewey ID's data begins, or -1 if empty.
-   * 
-   * @return the dewey ID offsets array (do not modify)
+   * Get the slotted page MemorySegment for serialization.
+   * When non-null, the page uses LeanStore-style heap storage instead of legacy slotMemory.
+   *
+   * @return the slotted page segment, or null if not yet initialized
    */
-  public int[] getDeweyIdOffsets() {
-    return deweyIdOffsets;
+  public MemorySegment getSlottedPage() {
+    return slottedPage;
   }
 
   /**
-   * Get the dewey ID memory segment for zero-copy serialization. Contains the raw serialized dewey ID
-   * data.
-   * 
-   * @return the dewey ID memory segment (may be null if not stored)
+   * Set the slotted page MemorySegment (used during deserialization).
+   * Releases any previously allocated slotted page.
+   *
+   * @param slottedPage the slotted page segment
    */
-  public MemorySegment getDeweyIdMemory() {
-    return deweyIdMemory;
-  }
-
-  MemorySegment resizeMemorySegment(MemorySegment oldMemory, int newSize, int[] offsets, boolean isSlotMemory) {
-    MemorySegment newMemory = segmentAllocator.allocate(newSize);
-    MemorySegment.copy(oldMemory, 0, newMemory, 0, oldMemory.byteSize());
-    segmentAllocator.release(oldMemory);
-
-    if (isSlotMemory) {
-      slotMemory = newMemory;
-    } else {
-      deweyIdMemory = newMemory;
-    }
-
-    // Update offsets to reference the new memory segment.
-    for (int i = 0; i < offsets.length; i++) {
-      if (offsets[i] >= 0) {
-        offsets[i] = alignOffset(offsets[i]);
-        updateLastSlotIndex(i, isSlotMemory);
-      }
+  public void setSlottedPage(final MemorySegment newSlottedPage) {
+    // Release old slotted page if different from the new one
+    if (this.slottedPage != null && this.slottedPage != newSlottedPage) {
+      segmentAllocator.release(this.slottedPage.reinterpret(slottedPageCapacity));
     }
+    this.slottedPageCapacity = (int) newSlottedPage.byteSize();
+    this.slottedPage = newSlottedPage.reinterpret(Long.MAX_VALUE);
+  }
 
-    // Update slotMemoryFreeSpaceStart to reflect the new free space start position.
-    updateFreeSpaceStart(offsets, newMemory, isSlotMemory);
 
-    return newMemory;
-  }
 
   @Override
   public int getUsedDeweyIdSize() {
-    return getUsedByteSize(deweyIdOffsets, deweyIdMemory);
+    // DeweyIDs are inline in the slotted page heap — no separate memory
+    return 0;
   }
 
   @Override
   public int getUsedSlotsSize() {
-    return getUsedByteSize(slotOffsets, slotMemory);
+    return slottedPage != null ? PageLayout.getHeapUsed(slottedPage) : 0;
   }
 
   public int getSlotMemoryByteSize() {
-    return (int) slotMemory.byteSize();
-  }
-
-  public int getDeweyIdMemoryByteSize() {
-    return (int) deweyIdMemory.byteSize();
-  }
-
-  int getUsedByteSize(int[] offsets, MemorySegment memory) {
-    if (memory == null) {
-      return 0;
-    }
-    return (int) memory.byteSize() - getAvailableSpace(offsets, memory);
+    return slottedPage != null ? PageLayout.HEAP_START + PageLayout.getHeapEnd(slottedPage) : 0;
   }
 
-  private void shiftSlotMemory(int slotNumber, int sizeDelta, int[] offsets, MemorySegment memory) {
-    if (sizeDelta == 0) {
-      return; // No shift needed if there's no size change.
-    }
-
-    boolean isSlotMemory = memory == slotMemory;
-
-    // Find the start offset of the slot to be shifted.
-    int startOffset = offsets[slotNumber];
-    int alignedStartOffset = alignOffset(startOffset);
-
-    // Find the smallest offset greater than the current slot's offset.
-    int shiftStartOffset = Integer.MAX_VALUE;
-    for (int i = 0; i < offsets.length; i++) {
-      if (i != slotNumber && offsets[i] >= alignedStartOffset && offsets[i] < shiftStartOffset) {
-        shiftStartOffset = offsets[i];
-      }
-    }
-
-    if (shiftStartOffset == Integer.MAX_VALUE) {
-      return;
-    }
-    int alignedShiftStartOffset = alignOffset(shiftStartOffset);
-
-    // Calculate the end offset of the memory region to shift.
-    int lastSlotIndex = getLastIndex(isSlotMemory);
-    int alignedEndOffset = alignOffset(offsets[lastSlotIndex]);
-
-    // Calculate the size of the last slot, ensuring it is aligned.
-    int lastSlotSize = INT_SIZE + memory.get(ValueLayout.JAVA_INT, alignedEndOffset);
-
-    // Calculate the end offset of the shift.
-    int shiftEndOffset = alignedEndOffset + lastSlotSize;
-
-    // Ensure the target slice also stays within bounds.
-    long targetEndOffset =
-        alignOffset(alignedShiftStartOffset + sizeDelta) + (shiftEndOffset - alignedShiftStartOffset);
-    if (targetEndOffset > memory.byteSize()) {
-      throw new IndexOutOfBoundsException("Calculated targetEndOffset exceeds memory bounds. " + "targetEndOffset: "
-          + targetEndOffset + ", memory size: " + memory.byteSize() + ", slotNumber: " + (slotNumber - 1));
-    }
-
-    // Shift the memory.
-    // Bulk copy: MemorySegment.copy handles overlapping regions safely (memmove semantics).
-    final int dstOffset = alignOffset(alignedShiftStartOffset + sizeDelta);
-    final long copyLength = shiftEndOffset - alignedShiftStartOffset;
-    MemorySegment.copy(memory, alignedShiftStartOffset, memory, dstOffset, copyLength);
-
-    // Adjust the offsets for all affected slots.
-    for (int i = 0; i < offsets.length; i++) {
-      if (i != slotNumber && offsets[i] >= alignedStartOffset) {
-        offsets[i] = alignOffset(offsets[i] + sizeDelta);
-        updateLastSlotIndex(i, isSlotMemory);
-      }
-    }
-  }
 
   @Override
   public byte[] getSlotAsByteArray(int slotNumber) {
@@ -1602,205 +1542,23 @@ public byte[] getSlotAsByteArray(int slotNumber) {
   }
 
   public boolean isSlotSet(int slotNumber) {
-    return slotOffsets[slotNumber] != -1;
-  }
-
-  /**
-   * Get the absolute data offset for a slot within {@link #getSlotMemory()}, skipping the 4-byte
-   * length prefix. Use together with {@link #getSlotDataLength(int)} and {@link #getSlotMemory()} to
-   * avoid allocating a {@code MemorySegment} slice on the hot path.
-   *
-   * @param slotNumber the slot index
-   * @return absolute byte offset into slotMemory where data begins, or {@code -1} if the slot is
-   *         empty
-   */
-  public long getSlotDataOffset(final int slotNumber) {
-    assert slotNumber >= 0 && slotNumber < slotOffsets.length : "Invalid slot number: " + slotNumber;
-    final int slotOffset = slotOffsets[slotNumber];
-    if (slotOffset < 0) {
-      return -1;
-    }
-    return slotOffset + INT_SIZE;
-  }
-
-  /**
-   * Get the data length (in bytes) stored in the given slot, excluding the 4-byte length prefix. Use
-   * together with {@link #getSlotDataOffset(int)} and {@link #getSlotMemory()} to avoid allocating a
-   * {@code MemorySegment} slice on the hot path.
-   *
-   * @param slotNumber the slot index
-   * @return data length in bytes, or {@code -1} if the slot is empty
-   */
-  public int getSlotDataLength(final int slotNumber) {
-    assert slotNumber >= 0 && slotNumber < slotOffsets.length : "Invalid slot number: " + slotNumber;
-    final int slotOffset = slotOffsets[slotNumber];
-    if (slotOffset < 0) {
-      return -1;
-    }
-    return slotMemory.get(JAVA_INT_UNALIGNED, slotOffset);
+    return slottedPage != null && PageLayout.isSlotPopulated(slottedPage, slotNumber);
   }
 
   @Override
   public MemorySegment getSlot(int slotNumber) {
-    // Validate slot memory segment
-    assert slotMemory != null : "Slot memory segment is null";
-    assert slotMemory.byteSize() > 0 : "Slot memory segment has zero length. Page key: " + recordPageKey
-        + ", revision: " + revision + ", index type: " + indexType;
-
-    // Validate slot number
-    assert slotNumber >= 0 && slotNumber < slotOffsets.length : "Invalid slot number: " + slotNumber;
-
-    int slotOffset = slotOffsets[slotNumber];
-    if (slotOffset < 0) {
+    if (slottedPage == null || !PageLayout.isSlotPopulated(slottedPage, slotNumber)) {
       return null;
     }
-
-    // CRITICAL: Validate memory segment state before reading
-    if (slotMemory == null) {
-      throw new IllegalStateException("Slot memory is null for page " + recordPageKey);
-    }
-
-    // DEFENSIVE: Ensure offset is within segment bounds BEFORE reading
-    if (slotOffset + INT_SIZE > slotMemory.byteSize()) {
-      throw new IllegalStateException(
-          String.format("CORRUPT OFFSET: slot %d has offset %d but would exceed segment (size %d, page %d, rev %d)",
-              slotNumber, slotOffset, slotMemory.byteSize(), recordPageKey, revision));
-    }
-
-    // Read the length from the first 4 bytes at the offset
-    // Use unaligned access because zero-copy slices may not be 4-byte aligned
-    int length;
-    try {
-      length = slotMemory.get(JAVA_INT_UNALIGNED, slotOffset);
-    } catch (Exception e) {
-      throw new IllegalStateException(
-          String.format("Failed to read length at offset %d (page %d, slot %d, memory size %d)", slotOffset,
-              recordPageKey, slotNumber, slotMemory.byteSize()),
-          e);
-    }
-
-    // DEFENSIVE: Sanity check the length value before using it
-    if (length < 0 || length > slotMemory.byteSize()) {
-      throw new IllegalStateException(
-          String.format("CORRUPT LENGTH at offset %d: %d (segment size: %d, page %d, slot %d, revision: %d)",
-              slotOffset, length, slotMemory.byteSize(), recordPageKey, slotNumber, revision));
-    }
-
-    if (length <= 0) {
-      // Print memory segment contents around the failing offset
-      String memoryDump = dumpMemorySegmentAroundOffset(slotOffset, slotNumber);
-
-      String errorMessage = String.format(
-          "Slot length must be greater than 0, but is %d (slotNumber: %d, offset: %d, revision: %d, page: %d)", length,
-          slotNumber, slotOffset, revision, recordPageKey);
-
-      // Add comprehensive debugging info
-      String debugInfo = String.format(
-          "%s\nMemory segment: size=%d, closed=%s\nSlot offsets around %d: [%d, %d, %d]\nLast slot index: %d, Free space: %d\n%s",
-          errorMessage, slotMemory.byteSize(), isClosed(), slotNumber, slotNumber > 0
-              ? slotOffsets[slotNumber - 1]
-              : -1,
-          slotOffsets[slotNumber], slotNumber < slotOffsets.length - 1
-              ? slotOffsets[slotNumber + 1]
-              : -1,
-          lastSlotIndex, slotMemoryFreeSpaceStart, memoryDump);
-
-      throw new AssertionError(createStackTraceMessage(debugInfo));
-    }
-
-
-    // Validate that we can read the full data
-    if (slotOffset + INT_SIZE + length > slotMemory.byteSize()) {
-      throw new IllegalStateException(
-          String.format("Slot data extends beyond memory segment: offset=%d, length=%d, total=%d, memory_size=%d",
-              slotOffset, length, slotOffset + INT_SIZE + length, slotMemory.byteSize()));
+    final int heapOffset = PageLayout.getDirHeapOffset(slottedPage, slotNumber);
+    // Use record-only length (excludes inline DeweyID data + 2-byte trailer)
+    final int recordLength = PageLayout.getRecordOnlyLength(slottedPage, slotNumber);
+    if (recordLength <= 0) {
+      return null;
     }
-
-    // Return the memory segment containing just the data (skip the 4-byte length prefix)
-    return slotMemory.asSlice(slotOffset + INT_SIZE, length);
+    return slottedPage.asSlice(PageLayout.HEAP_START + heapOffset, recordLength);
   }
 
-  /**
-   * Dump the memory segment contents around a specific offset for debugging purposes.
-   *
-   * @param offset the offset where the issue occurred
-   * @param slotNumber the slot number for context
-   * @return a formatted string showing the memory contents
-   */
-  private String dumpMemorySegmentAroundOffset(int offset, int slotNumber) {
-    StringBuilder sb = new StringBuilder();
-    sb.append("Memory segment dump around failing offset:\n");
-
-    // Show 64 bytes around the offset (32 before, 32 after)
-    int startOffset = Math.max(0, offset - 32);
-    int endOffset = Math.min((int) slotMemory.byteSize(), offset + 64);
-
-    sb.append(
-        String.format("Dumping bytes %d to %d (offset %d marked with **):\n", startOffset, endOffset - 1, offset));
-
-    // Hex dump with 16 bytes per line
-    for (int i = startOffset; i < endOffset; i += 16) {
-      sb.append(String.format("%04X: ", i));
-
-      // Hex bytes
-      for (int j = 0; j < 16 && i + j < endOffset; j++) {
-        byte b = slotMemory.get(ValueLayout.JAVA_BYTE, i + j);
-        if (i + j == offset) {
-          sb.append(String.format("**%02X** ", b & 0xFF));
-        } else {
-          sb.append(String.format("%02X ", b & 0xFF));
-        }
-      }
-
-      // ASCII representation
-      sb.append(" |");
-      for (int j = 0; j < 16 && i + j < endOffset; j++) {
-        byte b = slotMemory.get(ValueLayout.JAVA_BYTE, i + j);
-        char c = (b >= 32 && b < 127)
-            ? (char) b
-            : '.';
-        if (i + j == offset) {
-          sb.append('*');
-        } else {
-          sb.append(c);
-        }
-      }
-      sb.append("|\n");
-    }
-
-    // Also show the specific 4 bytes that should contain the length
-    sb.append(String.format("\nSpecific 4-byte length value at offset %d:\n", offset));
-    if (offset + 4 <= slotMemory.byteSize()) {
-      for (int i = 0; i < 4; i++) {
-        byte b = slotMemory.get(ValueLayout.JAVA_BYTE, offset + i);
-        sb.append(String.format("Byte %d: 0x%02X (%d)\n", i, b & 0xFF, b));
-      }
-
-      // Show as little-endian and big-endian integers
-      try {
-        int littleEndian = slotMemory.get(ValueLayout.JAVA_INT.withOrder(ByteOrder.LITTLE_ENDIAN), offset);
-        int bigEndian = slotMemory.get(ValueLayout.JAVA_INT.withOrder(ByteOrder.BIG_ENDIAN), offset);
-        sb.append(String.format("As little-endian int: %d\n", littleEndian));
-        sb.append(String.format("As big-endian int: %d\n", bigEndian));
-      } catch (Exception e) {
-        sb.append("Failed to read as integer: ").append(e.getMessage()).append('\n');
-      }
-    }
-
-    // Show all slot offsets for context
-    sb.append("\nAll slot offsets:\n");
-    for (int i = 0; i < slotOffsets.length; i++) {
-      if (slotOffsets[i] >= 0) {
-        sb.append(String.format("Slot %d: offset %d", i, slotOffsets[i]));
-        if (i == slotNumber) {
-          sb.append(" <- FAILING SLOT");
-        }
-        sb.append('\n');
-      }
-    }
-
-    return sb.toString();
-  }
 
 
   private static String createStackTraceMessage(String message) {
@@ -1817,32 +1575,102 @@ private static String createStackTraceMessage(String message) {
 
   @Override
   public void setDeweyId(byte[] deweyId, int offset) {
-    var memorySegment = setData(MemorySegment.ofArray(deweyId), offset, deweyIdOffsets, deweyIdMemory);
-
-    if (memorySegment != null) {
-      deweyIdMemory = memorySegment;
+    if (deweyId == null) {
+      return;
     }
+    ensureSlottedPage();
+    setDeweyIdToHeap(MemorySegment.ofArray(deweyId), offset);
   }
 
   @Override
   public void setDeweyId(MemorySegment deweyId, int offset) {
-    var memorySegment = setData(deweyId, offset, deweyIdOffsets, deweyIdMemory);
+    if (deweyId == null) {
+      return;
+    }
+    ensureSlottedPage();
+    setDeweyIdToHeap(deweyId, offset);
+  }
+
+  /**
+   * Set a DeweyID for a slot by re-allocating the slot's heap region with DeweyID data appended.
+   * Format: [record data][deweyId data][deweyIdLen:2 bytes (u16)].
+   * The old allocation becomes dead heap space.
+   */
+  private void setDeweyIdToHeap(final MemorySegment deweyId, final int slotNumber) {
+    final int deweyIdLen = (int) deweyId.byteSize();
+    if (deweyIdLen == 0) {
+      return;
+    }
+
+    final boolean slotExists = PageLayout.isSlotPopulated(slottedPage, slotNumber);
+    final int oldDataLength;
+    final int recordLen;
+    final int nodeKindId;
+    final long oldAbsStart;
+
+    if (slotExists) {
+      // Existing slot — read current allocation info
+      final int oldHeapOffset = PageLayout.getDirHeapOffset(slottedPage, slotNumber);
+      oldDataLength = PageLayout.getDirDataLength(slottedPage, slotNumber);
+      nodeKindId = PageLayout.getDirNodeKindId(slottedPage, slotNumber);
+      recordLen = PageLayout.getRecordOnlyLength(slottedPage, slotNumber);
+      oldAbsStart = PageLayout.heapAbsoluteOffset(oldHeapOffset);
+    } else {
+      // No record yet — DeweyID-only allocation (nodeKindId = 0)
+      oldDataLength = 0;
+      recordLen = 0;
+      nodeKindId = 0;
+      oldAbsStart = 0; // unused
+    }
+
+    // New total: record + deweyId + 2-byte trailer
+    final int newTotalLen = recordLen + deweyIdLen + PageLayout.DEWEY_ID_TRAILER_SIZE;
+
+    // Ensure heap has enough space
+    int heapEnd = PageLayout.getHeapEnd(slottedPage);
+    int remaining = slottedPageCapacity - PageLayout.HEAP_START - heapEnd;
+    while (remaining < newTotalLen) {
+      growSlottedPage();
+      heapEnd = PageLayout.getHeapEnd(slottedPage);
+      remaining = slottedPageCapacity - PageLayout.HEAP_START - heapEnd;
+    }
+
+    // Bump-allocate new space
+    final long newAbsStart = PageLayout.heapAbsoluteOffset(heapEnd);
+
+    // Copy record data from old location (if any)
+    if (recordLen > 0) {
+      MemorySegment.copy(slottedPage, oldAbsStart, slottedPage, newAbsStart, recordLen);
+    }
+
+    // Copy DeweyID data
+    MemorySegment.copy(deweyId, 0, slottedPage, newAbsStart + recordLen, deweyIdLen);
+
+    // Write DeweyID length trailer (u16 at end)
+    PageLayout.writeDeweyIdTrailer(slottedPage, newAbsStart + newTotalLen, deweyIdLen);
+
+    // Update heap end (heapUsed: add new, subtract old dead space)
+    PageLayout.setHeapEnd(slottedPage, heapEnd + newTotalLen);
+    PageLayout.setHeapUsed(slottedPage,
+        PageLayout.getHeapUsed(slottedPage) + newTotalLen - oldDataLength);
 
-    if (memorySegment != null) {
-      deweyIdMemory = memorySegment;
+    // Update directory entry
+    PageLayout.setDirEntry(slottedPage, slotNumber, heapEnd, newTotalLen, nodeKindId);
+
+    // Mark slot populated if new
+    if (!slotExists) {
+      PageLayout.markSlotPopulated(slottedPage, slotNumber);
+      PageLayout.setPopulatedCount(slottedPage,
+          PageLayout.getPopulatedCount(slottedPage) + 1);
     }
   }
 
   @Override
   public MemorySegment getDeweyId(int offset) {
-    int deweyIdOffset = deweyIdOffsets[offset];
-    if (deweyIdOffset < 0) {
+    if (slottedPage == null || !PageLayout.isSlotPopulated(slottedPage, offset)) {
       return null;
     }
-    // Use unaligned access because zero-copy slices may not be 4-byte aligned
-    int deweyIdLength = deweyIdMemory.get(JAVA_INT_UNALIGNED, deweyIdOffset);
-    deweyIdOffset += INT_SIZE;
-    return deweyIdMemory.asSlice(deweyIdOffset, deweyIdLength);
+    return PageLayout.getDeweyId(slottedPage, offset);
   }
 
   @Override
@@ -1856,47 +1684,19 @@ public byte[] getDeweyIdAsByteArray(int slotNumber) {
     return memorySegment.toArray(ValueLayout.JAVA_BYTE);
   }
 
-  public int findFreeSpaceForSlots(int requiredSize, boolean isSlotMemory) {
-    // Align the start of the free space
-    int alignedFreeSpaceStart = alignOffset(isSlotMemory
-        ? slotMemoryFreeSpaceStart
-        : deweyIdMemoryFreeSpaceStart);
-    int freeSpaceEnd = isSlotMemory
-        ? (int) slotMemory.byteSize()
-        : (int) deweyIdMemory.byteSize();
-
-    // Check if there's enough space in the current free space range
-    if (freeSpaceEnd - alignedFreeSpaceStart >= requiredSize) {
-      return alignedFreeSpaceStart;
-    }
-
-    int freeMemoryStart = isSlotMemory
-        ? slotMemoryFreeSpaceStart
-        : deweyIdMemoryFreeSpaceStart;
-    int freeMemoryEnd = isSlotMemory
-        ? (int) slotMemory.byteSize()
-        : (int) deweyIdMemory.byteSize();
-    throw new IllegalStateException("Not enough space in memory segment to store the data (freeSpaceStart "
-        + freeMemoryStart + " requiredSize: " + requiredSize + ", maxLength: " + freeMemoryEnd + ")");
-  }
 
   @Override
   public > C newInstance(@NonNegative long recordPageKey,
       @NonNull IndexType indexType, @NonNull StorageEngineReader storageEngineReader) {
-    // Direct allocation (no pool)
-    ResourceConfiguration config = storageEngineReader.getResourceSession().getResourceConfig();
-    MemorySegmentAllocator allocator = OS.isWindows()
-        ? WindowsMemorySegmentAllocator.getInstance()
-        : LinuxMemorySegmentAllocator.getInstance();
-
-    MemorySegment slotMemory = allocator.allocate(SIXTYFOUR_KB);
-    MemorySegment deweyIdMemory = config.areDeweyIDsStored
-        ? allocator.allocate(SIXTYFOUR_KB)
-        : null;
-
-    // Memory allocated from global allocator - should be released on close()
-    return (C) new KeyValueLeafPage(recordPageKey, indexType, config, storageEngineReader.getRevisionNumber(), slotMemory,
-        deweyIdMemory, false // NOT externally allocated - release memory on close()
+    final ResourceConfiguration config = storageEngineReader.getResourceSession().getResourceConfig();
+    return (C) new KeyValueLeafPage(
+        recordPageKey,
+        indexType,
+        config,
+        storageEngineReader.getRevisionNumber(),
+        null,
+        null,
+        false
     );
   }
 
@@ -1913,7 +1713,7 @@ public String toString() {
 
   @Override
   public int size() {
-    return getNumberOfNonNullEntries(records) + (references != null ? references.size() : 0);
+    return getNumberOfNonNullEntries(records) + references.size();
   }
 
   private int getNumberOfNonNullEntries(final DataRecord[] entries) {
@@ -1935,12 +1735,12 @@ public boolean isClosed() {
   /**
    * Finalizer for detecting page leaks during development.
    * 

-   * This method logs a warning if a page is garbage collected without being properly closed,
-   * indicating a potential memory leak. The warning is only generated when diagnostic settings are
-   * enabled.
+   * This method logs a warning if a page is garbage collected without being
+   * properly closed, indicating a potential memory leak. The warning is only
+   * generated when diagnostic settings are enabled.
    * 

-   * Note: Finalizers are deprecated in modern Java. This is retained solely for leak detection
-   * during development and testing.
+   * Note: Finalizers are deprecated in modern Java. This is retained
+   * solely for leak detection during development and testing.
    *
    * @deprecated Finalizers are discouraged. This exists only for leak detection.
    */
@@ -1949,26 +1749,25 @@ public boolean isClosed() {
   protected void finalize() {
     if (!isClosed() && DEBUG_MEMORY_LEAKS) {
       PAGES_FINALIZED_WITHOUT_CLOSE.incrementAndGet();
-
+      
       // Track by type and pageKey for detailed leak analysis
       if (indexType != null) {
-        FINALIZED_BY_TYPE.computeIfAbsent(indexType, _ -> new java.util.concurrent.atomic.AtomicLong(0))
-                         .incrementAndGet();
+        FINALIZED_BY_TYPE.computeIfAbsent(indexType, _ -> new java.util.concurrent.atomic.AtomicLong(0)).incrementAndGet();
       }
-      FINALIZED_BY_PAGE_KEY.computeIfAbsent(recordPageKey, _ -> new java.util.concurrent.atomic.AtomicLong(0))
-                           .incrementAndGet();
-
+      FINALIZED_BY_PAGE_KEY.computeIfAbsent(recordPageKey, _ -> new java.util.concurrent.atomic.AtomicLong(0)).incrementAndGet();
+      
       // Log leak information (only when diagnostics enabled)
       if (LOGGER.isWarnEnabled()) {
         StringBuilder leakMsg = new StringBuilder();
         leakMsg.append(String.format("Page leak detected: pageKey=%d, type=%s, revision=%d - not closed explicitly",
             recordPageKey, indexType, revision));
-
+        
         if (creationStackTrace != null && LOGGER.isDebugEnabled()) {
           leakMsg.append("\n  Creation stack trace:");
           for (int i = 2; i < Math.min(creationStackTrace.length, 8); i++) {
             StackTraceElement frame = creationStackTrace[i];
-            leakMsg.append(String.format("\n    at %s.%s(%s:%d)", frame.getClassName(), frame.getMethodName(),
+            leakMsg.append(String.format("\n    at %s.%s(%s:%d)",
+                frame.getClassName(), frame.getMethodName(),
                 frame.getFileName(), frame.getLineNumber()));
           }
         }
@@ -1980,14 +1779,15 @@ protected void finalize() {
   /**
    * Closes this page and releases associated memory resources.
    * 

-   * This method is thread-safe and idempotent. If the page has active guards (indicating it's in use
-   * by a transaction), the close operation is skipped to prevent data corruption.
+   * This method is thread-safe and idempotent. If the page has active guards
+   * (indicating it's in use by a transaction), the close operation is skipped
+   * to prevent data corruption.
    * 

-   * Memory segments allocated by the global allocator are returned to the pool. Externally allocated
-   * memory (e.g., test arenas) is not released.
+   * Memory segments allocated by the global allocator are returned to the pool.
+   * Externally allocated memory (e.g., test arenas) is not released.
    * 

-   * For zero-copy pages, the backing buffer (from decompression) is released via the
-   * backingBufferReleaser callback.
+   * For zero-copy pages, the backing buffer (from decompression) is released
+   * via the backingBufferReleaser callback.
    */
   @Override
   public synchronized void close() {
@@ -2001,8 +1801,8 @@ public synchronized void close() {
     int currentGuardCount = guardCount.get();
     if (currentGuardCount > 0) {
       if (LOGGER.isDebugEnabled()) {
-        LOGGER.debug("Close skipped for guarded page: pageKey={}, type={}, guardCount={}", recordPageKey, indexType,
-            currentGuardCount);
+        LOGGER.debug("Close skipped for guarded page: pageKey={}, type={}, guardCount={}",
+            recordPageKey, indexType, currentGuardCount);
       }
       return;
     }
@@ -2017,8 +1817,7 @@ public synchronized void close() {
     // Update diagnostic counters if tracking is enabled
     if (DEBUG_MEMORY_LEAKS) {
       PAGES_CLOSED.incrementAndGet();
-      PAGES_CLOSED_BY_TYPE.computeIfAbsent(indexType, _ -> new java.util.concurrent.atomic.AtomicLong(0))
-                          .incrementAndGet();
+      PAGES_CLOSED_BY_TYPE.computeIfAbsent(indexType, _ -> new java.util.concurrent.atomic.AtomicLong(0)).incrementAndGet();
       ALL_LIVE_PAGES.remove(this);
       if (recordPageKey == 0) {
         ALL_PAGE_0_INSTANCES.remove(this);
@@ -2034,63 +1833,61 @@ public synchronized void close() {
       }
       backingBufferReleaser = null;
       backingBuffer = null;
-      // For zero-copy pages, all memory segments are slices of backingBuffer, don't release separately
-      slotMemory = null;
-      deweyIdMemory = null;
-      stringValueMemory = null; // CRITICAL: Must be nulled for columnar string storage
+      stringValueMemory = null;  // CRITICAL: Must be nulled for columnar string storage
     } else if (!externallyAllocatedMemory) {
-      // Release memory segments to the allocator pool (non-zero-copy path)
+      // Release memory segments to the allocator pool
       try {
-        if (slotMemory != null && slotMemory.byteSize() > 0) {
-          segmentAllocator.release(slotMemory);
-        }
-        if (deweyIdMemory != null && deweyIdMemory.byteSize() > 0) {
-          segmentAllocator.release(deweyIdMemory);
-        }
         if (stringValueMemory != null && stringValueMemory.byteSize() > 0) {
           segmentAllocator.release(stringValueMemory);
         }
       } catch (Throwable e) {
         LOGGER.debug("Failed to release memory segments for page {}: {}", recordPageKey, e.getMessage());
       }
-      slotMemory = null;
-      deweyIdMemory = null;
       stringValueMemory = null;
     }
+    
+    // Unbind all flyweight nodes BEFORE releasing memory — they may still be
+    // referenced by cursors/transactions and must fall back to Java field values.
+    if (slottedPage != null) {
+      for (final DataRecord record : records) {
+        if (record instanceof FlyweightNode fn && fn.isBound()) {
+          fn.unbind();
+        }
+      }
+      try {
+        segmentAllocator.release(slottedPage.reinterpret(slottedPageCapacity));
+      } catch (Throwable e) {
+        LOGGER.debug("Failed to release slotted page for page {}: {}", recordPageKey, e.getMessage());
+      }
+      slottedPage = null;
+      slottedPageCapacity = 0;
+    }
 
     // Clear FSST symbol table
     fsstSymbolTable = null;
-    parsedFsstSymbols = null;
 
     // Clear references to aid garbage collection
     Arrays.fill(records, null);
-    inMemoryRecordCount = 0;
-    demotionThreshold = MIN_DEMOTION_THRESHOLD;
-    rematerializedRecordsSinceLastDemotion = 0;
-    if (references != null) {
-      references.clear();
-    }
+    references.clear();
     bytes = null;
+    compressedSegment = null;
     hashCode = null;
   }
 
   /**
-   * Get the actual memory size used by this page's memory segments. Used for accurate Caffeine cache
-   * weighing.
+   * Get the actual memory size used by this page's memory segments.
+   * Used for accurate Caffeine cache weighing.
    * 
    * @return Total size in bytes of all memory segments used by this page
    */
   public long getActualMemorySize() {
     long total = 0;
-    if (slotMemory != null) {
-      total += slotMemory.byteSize();
-    }
-    if (deweyIdMemory != null) {
-      total += deweyIdMemory.byteSize();
-    }
     if (stringValueMemory != null) {
       total += stringValueMemory.byteSize();
     }
+    if (slottedPage != null) {
+      total += slottedPageCapacity;
+    }
     return total;
   }
 
@@ -2104,24 +1901,12 @@ public byte[] getFsstSymbolTable() {
   }
 
   /**
-   * Set the FSST symbol table for string compression. Pre-parses the symbol table to avoid
-   * redundant parsing on every encode/decode call.
-   *
+   * Set the FSST symbol table for string compression.
+   * 
    * @param symbolTable the symbol table bytes
    */
   public void setFsstSymbolTable(byte[] symbolTable) {
     this.fsstSymbolTable = symbolTable;
-    this.parsedFsstSymbols =
-        (symbolTable != null && symbolTable.length > 0) ? FSSTCompressor.parseSymbolTable(symbolTable) : null;
-  }
-
-  /**
-   * Get the pre-parsed FSST symbol table.
-   *
-   * @return the parsed symbol arrays, or null if FSST is not used
-   */
-  public byte[][] getParsedFsstSymbols() {
-    return parsedFsstSymbols;
   }
 
   /**
@@ -2134,12 +1919,12 @@ public MemorySegment getStringValueSegment(int slotNumber) {
     if (stringValueMemory == null || slotNumber < 0 || slotNumber >= stringValueOffsets.length) {
       return null;
     }
-
+    
     int offset = stringValueOffsets[slotNumber];
     if (offset < 0) {
       return null;
     }
-
+    
     // Calculate length: either to next offset or to end of used space
     int length;
     if (slotNumber == lastStringValueIndex) {
@@ -2159,11 +1944,11 @@ public MemorySegment getStringValueSegment(int slotNumber) {
         length = stringValueMemoryFreeSpaceStart - offset;
       }
     }
-
+    
     if (length <= 0) {
       return null;
     }
-
+    
     return stringValueMemory.asSlice(offset, length);
   }
 
@@ -2175,11 +1960,15 @@ public MemorySegment getStringValueSegment(int slotNumber) {
    * @param lastStringValueIndex the index of the last string value slot
    * @param stringValueMemoryFreeSpaceStart the end of used space in stringValueMemory
    */
-  public void setStringValueData(MemorySegment stringValueMemory, int[] stringValueOffsets, int lastStringValueIndex,
-      int stringValueMemoryFreeSpaceStart) {
+  public void setStringValueData(
+      MemorySegment stringValueMemory,
+      int[] stringValueOffsets,
+      int lastStringValueIndex,
+      int stringValueMemoryFreeSpaceStart
+  ) {
     this.stringValueMemory = stringValueMemory;
     if (stringValueOffsets != null) {
-      System.arraycopy(stringValueOffsets, 0, this.stringValueOffsets, 0,
+      System.arraycopy(stringValueOffsets, 0, this.stringValueOffsets, 0, 
           Math.min(stringValueOffsets.length, this.stringValueOffsets.length));
     }
     this.lastStringValueIndex = lastStringValueIndex;
@@ -2233,23 +2022,16 @@ public int getStringValueMemoryFreeSpaceStart() {
 
   @Override
   public List getReferences() {
-    if (references == null || references.isEmpty()) {
-      return List.of();
-    }
     return List.of(references.values().toArray(new PageReference[0]));
   }
 
   @Override
-  public void commit(final @NonNull StorageEngineWriter storageEngineWriter) {
-    addReferences(storageEngineWriter.getResourceSession().getResourceConfig());
-    final var refs = references;
-    if (refs == null) {
-      return;
-    }
-    for (final PageReference reference : refs.values()) {
+  public void commit(final @NonNull StorageEngineWriter pageWriteTrx) {
+    addReferences(pageWriteTrx.getResourceSession().getResourceConfig());
+    for (final PageReference reference : references.values()) {
       if (!(reference.getPage() == null && reference.getKey() == Constants.NULL_ID_LONG
           && reference.getLogKey() == Constants.NULL_ID_LONG)) {
-        storageEngineWriter.commit(reference);
+        pageWriteTrx.commit(reference);
       }
     }
   }
@@ -2266,36 +2048,28 @@ public boolean setOrCreateReference(int offset, PageReference pageReference) {
 
   @Override
   public void setPageReference(final long key, @NonNull final PageReference reference) {
-    referencesOrInit().put(key, reference);
+    references.put(key, reference);
   }
 
   @Override
   public Set> referenceEntrySet() {
-    return references != null ? references.entrySet() : Set.of();
+    return references.entrySet();
   }
 
   @Override
   public PageReference getPageReference(final long key) {
-    return references != null ? references.get(key) : null;
-  }
-
-  private Map referencesOrInit() {
-    var refs = references;
-    if (refs == null) {
-      refs = new ConcurrentHashMap<>();
-      references = refs;
-    }
-    return refs;
+    return references.get(key);
   }
 
   @Override
   public MemorySegment slots() {
-    return slotMemory;
+    return slottedPage;
   }
 
   @Override
   public MemorySegment deweyIds() {
-    return deweyIdMemory;
+    // DeweyIDs are inline in the slotted page heap — no separate memory
+    return null;
   }
 
   @Override
@@ -2309,8 +2083,8 @@ public int getRevision() {
   }
 
   /**
-   * Get the current version of this page frame. Used for detecting page reuse via version counter
-   * check.
+   * Get the current version of this page frame.
+   * Used for detecting page reuse via version counter check.
    *
    * @return current version number
    */
@@ -2319,22 +2093,25 @@ public int getVersion() {
   }
 
   /**
-   * Increment the version counter. Called when the page frame is reused for a different logical page.
+   * Increment the version counter.
+   * Called when the page frame is reused for a different logical page.
    */
   public void incrementVersion() {
     version.incrementAndGet();
   }
 
   /**
-   * Acquire a guard on this page (increment guard count). Pages with active guards cannot be evicted.
+   * Acquire a guard on this page (increment guard count).
+   * Pages with active guards cannot be evicted.
    */
   public void acquireGuard() {
     guardCount.incrementAndGet();
   }
 
   /**
-   * Try to acquire a guard on this page. Returns false if the page is orphaned or closed (cannot be
-   * used). This is the synchronized version that prevents race conditions with close().
+   * Try to acquire a guard on this page.
+   * Returns false if the page is orphaned or closed (cannot be used).
+   * This is the synchronized version that prevents race conditions with close().
    *
    * @return true if guard was acquired, false if page is orphaned/closed
    */
@@ -2348,9 +2125,9 @@ public synchronized boolean tryAcquireGuard() {
   }
 
   /**
-   * Release a guard on this page (decrement guard count). If the page is orphaned and this was the
-   * last guard, the page is closed. This ensures deterministic cleanup without relying on
-   * GC/finalizers.
+   * Release a guard on this page (decrement guard count).
+   * If the page is orphaned and this was the last guard, the page is closed.
+   * This ensures deterministic cleanup without relying on GC/finalizers.
    */
   public synchronized void releaseGuard() {
     guardCount.decrementAndGet();
@@ -2362,8 +2139,9 @@ public synchronized void releaseGuard() {
   }
 
   /**
-   * Mark this page as orphaned using lock-free CAS. Called when the page is removed from cache but
-   * still has active guards. The page will be closed when the last guard is released.
+   * Mark this page as orphaned using lock-free CAS.
+   * Called when the page is removed from cache but still has active guards.
+   * The page will be closed when the last guard is released.
    */
   public void markOrphaned() {
     int current;
@@ -2385,7 +2163,8 @@ public boolean isOrphaned() {
   }
 
   /**
-   * Get the current guard count. Used by ClockSweeper to check if page can be evicted.
+   * Get the current guard count.
+   * Used by ClockSweeper to check if page can be evicted.
    *
    * @return current guard count
    */
@@ -2394,11 +2173,12 @@ public int getGuardCount() {
   }
 
   /**
-   * Mark this page as recently accessed (set HOT bit). Called on every page access for clock eviction
-   * algorithm.
+   * Mark this page as recently accessed (set HOT bit).
+   * Called on every page access for clock eviction algorithm.
    * 

-   * Uses opaque memory access (no memory barriers) for maximum performance. The HOT bit is advisory -
-   * stale reads are acceptable and will at worst give a page an extra second chance during eviction.
+   * Uses opaque memory access (no memory barriers) for maximum performance.
+   * The HOT bit is advisory - stale reads are acceptable and will at worst
+   * give a page an extra second chance during eviction.
    * 

    */
   public void markAccessed() {
@@ -2443,56 +2223,48 @@ public void clearHot() {
   }
 
   /**
-   * Reset page data structures for reuse. Clears records and internal state but keeps MemorySegments
-   * allocated. Used when evicting a page to prepare frame for reuse.
+   * Reset page data structures for reuse.
+   * Clears records and internal state but keeps MemorySegments allocated.
+   * Used when evicting a page to prepare frame for reuse.
    */
   public void reset() {
     // Clear record arrays
     Arrays.fill(records, null);
-    inMemoryRecordCount = 0;
-    demotionThreshold = MIN_DEMOTION_THRESHOLD;
-    rematerializedRecordsSinceLastDemotion = 0;
-
-    // Clear offsets
-    Arrays.fill(slotOffsets, -1);
-    Arrays.fill(deweyIdOffsets, -1);
 
     // Clear slot bitmap (all slots now empty)
     Arrays.fill(slotBitmap, 0L);
-    Arrays.fill(fixedFormatBitmap, 0L);
-    Arrays.fill(fixedSlotKinds, NO_FIXED_SLOT_KIND);
 
-    // Reset free space pointers
-    slotMemoryFreeSpaceStart = 0;
-    deweyIdMemoryFreeSpaceStart = 0;
-    lastSlotIndex = -1;
-    lastDeweyIdIndex = areDeweyIDsStored
-        ? -1
-        : -1;
+    // Reset slotted page state (bitmap and heap pointers)
+    if (slottedPage != null) {
+      PageLayout.initializePage(slottedPage, recordPageKey, revision,
+          indexType.getID(), areDeweyIDsStored);
+    }
 
+    // Reset index trackers
+    lastSlotIndex = -1;
+    lastDeweyIdIndex = -1;
+    
     // Clear references
-    if (references != null) {
-      references.clear();
-    }
+    references.clear();
     addedReferences = false;
-
+    
     // Clear cached data
     bytes = null;
     hashCode = null;
-
+    
     // CRITICAL: Guard count MUST be 0 before reset
     int currentGuardCount = guardCount.get();
     if (currentGuardCount != 0) {
-      throw new IllegalStateException(String.format(
-          "CRITICAL BUG: reset() called on page with active guards! "
-              + "Page %d (%s) rev=%d guardCount=%d - this will cause guard count corruption!",
-          recordPageKey, indexType, revision, currentGuardCount));
+      throw new IllegalStateException(
+          String.format("CRITICAL BUG: reset() called on page with active guards! " +
+              "Page %d (%s) rev=%d guardCount=%d - this will cause guard count corruption!",
+              recordPageKey, indexType, revision, currentGuardCount));
     }
     hash = 0;
-
+    
     // Clear HOT bit using lock-free operation
     clearHot();
-
+    
     // NOTE: We do NOT release MemorySegments here - they stay allocated
     // The allocator's release() method is called separately if needed
   }
@@ -2504,36 +2276,22 @@ public void addReferences(final ResourceConfiguration resourceConfiguration) {
       // This is the deferred work from combineRecordPagesForModification for DIFFERENTIAL,
       // INCREMENTAL (full-dump), and SLIDING_SNAPSHOT versioning types.
       if (preservationBitmap != null && completePageRef != null) {
-        for (int wordIndex = 0; wordIndex < BITMAP_WORDS; wordIndex++) {
-          long word = preservationBitmap[wordIndex];
-          int baseSlot = wordIndex << 6;
-          while (word != 0) {
-            int bit = Long.numberOfTrailingZeros(word);
-            int slotIndex = baseSlot + bit;
-
-            // Preserve only when the slot is still absent from the modified page.
-            // This keeps write-intent data authoritative and avoids rematerialization churn.
-            if (records[slotIndex] == null && !hasSlot(slotIndex)) {
-              MemorySegment slotData = completePageRef.getSlot(slotIndex);
-              if (slotData != null) {
-                setSlot(slotData, slotIndex);
-                final NodeKind fixedNodeKind = completePageRef.getFixedSlotNodeKind(slotIndex);
-                if (fixedNodeKind != null) {
-                  markSlotAsFixedFormat(slotIndex, fixedNodeKind);
-                } else {
-                  markSlotAsCompactFormat(slotIndex);
-                }
-              }
-
-              if (areDeweyIDsStored) {
-                MemorySegment deweyId = completePageRef.getDeweyId(slotIndex);
-                if (deweyId != null) {
-                  setDeweyId(deweyId, slotIndex);
-                }
+        for (int i = 0; i < Constants.NDP_NODE_COUNT; i++) {
+          // Check if slot needs preservation AND wasn't modified (neither in records[] nor in slot data)
+          boolean needsPreservation = (preservationBitmap[i >>> 6] & (1L << (i & 63))) != 0;
+          if (needsPreservation && records[i] == null && getSlot(i) == null) {
+            // Copy slot from completePage, preserving nodeKindId
+            MemorySegment slotData = completePageRef.getSlot(i);
+            if (slotData != null) {
+              setSlotWithNodeKind(slotData, i, completePageRef.getSlotNodeKindId(i));
+            }
+            // Copy deweyId too if stored
+            if (areDeweyIDsStored) {
+              MemorySegment deweyId = completePageRef.getDeweyId(i);
+              if (deweyId != null) {
+                setDeweyId(deweyId, i);
               }
             }
-
-            word &= word - 1;
           }
         }
       }
@@ -2542,11 +2300,8 @@ public void addReferences(final ResourceConfiguration resourceConfiguration) {
         processEntries(resourceConfiguration, records);
         for (int i = 0; i < records.length; i++) {
           final DataRecord record = records[i];
-          if (record != null && record.getNodeKey() != 0) {
-            final byte[] deweyBytes = record.getDeweyIDAsBytes();
-            if (deweyBytes != null) {
-              setDeweyId(deweyBytes, i);
-            }
+          if (record != null && record.getDeweyID() != null && record.getNodeKey() != 0) {
+            setDeweyId(record.getDeweyID().toBytes(), i);
           }
         }
       } else {
@@ -2567,10 +2322,37 @@ private void processEntries(final ResourceConfiguration resourceConfiguration, f
       // This eliminates ~N allocations where N = number of non-null records.
       var reusableOut = new MemorySegmentBytesOut(tempArena, 256);
 
-      for (final DataRecord record : records) {
+      for (int i = 0; i < records.length; i++) {
+        final DataRecord record = records[i];
         if (record == null) {
+          // Write singletons (FlyweightNode.isWriteSingleton()) are never stored in records[] —
+          // their data is already serialized to the slotted page heap via serializeToHeap() in setRecord().
           continue;
         }
+        if (record instanceof FlyweightNode fn) {
+          if (fn.isBound()) {
+            // Record data is already in the heap via serializeToHeap() — skip serialization.
+            // However, DeweyIDs are stored separately and may have been updated after binding
+            // (e.g., by computeNewDeweyIDs during moveSubtreeToFirstChild). Since records[i]
+            // is about to be nulled, persist the DeweyID to the heap now.
+            if (areDeweyIDsStored && fn.getDeweyID() != null && fn.getNodeKey() != 0) {
+              final byte[] deweyIdBytes = fn.getDeweyIDAsBytes();
+              if (deweyIdBytes != null && deweyIdBytes.length > 0) {
+                setDeweyIdToHeap(MemorySegment.ofArray(deweyIdBytes), i);
+              }
+            }
+            records[i] = null;
+            continue;
+          }
+          // Unbound flyweight (e.g., value mutation caused unbind): re-serialize to slotted page heap.
+          if (slottedPage != null) {
+            final long nodeKey = record.getNodeKey();
+            final int offset = StorageEngineReader.recordPageOffset(nodeKey);
+            serializeToHeap(fn, nodeKey, offset);
+            records[i] = null;
+            continue;
+          }
+        }
         final var recordID = record.getNodeKey();
         final var offset = StorageEngineReader.recordPageOffset(recordID);
 
@@ -2588,78 +2370,21 @@ private void processEntries(final ResourceConfiguration resourceConfiguration, f
 
           final var reference = new PageReference();
           reference.setPage(new OverflowPage(persistentBuffer));
-          referencesOrInit().put(recordID, reference);
+          references.put(recordID, reference);
         } else {
-          // Normal record: setSlot copies data to slotMemory, so temp buffer is fine
+          // Normal record: setSlot copies data to slotted page heap (slotted page heap)
           setSlot(buffer, offset);
-          markSlotAsCompactFormat(offset);
         }
+        // Clear record reference after serialization — snapshot isolation.
+        // Data is now in slotMemory/slottedPage; prevents cross-transaction aliasing.
+        records[i] = null;
       }
     } // Confined arena automatically closes here, freeing all temporary buffers
   }
 
-  void compactFixedSlotsForCommit(final ResourceConfiguration resourceConfiguration) {
-    // Quick exit: no fixed-format slots → nothing to compact.
-    boolean hasFixedSlots = false;
-    for (int w = 0; w < BITMAP_WORDS; w++) {
-      if (fixedFormatBitmap[w] != 0) {
-        hasFixedSlots = true;
-        break;
-      }
-    }
-    if (!hasFixedSlots) {
-      return;
-    }
-
-    // In-place compaction: compact format is always <= fixed format in size,
-    // so we overwrite each fixed slot at its current offset. No buffer allocation needed.
-    // Any gaps left by shrunk slots are eliminated by downstream compactLengthPrefixedRegion().
-    final MemorySegmentBytesOut compactBuffer = COMPACT_BUFFER.get();
-
-    for (int wordIndex = 0; wordIndex < BITMAP_WORDS; wordIndex++) {
-      long word = fixedFormatBitmap[wordIndex];
-      final int baseSlot = wordIndex << 6;
-      while (word != 0) {
-        final int bit = Long.numberOfTrailingZeros(word);
-        final int slotIndex = baseSlot + bit;
-        final long nodeKey = (recordPageKey << Constants.NDP_NODE_COUNT_EXPONENT) + slotIndex;
-
-        final NodeKind nodeKind = getFixedSlotNodeKind(slotIndex);
-        final int slotOffset = slotOffsets[slotIndex];
-        final long slotDataOffset = slotOffset + INT_SIZE;
-
-        if (nodeKind == null) {
-          throw new IllegalStateException("Missing fixed-slot metadata for node key " + nodeKey);
-        }
-
-        // Direct byte-level transformation: fixed → compact without materializing a DataRecord.
-        // Uses base-offset into slotMemory to avoid asSlice() allocation per slot.
-        compactBuffer.clear();
-        FixedToCompactTransformer.transform(nodeKind, nodeKey, slotMemory, slotDataOffset, resourceConfiguration,
-            compactBuffer);
-        final MemorySegment compactBytes = compactBuffer.getDestination();
-        final int compactSize = (int) compactBytes.byteSize();
-        if (compactSize > PageConstants.MAX_RECORD_SIZE) {
-          throw new IllegalStateException("Compacted record exceeds max size for node key " + nodeKey);
-        }
-
-        // Overwrite in-place: compact bytes fit within the fixed slot's footprint.
-        // Offset unchanged — only the length prefix and data bytes are rewritten.
-        slotMemory.set(JAVA_INT_UNALIGNED, slotOffset, compactSize);
-        MemorySegment.copy(compactBytes, 0, slotMemory, slotOffset + INT_SIZE, compactSize);
-
-        word &= word - 1;
-      }
-    }
-
-    // Clear fixed-format tracking — all slots are now compact format.
-    Arrays.fill(fixedFormatBitmap, 0L);
-    Arrays.fill(fixedSlotKinds, NO_FIXED_SLOT_KIND);
-  }
-
   /**
-   * Build FSST symbol table from all string values in this page. This should be called before
-   * serialization to enable page-level compression.
+   * Build FSST symbol table from all string values in this page.
+   * This should be called before serialization to enable page-level compression.
    *
    * @param resourceConfig the resource configuration
    * @return true if FSST compression is enabled and symbol table was built
@@ -2669,57 +2394,58 @@ public boolean buildFsstSymbolTable(ResourceConfiguration resourceConfig) {
       return false;
     }
 
+    final int stringValueId = NodeKind.STRING_VALUE.getId();
+    final int objectStringValueId = NodeKind.OBJECT_STRING_VALUE.getId();
+
     // Collect all string values from StringNode and ObjectStringNode
     java.util.ArrayList stringSamples = new java.util.ArrayList<>();
 
+    // Scan records[] for non-FlyweightNode string records (legacy path)
     for (final DataRecord record : records) {
       if (record == null) {
         continue;
       }
       if (record instanceof StringNode stringNode) {
-        addStringSample(stringSamples, stringNode.getRawValueWithoutDecompression());
+        byte[] value = stringNode.getRawValueWithoutDecompression();
+        if (value != null && value.length > 0) {
+          stringSamples.add(value);
+        }
       } else if (record instanceof ObjectStringNode objectStringNode) {
-        addStringSample(stringSamples, objectStringNode.getRawValueWithoutDecompression());
-      } else if (record instanceof TextNode textNode) {
-        addStringSample(stringSamples, textNode.getRawValueWithoutDecompression());
-      } else if (record instanceof CommentNode commentNode) {
-        addStringSample(stringSamples, commentNode.getRawValueWithoutDecompression());
-      } else if (record instanceof PINode piNode) {
-        addStringSample(stringSamples, piNode.getRawValueWithoutDecompression());
-      } else if (record instanceof AttributeNode attrNode) {
-        addStringSample(stringSamples, attrNode.getRawValueWithoutDecompression());
+        byte[] value = objectStringNode.getRawValueWithoutDecompression();
+        if (value != null && value.length > 0) {
+          stringSamples.add(value);
+        }
       }
     }
 
-    // Include string values only present in slot memory (demoted records).
-    // This is commit-path work and preserves FSST sample completeness.
-    // Fixed-format slots are already compacted before this method runs.
-    for (int i = 0; i < Constants.NDP_NODE_COUNT; i++) {
-      if (records[i] != null) {
-        continue;
-      }
-
-      final MemorySegment slot = getSlot(i);
-      if (slot == null) {
-        continue;
-      }
-
-      final long nodeKey = (recordPageKey << Constants.NDP_NODE_COUNT_EXPONENT) + i;
-      final DataRecord record = resourceConfig.recordPersister.deserialize(new MemorySegmentBytesIn(slot), nodeKey,
-          getDeweyIdAsByteArray(i), resourceConfig);
-
-      if (record instanceof StringNode stringNode) {
-        addStringSample(stringSamples, stringNode.getRawValueWithoutDecompression());
-      } else if (record instanceof ObjectStringNode objectStringNode) {
-        addStringSample(stringSamples, objectStringNode.getRawValueWithoutDecompression());
-      } else if (record instanceof TextNode textNode) {
-        addStringSample(stringSamples, textNode.getRawValueWithoutDecompression());
-      } else if (record instanceof CommentNode commentNode) {
-        addStringSample(stringSamples, commentNode.getRawValueWithoutDecompression());
-      } else if (record instanceof PINode piNode) {
-        addStringSample(stringSamples, piNode.getRawValueWithoutDecompression());
-      } else if (record instanceof AttributeNode attrNode) {
-        addStringSample(stringSamples, attrNode.getRawValueWithoutDecompression());
+    // Scan slotted page for FlyweightNode strings (zero records[] path)
+    if (slottedPage != null) {
+      for (int i = 0; i < Constants.NDP_NODE_COUNT; i++) {
+        if (records[i] != null) continue; // Already scanned above
+        if (!PageLayout.isSlotPopulated(slottedPage, i)) continue;
+        final int nodeKindId = PageLayout.getDirNodeKindId(slottedPage, i);
+        if (nodeKindId == stringValueId || nodeKindId == objectStringValueId) {
+          final int heapOff = PageLayout.getDirHeapOffset(slottedPage, i);
+          final long recordBase = PageLayout.heapAbsoluteOffset(heapOff);
+          final long nodeKey = (recordPageKey << Constants.NDP_NODE_COUNT_EXPONENT) + i;
+          if (nodeKindId == stringValueId) {
+            fsstStringFlyweight.bind(slottedPage, recordBase, nodeKey, i);
+            try {
+              byte[] value = fsstStringFlyweight.getRawValueWithoutDecompression();
+              if (value != null && value.length > 0) stringSamples.add(value);
+            } finally {
+              fsstStringFlyweight.clearBinding();
+            }
+          } else {
+            fsstObjStringFlyweight.bind(slottedPage, recordBase, nodeKey, i);
+            try {
+              byte[] value = fsstObjStringFlyweight.getRawValueWithoutDecompression();
+              if (value != null && value.length > 0) stringSamples.add(value);
+            } finally {
+              fsstObjStringFlyweight.clearBinding();
+            }
+          }
+        }
       }
     }
 
@@ -2732,7 +2458,6 @@ public boolean buildFsstSymbolTable(ResourceConfiguration resourceConfig) {
       if (candidateTable != null && candidateTable.length > 0
           && FSSTCompressor.isCompressionBeneficial(stringSamples, candidateTable)) {
         this.fsstSymbolTable = candidateTable;
-        this.parsedFsstSymbols = FSSTCompressor.parseSymbolTable(candidateTable);
         return true;
       }
     }
@@ -2740,37 +2465,29 @@ public boolean buildFsstSymbolTable(ResourceConfiguration resourceConfig) {
     return false;
   }
 
-  private static void addStringSample(java.util.ArrayList samples, byte[] value) {
-    if (value != null && value.length > 0) {
-      samples.add(value);
-    }
-  }
-
   /**
-   * Compress all string values in the page using the pre-built FSST symbol table. This modifies the
-   * string nodes in place to use compressed values. Must be called after buildFsstSymbolTable().
+   * Compress all string values in the page using the pre-built FSST symbol table.
+   * This modifies the string nodes in place to use compressed values.
+   * Must be called after buildFsstSymbolTable().
    */
   public void compressStringValues() {
     if (fsstSymbolTable == null || fsstSymbolTable.length == 0) {
       return;
     }
 
-    // Use pre-parsed symbols to avoid re-parsing for every string node
-    final byte[][] symbols = parsedFsstSymbols;
-    if (symbols == null || symbols.length == 0) {
-      return;
-    }
+    final int stringValueId = NodeKind.STRING_VALUE.getId();
+    final int objectStringValueId = NodeKind.OBJECT_STRING_VALUE.getId();
 
+    // Compress records[] strings (legacy path)
     for (final DataRecord record : records) {
       if (record == null) {
         continue;
       }
       if (record instanceof StringNode stringNode) {
         if (!stringNode.isCompressed()) {
-          final byte[] originalValue = stringNode.getRawValueWithoutDecompression();
+          byte[] originalValue = stringNode.getRawValueWithoutDecompression();
           if (originalValue != null && originalValue.length > 0) {
-            final byte[] compressedValue = FSSTCompressor.encode(originalValue, symbols);
-            // Only use compressed value if it's actually smaller
+            byte[] compressedValue = FSSTCompressor.encode(originalValue, fsstSymbolTable);
             if (compressedValue.length < originalValue.length) {
               stringNode.setRawValue(compressedValue, true, fsstSymbolTable);
             }
@@ -2778,10 +2495,9 @@ public void compressStringValues() {
         }
       } else if (record instanceof ObjectStringNode objectStringNode) {
         if (!objectStringNode.isCompressed()) {
-          final byte[] originalValue = objectStringNode.getRawValueWithoutDecompression();
+          byte[] originalValue = objectStringNode.getRawValueWithoutDecompression();
           if (originalValue != null && originalValue.length > 0) {
-            final byte[] compressedValue = FSSTCompressor.encode(originalValue, symbols);
-            // Only use compressed value if it's actually smaller
+            byte[] compressedValue = FSSTCompressor.encode(originalValue, fsstSymbolTable);
             if (compressedValue.length < originalValue.length) {
               objectStringNode.setRawValue(compressedValue, true, fsstSymbolTable);
             }
@@ -2789,27 +2505,71 @@ public void compressStringValues() {
         }
       }
     }
+
+    // Compress slotted page strings (zero records[] path)
+    if (slottedPage != null) {
+      for (int i = 0; i < Constants.NDP_NODE_COUNT; i++) {
+        if (records[i] != null) continue; // Already handled above
+        if (!PageLayout.isSlotPopulated(slottedPage, i)) continue;
+        final int nodeKindId = PageLayout.getDirNodeKindId(slottedPage, i);
+        if (nodeKindId != stringValueId && nodeKindId != objectStringValueId) continue;
+
+        final int heapOff = PageLayout.getDirHeapOffset(slottedPage, i);
+        final long recordBase = PageLayout.heapAbsoluteOffset(heapOff);
+        final long nodeKey = (recordPageKey << Constants.NDP_NODE_COUNT_EXPONENT) + i;
+
+        if (nodeKindId == stringValueId) {
+          fsstStringFlyweight.bind(slottedPage, recordBase, nodeKey, i);
+          fsstStringFlyweight.setOwnerPage(this); // Enable write-through
+          try {
+            byte[] originalValue = fsstStringFlyweight.getRawValueWithoutDecompression();
+            if (originalValue != null && originalValue.length > 0 && !fsstStringFlyweight.isCompressed()) {
+              byte[] compressed = FSSTCompressor.encode(originalValue, fsstSymbolTable);
+              if (compressed.length < originalValue.length) {
+                fsstStringFlyweight.setRawValue(compressed, true, fsstSymbolTable);
+              }
+            }
+          } finally {
+            fsstStringFlyweight.setOwnerPage(null);
+            fsstStringFlyweight.clearBinding();
+          }
+        } else {
+          fsstObjStringFlyweight.bind(slottedPage, recordBase, nodeKey, i);
+          fsstObjStringFlyweight.setOwnerPage(this); // Enable write-through
+          try {
+            byte[] originalValue = fsstObjStringFlyweight.getRawValueWithoutDecompression();
+            if (originalValue != null && originalValue.length > 0 && !fsstObjStringFlyweight.isCompressed()) {
+              byte[] compressed = FSSTCompressor.encode(originalValue, fsstSymbolTable);
+              if (compressed.length < originalValue.length) {
+                fsstObjStringFlyweight.setRawValue(compressed, true, fsstSymbolTable);
+              }
+            }
+          } finally {
+            fsstObjStringFlyweight.setOwnerPage(null);
+            fsstObjStringFlyweight.clearBinding();
+          }
+        }
+      }
+    }
   }
 
   /**
-   * Set the FSST symbol table on all string nodes after deserialization. This allows nodes to use
-   * lazy decompression.
+   * Set the FSST symbol table on all string nodes after deserialization.
+   * This allows nodes to use lazy decompression.
    */
   public void propagateFsstSymbolTableToNodes() {
     if (fsstSymbolTable == null || fsstSymbolTable.length == 0) {
       return;
     }
 
-    final byte[][] parsed = parsedFsstSymbols;
-
     for (final DataRecord record : records) {
       if (record == null) {
         continue;
       }
       if (record instanceof StringNode stringNode) {
-        stringNode.setFsstSymbolTable(fsstSymbolTable, parsed);
+        stringNode.setFsstSymbolTable(fsstSymbolTable);
       } else if (record instanceof ObjectStringNode objectStringNode) {
-        objectStringNode.setFsstSymbolTable(fsstSymbolTable, parsed);
+        objectStringNode.setFsstSymbolTable(fsstSymbolTable);
       }
     }
   }
@@ -2820,51 +2580,48 @@ public void propagateFsstSymbolTableToNodes() {
    * @param slotNumber the slot number in the page (0 to NDP_NODE_COUNT-1)
    * @param value the raw string value bytes
    */
-  private record StringValueEntry(int slotNumber, byte[] value) {
-  }
+  private record StringValueEntry(int slotNumber, byte[] value) {}
 
   /**
-   * Collect string values into columnar storage for better compression. Groups all string data
-   * contiguously in stringValueMemory, which enables better FSST compression patterns and more
-   * efficient storage.
+   * Collect string values into columnar storage for better compression.
+   * Groups all string data contiguously in stringValueMemory, which enables
+   * better FSST compression patterns and more efficient storage.
    * 
-   * 

-   * This should be called before serialization when columnar storage is desired. The columnar layout
-   * stores: [length1:4][data1:N][length2:4][data2:M]... with stringValueOffsets pointing to each
-   * entry's start.
+   * 
This should be called before serialization when columnar storage is desired.
+   * The columnar layout stores: [length1:4][data1:N][length2:4][data2:M]...
+   * with stringValueOffsets pointing to each entry's start.
    * 
-   * 

-   * Invariants maintained:
+   * 
Invariants maintained:
    * 
    
-   * 
  • P4: All offsets are valid: 0 ≤ offset < stringValueMemory.byteSize()
    • 
-   * 
  • No overlapping entries
    • 
-   * 
  • Sequential layout with no gaps
    • 
+   *   
  • P4: All offsets are valid: 0 ≤ offset < stringValueMemory.byteSize()
    • 
+   *   
  • No overlapping entries
    • 
+   *   
  • Sequential layout with no gaps
    • 
    * 

    */
   public void collectStringsForColumnarStorage() {
     java.util.List entries = new java.util.ArrayList<>();
     int totalSize = 0;
-
+    
     for (int i = 0; i < records.length; i++) {
       DataRecord record = records[i];
       byte[] value = null;
-
+      
       if (record instanceof StringNode sn) {
         value = sn.getRawValueWithoutDecompression();
       } else if (record instanceof ObjectStringNode osn) {
         value = osn.getRawValueWithoutDecompression();
       }
-
+      
       if (value != null && value.length > 0) {
         entries.add(new StringValueEntry(i, value));
         totalSize += INT_SIZE + value.length; // 4 bytes length prefix + data
       }
     }
-
+    
     if (entries.isEmpty()) {
       return;
     }
-
+    
     // Allocate columnar segment if needed
     if (stringValueMemory == null || stringValueMemory.byteSize() < totalSize) {
       if (stringValueMemory != null && !externallyAllocatedMemory) {
@@ -2872,30 +2629,30 @@ public void collectStringsForColumnarStorage() {
       }
       stringValueMemory = segmentAllocator.allocate(totalSize);
     }
-
+    
     // Store all string values contiguously
     int offset = 0;
     for (StringValueEntry entry : entries) {
       // Validate offset bounds (P4 invariant)
       if (offset + INT_SIZE + entry.value.length > stringValueMemory.byteSize()) {
-        throw new IllegalStateException(
-            String.format("Columnar storage overflow: offset=%d, entrySize=%d, memorySize=%d", offset,
-                INT_SIZE + entry.value.length, stringValueMemory.byteSize()));
+        throw new IllegalStateException(String.format(
+            "Columnar storage overflow: offset=%d, entrySize=%d, memorySize=%d",
+            offset, INT_SIZE + entry.value.length, stringValueMemory.byteSize()));
       }
-
+      
       stringValueOffsets[entry.slotNumber] = offset;
-
+      
       // Write length prefix
       stringValueMemory.set(java.lang.foreign.ValueLayout.JAVA_INT, offset, entry.value.length);
-
+      
       // Write data using bulk copy
-      MemorySegment.copy(entry.value, 0, stringValueMemory, java.lang.foreign.ValueLayout.JAVA_BYTE, offset + INT_SIZE,
-          entry.value.length);
-
+      MemorySegment.copy(entry.value, 0, stringValueMemory,
+          java.lang.foreign.ValueLayout.JAVA_BYTE, offset + INT_SIZE, entry.value.length);
+      
       offset += INT_SIZE + entry.value.length;
       lastStringValueIndex = Math.max(lastStringValueIndex, entry.slotNumber);
     }
-
+    
     stringValueMemoryFreeSpaceStart = offset;
   }
 
diff --git a/bundles/sirix-core/src/main/java/io/sirix/page/NodeFieldLayout.java b/bundles/sirix-core/src/main/java/io/sirix/page/NodeFieldLayout.java
new file mode 100644
index 000000000..872887bd0
--- /dev/null
+++ b/bundles/sirix-core/src/main/java/io/sirix/page/NodeFieldLayout.java
@@ -0,0 +1,337 @@
+package io.sirix.page;
+
+import io.sirix.node.NodeKind;
+
+/**
+ * Defines the per-record offset table layout for each {@link NodeKind}.
+ *
+ * 
Each record in the heap has an offset table with one byte per field,
+ * enabling O(1) access to any field without parsing preceding varints.
+ * This class defines the field count and field index constants for each NodeKind.
+ *
+ * 
Offset Table Format

+ * 
+ * [nodeKind: 1 byte]
+ * [fieldOffsetTable: fieldCount × 1 byte]
+ * [data region: varint fields + hash + optional payload]
+ * 

+ *
+ * 
ALL fields are always present in the slotted page format, including hash (0 when unused)
+ * and childCount/descendantCount (0 when unused). This eliminates conditional field logic
+ * and makes the offset table size fixed per NodeKind.
+ */
+public final class NodeFieldLayout {
+
+  private NodeFieldLayout() {
+    throw new AssertionError("Utility class");
+  }
+
+  /** Fixed width of hash field in bytes (always 8). */
+  public static final int HASH_WIDTH = Long.BYTES;
+
+  // ==================== OBJECT NODE (10 fields) ====================
+
+  /** Total field count for OBJECT nodes. */
+  public static final int OBJECT_FIELD_COUNT = 10;
+
+  public static final int OBJECT_PARENT_KEY = 0;
+  public static final int OBJECT_RIGHT_SIB_KEY = 1;
+  public static final int OBJECT_LEFT_SIB_KEY = 2;
+  public static final int OBJECT_FIRST_CHILD_KEY = 3;
+  public static final int OBJECT_LAST_CHILD_KEY = 4;
+  public static final int OBJECT_PREV_REVISION = 5;
+  public static final int OBJECT_LAST_MOD_REVISION = 6;
+  public static final int OBJECT_HASH = 7;
+  public static final int OBJECT_CHILD_COUNT = 8;
+  public static final int OBJECT_DESCENDANT_COUNT = 9;
+
+  // ==================== ARRAY NODE (11 fields) ====================
+
+  /** Total field count for ARRAY nodes. */
+  public static final int ARRAY_FIELD_COUNT = 11;
+
+  public static final int ARRAY_PARENT_KEY = 0;
+  public static final int ARRAY_RIGHT_SIB_KEY = 1;
+  public static final int ARRAY_LEFT_SIB_KEY = 2;
+  public static final int ARRAY_FIRST_CHILD_KEY = 3;
+  public static final int ARRAY_LAST_CHILD_KEY = 4;
+  public static final int ARRAY_PATH_NODE_KEY = 5;
+  public static final int ARRAY_PREV_REVISION = 6;
+  public static final int ARRAY_LAST_MOD_REVISION = 7;
+  public static final int ARRAY_HASH = 8;
+  public static final int ARRAY_CHILD_COUNT = 9;
+  public static final int ARRAY_DESCENDANT_COUNT = 10;
+
+  // ==================== OBJECT_KEY NODE (10 fields) ====================
+
+  /** Total field count for OBJECT_KEY nodes. */
+  public static final int OBJECT_KEY_FIELD_COUNT = 10;
+
+  public static final int OBJKEY_PARENT_KEY = 0;
+  public static final int OBJKEY_RIGHT_SIB_KEY = 1;
+  public static final int OBJKEY_LEFT_SIB_KEY = 2;
+  public static final int OBJKEY_FIRST_CHILD_KEY = 3;
+  public static final int OBJKEY_NAME_KEY = 4;
+  public static final int OBJKEY_PATH_NODE_KEY = 5;
+  public static final int OBJKEY_PREV_REVISION = 6;
+  public static final int OBJKEY_LAST_MOD_REVISION = 7;
+  public static final int OBJKEY_HASH = 8;
+  public static final int OBJKEY_DESCENDANT_COUNT = 9;
+
+  // ==================== STRING_VALUE NODE (7 fields + payload) ====================
+
+  /** Total field count for STRING_VALUE nodes (excluding payload). */
+  public static final int STRING_VALUE_FIELD_COUNT = 6;
+
+  public static final int STRVAL_PARENT_KEY = 0;
+  public static final int STRVAL_RIGHT_SIB_KEY = 1;
+  public static final int STRVAL_LEFT_SIB_KEY = 2;
+  public static final int STRVAL_PREV_REVISION = 3;
+  public static final int STRVAL_LAST_MOD_REVISION = 4;
+  /** Points to the start of [isCompressed:1][valueLength:varint][value:bytes]. */
+  public static final int STRVAL_PAYLOAD = 5;
+
+  // ==================== NUMBER_VALUE NODE (7 fields + payload) ====================
+
+  /** Total field count for NUMBER_VALUE nodes (excluding payload). */
+  public static final int NUMBER_VALUE_FIELD_COUNT = 6;
+
+  public static final int NUMVAL_PARENT_KEY = 0;
+  public static final int NUMVAL_RIGHT_SIB_KEY = 1;
+  public static final int NUMVAL_LEFT_SIB_KEY = 2;
+  public static final int NUMVAL_PREV_REVISION = 3;
+  public static final int NUMVAL_LAST_MOD_REVISION = 4;
+  /** Points to the start of [numberType:1][numberData:variable]. */
+  public static final int NUMVAL_PAYLOAD = 5;
+
+  // ==================== BOOLEAN_VALUE NODE (7 fields) ====================
+
+  /** Total field count for BOOLEAN_VALUE nodes. */
+  public static final int BOOLEAN_VALUE_FIELD_COUNT = 6;
+
+  public static final int BOOLVAL_PARENT_KEY = 0;
+  public static final int BOOLVAL_RIGHT_SIB_KEY = 1;
+  public static final int BOOLVAL_LEFT_SIB_KEY = 2;
+  public static final int BOOLVAL_PREV_REVISION = 3;
+  public static final int BOOLVAL_LAST_MOD_REVISION = 4;
+  public static final int BOOLVAL_VALUE = 5;
+
+  // ==================== NULL_VALUE NODE (6 fields) ====================
+
+  /** Total field count for NULL_VALUE nodes. */
+  public static final int NULL_VALUE_FIELD_COUNT = 5;
+
+  public static final int NULLVAL_PARENT_KEY = 0;
+  public static final int NULLVAL_RIGHT_SIB_KEY = 1;
+  public static final int NULLVAL_LEFT_SIB_KEY = 2;
+  public static final int NULLVAL_PREV_REVISION = 3;
+  public static final int NULLVAL_LAST_MOD_REVISION = 4;
+
+  // ==================== OBJECT_STRING_VALUE NODE (5 fields + payload) ====================
+
+  /** Total field count for OBJECT_STRING_VALUE nodes (excluding payload). */
+  public static final int OBJECT_STRING_VALUE_FIELD_COUNT = 4;
+
+  public static final int OBJSTRVAL_PARENT_KEY = 0;
+  public static final int OBJSTRVAL_PREV_REVISION = 1;
+  public static final int OBJSTRVAL_LAST_MOD_REVISION = 2;
+  /** Points to the start of [isCompressed:1][valueLength:varint][value:bytes]. */
+  public static final int OBJSTRVAL_PAYLOAD = 3;
+
+  // ==================== OBJECT_NUMBER_VALUE NODE (5 fields + payload) ====================
+
+  /** Total field count for OBJECT_NUMBER_VALUE nodes (excluding payload). */
+  public static final int OBJECT_NUMBER_VALUE_FIELD_COUNT = 4;
+
+  public static final int OBJNUMVAL_PARENT_KEY = 0;
+  public static final int OBJNUMVAL_PREV_REVISION = 1;
+  public static final int OBJNUMVAL_LAST_MOD_REVISION = 2;
+  /** Points to the start of [numberType:1][numberData:variable]. */
+  public static final int OBJNUMVAL_PAYLOAD = 3;
+
+  // ==================== OBJECT_BOOLEAN_VALUE NODE (5 fields) ====================
+
+  /** Total field count for OBJECT_BOOLEAN_VALUE nodes. */
+  public static final int OBJECT_BOOLEAN_VALUE_FIELD_COUNT = 4;
+
+  public static final int OBJBOOLVAL_PARENT_KEY = 0;
+  public static final int OBJBOOLVAL_PREV_REVISION = 1;
+  public static final int OBJBOOLVAL_LAST_MOD_REVISION = 2;
+  public static final int OBJBOOLVAL_VALUE = 3;
+
+  // ==================== OBJECT_NULL_VALUE NODE (4 fields) ====================
+
+  /** Total field count for OBJECT_NULL_VALUE nodes. */
+  public static final int OBJECT_NULL_VALUE_FIELD_COUNT = 3;
+
+  public static final int OBJNULLVAL_PARENT_KEY = 0;
+  public static final int OBJNULLVAL_PREV_REVISION = 1;
+  public static final int OBJNULLVAL_LAST_MOD_REVISION = 2;
+
+  // ==================== JSON_DOCUMENT_ROOT (7 fields) ====================
+
+  /** Total field count for JSON_DOCUMENT_ROOT nodes. */
+  public static final int JSON_DOCUMENT_ROOT_FIELD_COUNT = 7;
+
+  public static final int JDOCROOT_FIRST_CHILD_KEY = 0;
+  public static final int JDOCROOT_LAST_CHILD_KEY = 1;
+  public static final int JDOCROOT_CHILD_COUNT = 2;
+  public static final int JDOCROOT_DESCENDANT_COUNT = 3;
+  public static final int JDOCROOT_PREV_REVISION = 4;
+  public static final int JDOCROOT_LAST_MOD_REVISION = 5;
+  public static final int JDOCROOT_HASH = 6;
+
+  // ==================== XML ELEMENT NODE (15 fields + payload) ====================
+
+  /** Total field count for ELEMENT nodes (excluding attr/ns payload). */
+  public static final int ELEMENT_FIELD_COUNT = 15;
+
+  public static final int ELEM_PARENT_KEY = 0;
+  public static final int ELEM_RIGHT_SIB_KEY = 1;
+  public static final int ELEM_LEFT_SIB_KEY = 2;
+  public static final int ELEM_FIRST_CHILD_KEY = 3;
+  public static final int ELEM_LAST_CHILD_KEY = 4;
+  public static final int ELEM_PATH_NODE_KEY = 5;
+  public static final int ELEM_PREFIX_KEY = 6;
+  public static final int ELEM_LOCAL_NAME_KEY = 7;
+  public static final int ELEM_URI_KEY = 8;
+  public static final int ELEM_PREV_REVISION = 9;
+  public static final int ELEM_LAST_MOD_REVISION = 10;
+  public static final int ELEM_HASH = 11;
+  public static final int ELEM_CHILD_COUNT = 12;
+  public static final int ELEM_DESCENDANT_COUNT = 13;
+  /** Points to [attrCount:varint][attrKeys:delta...][nsCount:varint][nsKeys:delta...]. */
+  public static final int ELEM_PAYLOAD = 14;
+
+  // ==================== XML ATTRIBUTE NODE (9 fields + payload) ====================
+
+  /** Total field count for ATTRIBUTE nodes (excluding value payload). */
+  public static final int ATTRIBUTE_FIELD_COUNT = 8;
+
+  public static final int ATTR_PARENT_KEY = 0;
+  public static final int ATTR_PATH_NODE_KEY = 1;
+  public static final int ATTR_PREFIX_KEY = 2;
+  public static final int ATTR_LOCAL_NAME_KEY = 3;
+  public static final int ATTR_URI_KEY = 4;
+  public static final int ATTR_PREV_REVISION = 5;
+  public static final int ATTR_LAST_MOD_REVISION = 6;
+  /** Points to [isCompressed:1][valueLength:varint][value:bytes]. */
+  public static final int ATTR_PAYLOAD = 7;
+
+  // ==================== XML TEXT NODE (7 fields + payload) ====================
+
+  /** Total field count for TEXT nodes (excluding value payload). */
+  public static final int TEXT_FIELD_COUNT = 6;
+
+  public static final int TEXT_PARENT_KEY = 0;
+  public static final int TEXT_RIGHT_SIB_KEY = 1;
+  public static final int TEXT_LEFT_SIB_KEY = 2;
+  public static final int TEXT_PREV_REVISION = 3;
+  public static final int TEXT_LAST_MOD_REVISION = 4;
+  /** Points to [isCompressed:1][valueLength:varint][value:bytes]. */
+  public static final int TEXT_PAYLOAD = 5;
+
+  // ==================== XML COMMENT NODE (7 fields + payload) ====================
+
+  /** Total field count for COMMENT nodes (excluding value payload). */
+  public static final int COMMENT_FIELD_COUNT = 6;
+
+  public static final int COMMENT_PARENT_KEY = 0;
+  public static final int COMMENT_RIGHT_SIB_KEY = 1;
+  public static final int COMMENT_LEFT_SIB_KEY = 2;
+  public static final int COMMENT_PREV_REVISION = 3;
+  public static final int COMMENT_LAST_MOD_REVISION = 4;
+  /** Points to [isCompressed:1][valueLength:varint][value:bytes]. */
+  public static final int COMMENT_PAYLOAD = 5;
+
+  // ==================== XML PI NODE (15 fields + payload) ====================
+
+  /** Total field count for PROCESSING_INSTRUCTION nodes (excluding value payload). */
+  public static final int PI_FIELD_COUNT = 14;
+
+  public static final int PI_PARENT_KEY = 0;
+  public static final int PI_RIGHT_SIB_KEY = 1;
+  public static final int PI_LEFT_SIB_KEY = 2;
+  public static final int PI_FIRST_CHILD_KEY = 3;
+  public static final int PI_LAST_CHILD_KEY = 4;
+  public static final int PI_PATH_NODE_KEY = 5;
+  public static final int PI_PREFIX_KEY = 6;
+  public static final int PI_LOCAL_NAME_KEY = 7;
+  public static final int PI_URI_KEY = 8;
+  public static final int PI_PREV_REVISION = 9;
+  public static final int PI_LAST_MOD_REVISION = 10;
+  public static final int PI_CHILD_COUNT = 11;
+  public static final int PI_DESCENDANT_COUNT = 12;
+  /** Points to [isCompressed:1][valueLength:varint][value:bytes]. */
+  public static final int PI_PAYLOAD = 13;
+
+  // ==================== XML NAMESPACE NODE (8 fields) ====================
+
+  /** Total field count for NAMESPACE nodes. */
+  public static final int NAMESPACE_FIELD_COUNT = 8;
+
+  public static final int NS_PARENT_KEY = 0;
+  public static final int NS_PATH_NODE_KEY = 1;
+  public static final int NS_PREFIX_KEY = 2;
+  public static final int NS_LOCAL_NAME_KEY = 3;
+  public static final int NS_URI_KEY = 4;
+  public static final int NS_PREV_REVISION = 5;
+  public static final int NS_LAST_MOD_REVISION = 6;
+  public static final int NS_HASH = 7;
+
+  // ==================== XML DOCUMENT ROOT NODE (7 fields) ====================
+
+  /** Total field count for XML_DOCUMENT_ROOT nodes. */
+  public static final int XML_DOCUMENT_ROOT_FIELD_COUNT = 7;
+
+  public static final int XDOCROOT_FIRST_CHILD_KEY = 0;
+  public static final int XDOCROOT_LAST_CHILD_KEY = 1;
+  public static final int XDOCROOT_CHILD_COUNT = 2;
+  public static final int XDOCROOT_DESCENDANT_COUNT = 3;
+  public static final int XDOCROOT_PREV_REVISION = 4;
+  public static final int XDOCROOT_LAST_MOD_REVISION = 5;
+  public static final int XDOCROOT_HASH = 6;
+
+  // ==================== FIELD COUNT LOOKUP ====================
+
+  /**
+   * Get the field count for a given NodeKind.
+   *
+   * @param kindId the NodeKind byte ID
+   * @return the field count, or -1 if unknown/unsupported
+   */
+  public static int fieldCountForKind(final int kindId) {
+    return switch (kindId) {
+      case 1 -> ELEMENT_FIELD_COUNT;            // ELEMENT
+      case 2 -> ATTRIBUTE_FIELD_COUNT;           // ATTRIBUTE
+      case 3 -> TEXT_FIELD_COUNT;                // TEXT
+      case 7 -> PI_FIELD_COUNT;                  // PROCESSING_INSTRUCTION
+      case 8 -> COMMENT_FIELD_COUNT;             // COMMENT
+      case 9 -> XML_DOCUMENT_ROOT_FIELD_COUNT;   // XML_DOCUMENT
+      case 13 -> NAMESPACE_FIELD_COUNT;          // NAMESPACE
+      case 24 -> OBJECT_FIELD_COUNT;             // OBJECT
+      case 25 -> ARRAY_FIELD_COUNT;              // ARRAY
+      case 26 -> OBJECT_KEY_FIELD_COUNT;         // OBJECT_KEY
+      case 27 -> BOOLEAN_VALUE_FIELD_COUNT;      // BOOLEAN_VALUE
+      case 28 -> NUMBER_VALUE_FIELD_COUNT;       // NUMBER_VALUE
+      case 29 -> NULL_VALUE_FIELD_COUNT;         // NULL_VALUE
+      case 30 -> STRING_VALUE_FIELD_COUNT;       // STRING_VALUE
+      case 31 -> JSON_DOCUMENT_ROOT_FIELD_COUNT; // JSON_DOCUMENT_ROOT
+      case 40 -> OBJECT_STRING_VALUE_FIELD_COUNT;   // OBJECT_STRING_VALUE
+      case 41 -> OBJECT_BOOLEAN_VALUE_FIELD_COUNT;  // OBJECT_BOOLEAN_VALUE
+      case 42 -> OBJECT_NUMBER_VALUE_FIELD_COUNT;   // OBJECT_NUMBER_VALUE
+      case 43 -> OBJECT_NULL_VALUE_FIELD_COUNT;     // OBJECT_NULL_VALUE
+      default -> -1;
+    };
+  }
+
+  /**
+   * Get the field count for a given NodeKind enum.
+   *
+   * @param kind the NodeKind
+   * @return the field count, or -1 if unsupported
+   */
+  public static int fieldCountForKind(final NodeKind kind) {
+    return fieldCountForKind(kind.getId());
+  }
+}
diff --git a/bundles/sirix-core/src/main/java/io/sirix/page/PageKind.java b/bundles/sirix-core/src/main/java/io/sirix/page/PageKind.java
index cf839f007..26e0ca04c 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/page/PageKind.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/page/PageKind.java
@@ -43,7 +43,6 @@
 import java.lang.foreign.ValueLayout;
 import io.sirix.node.Utils;
 import io.sirix.node.Bytes;
-import io.sirix.node.interfaces.DeweyIdSerializer;
 import io.sirix.node.interfaces.RecordSerializer;
 import io.sirix.page.delegates.BitmapReferencesPage;
 import io.sirix.page.delegates.FullReferencesPage;
@@ -84,343 +83,253 @@ public Page deserializePage(final ResourceConfiguration resourceConfig, final By
 
       switch (binaryVersion) {
         case V0 -> {
-          final long recordPageKey = Utils.getVarLong(source);
-          final int revision = source.readInt();
-          final IndexType indexType = IndexType.getType(source.readByte());
-          final int lastSlotIndex = source.readInt();
-
-          // Read compressed slot offsets (delta + bit-packed)
-          final int[] slotOffsets = SlotOffsetCodec.decode(source);
-
-          // Read slotMemory size
-          final int slotMemorySize = source.readInt();
-
-          // ZERO-COPY: Slice decompression buffer directly as slotMemory
-          // This eliminates per-slot MemorySegment.copy() calls (major performance win)
-          final boolean canZeroCopy = decompressionResult != null && source instanceof MemorySegmentBytesIn;
-          final MemorySegment slotMemory;
-          final MemorySegment backingBuffer;
-          final Runnable backingBufferReleaser;
-
-          MemorySegmentAllocator memorySegmentAllocator = OS.isWindows()
-              ? WindowsMemorySegmentAllocator.getInstance()
-              : LinuxMemorySegmentAllocator.getInstance();
-          if (canZeroCopy) {
-            // Zero-copy path: slice decompression buffer directly
-            final MemorySegment sourceSegment = ((MemorySegmentBytesIn) source).getSource();
-            slotMemory = sourceSegment.asSlice(source.position(), slotMemorySize);
-            source.skip(slotMemorySize);
-
-            // Transfer buffer ownership to page
-            backingBufferReleaser = decompressionResult.transferOwnership();
-            backingBuffer = decompressionResult.backingBuffer();
-          } else {
-            // Fallback: allocate and copy (for non-MemorySegment sources or no decompressionResult)
-            MemorySegmentAllocator allocator = memorySegmentAllocator;
-            slotMemory = allocator.allocate(slotMemorySize);
-
-            // Copy slot data
-            if (source instanceof MemorySegmentBytesIn msSource) {
-              MemorySegment.copy(msSource.getSource(), source.position(), slotMemory, 0, slotMemorySize);
-              source.skip(slotMemorySize);
-            } else {
-              byte[] slotData = new byte[slotMemorySize];
-              source.read(slotData);
-              MemorySegment.copy(slotData, 0, slotMemory, java.lang.foreign.ValueLayout.JAVA_BYTE, 0, slotMemorySize);
-            }
-            backingBuffer = null;
-            backingBufferReleaser = null;
-          }
+          return deserializeSlottedPage(resourceConfig, source);
+        }
+        default -> throw new IllegalStateException("Unknown binary encoding version: " + binaryVersion);
+      }
+    }
 
-          // Read dewey ID data if stored
-          final boolean areDeweyIDsStored = resourceConfig.areDeweyIDsStored;
-          final RecordSerializer recordPersister = resourceConfig.recordPersister;
-          final int[] deweyIdOffsets;
-          final MemorySegment deweyIdMemory;
-          final int lastDeweyIdIndex;
-
-          if (areDeweyIDsStored && recordPersister instanceof DeweyIdSerializer) {
-            lastDeweyIdIndex = source.readInt();
-
-            // Read compressed dewey ID offsets (delta + bit-packed)
-            deweyIdOffsets = SlotOffsetCodec.decode(source);
-
-            // Read deweyIdMemory size and data
-            final int deweyIdMemorySize = source.readInt();
-
-            if (canZeroCopy && deweyIdMemorySize > 1) {
-              // Zero-copy for dewey IDs too (part of same backing buffer)
-              final MemorySegment sourceSegment = ((MemorySegmentBytesIn) source).getSource();
-              deweyIdMemory = sourceSegment.asSlice(source.position(), deweyIdMemorySize);
-              source.skip(deweyIdMemorySize);
-            } else if (deweyIdMemorySize > 1) {
-              // Allocate and copy
-              MemorySegmentAllocator allocator = memorySegmentAllocator;
-              deweyIdMemory = allocator.allocate(deweyIdMemorySize);
-
-              if (source instanceof MemorySegmentBytesIn msSource) {
-                MemorySegment.copy(msSource.getSource(), source.position(), deweyIdMemory, 0, deweyIdMemorySize);
-                source.skip(deweyIdMemorySize);
-              } else {
-                byte[] deweyData = new byte[deweyIdMemorySize];
-                source.read(deweyData);
-                MemorySegment.copy(deweyData, 0, deweyIdMemory, java.lang.foreign.ValueLayout.JAVA_BYTE, 0,
-                    deweyIdMemorySize);
-              }
-            } else {
-              deweyIdMemory = null;
-              source.skip(1); // Skip placeholder byte
-            }
-          } else {
-            deweyIdOffsets = null;
-            deweyIdMemory = null;
-            lastDeweyIdIndex = -1;
-          }
+    private Page deserializeSlottedPage(final ResourceConfiguration resourceConfig, final BytesIn source) {
+      final long recordPageKey = Utils.getVarLong(source);
+      final int revision = source.readInt();
+      final IndexType indexType = IndexType.getType(source.readByte());
 
-          // Read overlong entries bitmap
-          final var overlongEntriesBitmap = SerializationType.deserializeBitSet(source);
-
-          // Read overlong entries
-          final int overlongEntrySize = source.readInt();
-          final Map references = new LinkedHashMap<>(overlongEntrySize);
-          var setBit = -1;
-
-          for (int index = 0; index < overlongEntrySize; index++) {
-            setBit = overlongEntriesBitmap.nextSetBit(setBit + 1);
-            assert setBit >= 0;
-            final long key = (recordPageKey << Constants.NDP_NODE_COUNT_EXPONENT) + setBit;
-            final PageReference reference = new PageReference();
-            reference.setKey(source.readLong());
-            references.put(key, reference);
-          }
+      final MemorySegmentAllocator memorySegmentAllocator =
+          OS.isWindows() ? WindowsMemorySegmentAllocator.getInstance() : LinuxMemorySegmentAllocator.getInstance();
 
-          // Read FSST symbol table for string compression
-          byte[] fsstSymbolTable = null;
-          final int fsstSymbolTableLength = source.readInt();
-          if (fsstSymbolTableLength > 0) {
-            fsstSymbolTable = new byte[fsstSymbolTableLength];
-            source.read(fsstSymbolTable);
-          }
+      // 1. Read header (32B) + bitmap (128B) — 160 bytes
+      final byte[] headerBitmapBytes = new byte[PageLayout.DIR_OFF];
+      source.read(headerBitmapBytes);
+      final MemorySegment headerBitmapSeg = MemorySegment.ofArray(headerBitmapBytes);
+      final int populatedCount = PageLayout.getPopulatedCount(headerBitmapSeg);
 
-          // Read columnar string storage if present
-          // Format: [hasColumnar:1][size:4][offsets:bit-packed][data:N]
-          MemorySegment stringValueMemory = null;
-          int[] stringValueOffsets = null;
-          int lastStringValueIndex = -1;
-          int stringValueMemorySize = 0;
-
-          byte hasColumnar = source.readByte();
-          if (hasColumnar == 1) {
-            stringValueMemorySize = source.readInt();
-            stringValueOffsets = SlotOffsetCodec.decode(source);
-
-            // Find last string value index from offsets
-            for (int i = stringValueOffsets.length - 1; i >= 0; i--) {
-              if (stringValueOffsets[i] >= 0) {
-                lastStringValueIndex = i;
-                break;
-              }
-            }
-
-            // Read columnar data - zero-copy if possible
-            if (canZeroCopy && stringValueMemorySize > 0) {
-              final MemorySegment sourceSegment = ((MemorySegmentBytesIn) source).getSource();
-              stringValueMemory = sourceSegment.asSlice(source.position(), stringValueMemorySize);
-              source.skip(stringValueMemorySize);
-            } else if (stringValueMemorySize > 0) {
-              stringValueMemory = memorySegmentAllocator.allocate(stringValueMemorySize);
-              if (source instanceof MemorySegmentBytesIn msSource) {
-                MemorySegment.copy(msSource.getSource(), source.position(), stringValueMemory, 0,
-                    stringValueMemorySize);
-                source.skip(stringValueMemorySize);
-              } else {
-                byte[] stringData = new byte[stringValueMemorySize];
-                source.read(stringData);
-                MemorySegment.copy(stringData, 0, stringValueMemory, java.lang.foreign.ValueLayout.JAVA_BYTE, 0,
-                    stringValueMemorySize);
-              }
-            }
-          }
+      // 2. Read compact dir entries: populatedCount × 4 bytes
+      final int[] compactDir = new int[populatedCount];
+      for (int i = 0; i < populatedCount; i++) {
+        compactDir[i] = source.readInt();
+      }
 
-          // Create page - use the zero-copy constructor for both paths
-          // (it properly handles slotOffsets; backingBuffer/releaser can be null for non-zero-copy)
-          KeyValueLeafPage page = new KeyValueLeafPage(recordPageKey, revision, indexType, resourceConfig, slotOffsets,
-              slotMemory, lastSlotIndex, deweyIdOffsets, deweyIdMemory, lastDeweyIdIndex, references, backingBuffer,
-              backingBufferReleaser);
-
-          // Set FSST symbol table if present and propagate to any deserialized nodes
-          if (fsstSymbolTable != null) {
-            page.setFsstSymbolTable(fsstSymbolTable);
-            // Propagate symbol table to nodes that are already in the records array
-            // Lazily-deserialized nodes will get the table when accessed via getRecord()
-            page.propagateFsstSymbolTableToNodes();
-          }
+      // 3. Read heap size
+      final int heapSize = source.readInt();
 
-          // Set columnar string storage if present
-          if (stringValueMemory != null && stringValueOffsets != null) {
-            page.setStringValueData(stringValueMemory, stringValueOffsets, lastStringValueIndex, stringValueMemorySize);
-          }
+      // 4. Allocate slotted page MemorySegment
+      final int allocSize = Math.max(PageLayout.HEAP_START + heapSize, PageLayout.INITIAL_PAGE_SIZE);
+      final MemorySegment slottedPage = memorySegmentAllocator.allocate(allocSize);
+
+      // 5. Copy header + bitmap into page
+      MemorySegment.copy(headerBitmapSeg, 0, slottedPage, 0, PageLayout.DIR_OFF);
 
-          return page;
+      // 6. Zero-fill directory region (will be rebuilt from compact dir)
+      slottedPage.asSlice(PageLayout.DIR_OFF, PageLayout.DIR_SIZE).fill((byte) 0);
+
+      // 7. Read heap data into page at HEAP_START
+      if (source instanceof MemorySegmentBytesIn msSource) {
+        MemorySegment.copy(msSource.getSource(), source.position(), slottedPage, PageLayout.HEAP_START, heapSize);
+        source.skip(heapSize);
+      } else {
+        final byte[] heapData = new byte[heapSize];
+        source.read(heapData);
+        MemorySegment.copy(heapData, 0, slottedPage, ValueLayout.JAVA_BYTE, PageLayout.HEAP_START, heapData.length);
+      }
+
+      // 8. Zero-fill remainder of allocated page
+      final long usedEnd = PageLayout.HEAP_START + heapSize;
+      if (allocSize > usedEnd) {
+        slottedPage.asSlice(usedEnd, allocSize - usedEnd).fill((byte) 0);
+      }
+
+      // 9. Rebuild full directory via prefix sums from compact dir entries
+      int entryIdx = 0;
+      int heapOffset = 0;
+      for (int w = 0; w < PageLayout.BITMAP_WORDS; w++) {
+        long word = PageLayout.getBitmapWord(slottedPage, w);
+        while (word != 0) {
+          final int bit = Long.numberOfTrailingZeros(word);
+          final int slot = (w << 6) | bit;
+          final int packed = compactDir[entryIdx++];
+          final int dataLength = packed >>> 8;
+          final int nodeKindId = packed & 0xFF;
+          PageLayout.setDirEntry(slottedPage, slot, heapOffset, dataLength, nodeKindId);
+          heapOffset += dataLength;
+          word &= word - 1; // clear lowest set bit
         }
-        default -> throw new IllegalStateException();
       }
+
+      // 10. Set heapEnd and heapUsed (both = heapSize since deserialized heap is contiguous/defragmented)
+      PageLayout.setHeapEnd(slottedPage, heapSize);
+      PageLayout.setHeapUsed(slottedPage, heapSize);
+
+      final boolean areDeweyIDsStored = resourceConfig.areDeweyIDsStored;
+      final RecordSerializer recordPersister = resourceConfig.recordPersister;
+
+      // Read overlong entries
+      final var overlongEntriesBitmap = SerializationType.deserializeBitSet(source);
+      final int overlongEntrySize = source.readInt();
+      final Map references = new LinkedHashMap<>(overlongEntrySize);
+      var setBit = -1;
+      for (int index = 0; index < overlongEntrySize; index++) {
+        setBit = overlongEntriesBitmap.nextSetBit(setBit + 1);
+        assert setBit >= 0;
+        final long key = (recordPageKey << Constants.NDP_NODE_COUNT_EXPONENT) + setBit;
+        final PageReference reference = new PageReference();
+        reference.setKey(source.readLong());
+        references.put(key, reference);
+      }
+
+      // Read FSST symbol table
+      byte[] fsstSymbolTable = null;
+      final int fsstSymbolTableLength = source.readInt();
+      if (fsstSymbolTableLength > 0) {
+        fsstSymbolTable = new byte[fsstSymbolTableLength];
+        source.read(fsstSymbolTable);
+      }
+
+      // Create page with dummy slotMemory; slotted page overrides all slot operations
+      final MemorySegment dummySlotMemory = memorySegmentAllocator.allocate(1);
+      final KeyValueLeafPage page = new KeyValueLeafPage(
+          recordPageKey, revision, indexType, resourceConfig,
+          areDeweyIDsStored, recordPersister, references,
+          dummySlotMemory, null, -1, -1);
+
+      page.setSlottedPage(slottedPage);
+
+      if (fsstSymbolTable != null) {
+        page.setFsstSymbolTable(fsstSymbolTable);
+      }
+
+      return page;
     }
 
     @Override
     public void serializePage(final ResourceConfiguration resourceConfig, final BytesOut sink, final Page page,
         final SerializationType type) {
-      KeyValueLeafPage keyValueLeafPage = (KeyValueLeafPage) page;
+      final KeyValueLeafPage keyValueLeafPage = (KeyValueLeafPage) page;
 
-      final var bytes = keyValueLeafPage.getBytes();
+      // Check for zero-copy compressed segment first
+      final MemorySegment cachedSegment = keyValueLeafPage.getCompressedSegment();
+      if (cachedSegment != null) {
+        sink.writeSegment(cachedSegment, 0, cachedSegment.byteSize());
+        return;
+      }
 
+      // Legacy byte[] cache fallback
+      final var bytes = keyValueLeafPage.getBytes();
       if (bytes != null) {
         sink.write(bytes.toByteArray());
         return;
       }
 
+      // Ensure slotted page exists — ALL pages use slotted page format V0
+      keyValueLeafPage.ensureSlottedPage();
+
       sink.writeByte(KEYVALUELEAFPAGE.id);
       sink.writeByte(resourceConfig.getBinaryEncodingVersion().byteVersion());
 
-      // Variables from keyValueLeafPage
-      final long recordPageKey = keyValueLeafPage.getPageKey();
-      final IndexType indexType = keyValueLeafPage.getIndexType();
-      final RecordSerializer recordPersister = resourceConfig.recordPersister;
       final Map references = keyValueLeafPage.getReferencesMap();
 
-      // Compact fixed-format slots to delta+varint encoding first.
-      // This must happen before FSST so the symbol table builder sees compact bytes.
-      keyValueLeafPage.compactFixedSlotsForCommit(resourceConfig);
-
       // Build FSST symbol table and compress strings BEFORE addReferences() serializes them
       keyValueLeafPage.buildFsstSymbolTable(resourceConfig);
       keyValueLeafPage.compressStringValues();
 
-      // Add references to overflow pages if necessary.
+      // addReferences: serializes records to slotted page heap via processEntries,
+      // copies preserved slots from completePageRef for DIFFERENTIAL/INCREMENTAL versioning
       keyValueLeafPage.addReferences(resourceConfig);
 
-      // Write page key.
-      Utils.putVarLong(sink, recordPageKey);
-      // Write revision number.
+      // Write metadata
+      Utils.putVarLong(sink, keyValueLeafPage.getPageKey());
       sink.writeInt(keyValueLeafPage.getRevision());
-      // Write index type.
-      sink.writeByte(indexType.getID());
-      // Write last slot index.
-      sink.writeInt(keyValueLeafPage.getLastSlotIndex());
-
-      // Write compressed slot offsets (delta + bit-packed) - ~75% smaller than raw int[1024]
-      final int[] slotOffsets = keyValueLeafPage.getSlotOffsets();
-      final MemorySegment slotMemory = keyValueLeafPage.getSlotMemory();
-      final CompactedRegion compactedSlots = compactLengthPrefixedRegion(slotOffsets, slotMemory);
-      SlotOffsetCodec.encode(sink, compactedSlots.offsets(), keyValueLeafPage.getLastSlotIndex());
-
-      // Write compacted slotMemory region.
-      int slotMemoryUsedSize = compactedSlots.usedSize();
-      if (slotMemoryUsedSize == 0) {
-        slotMemoryUsedSize = 1;
-      }
-      sink.writeInt(slotMemoryUsedSize);
-      if (compactedSlots.usedSize() > 0) {
-        writeCompactedLengthPrefixedRegion(sink, slotMemory, slotOffsets, compactedSlots.offsets(),
-            compactedSlots.usedSize());
-      } else {
-        sink.writeByte((byte) 0);
+      sink.writeByte(keyValueLeafPage.getIndexType().getID());
+
+      // Write compact on-disk format: header+bitmap, compact dir, heap (no 8KB slot directory)
+      final MemorySegment slottedPage = keyValueLeafPage.getSlottedPage();
+
+      // 1. Write header (32B) + bitmap (128B) — 160 bytes
+      sink.writeSegment(slottedPage, 0, PageLayout.DIR_OFF);
+
+      // 2. Single-pass bitmap scan: write compact dir entries, collect heap copy info
+      final int populatedCount = PageLayout.getPopulatedCount(slottedPage);
+      final int[] slotHeapOffsets = new int[populatedCount];
+      final int[] slotDataLengths = new int[populatedCount];
+      int entryIdx = 0;
+      int totalHeapSize = 0;
+
+      for (int w = 0; w < PageLayout.BITMAP_WORDS; w++) {
+        long word = PageLayout.getBitmapWord(slottedPage, w);
+        while (word != 0) {
+          final int bit = Long.numberOfTrailingZeros(word);
+          final int slot = (w << 6) | bit;
+          final int dataLength = PageLayout.getDirDataLength(slottedPage, slot);
+          final int nodeKindId = PageLayout.getDirNodeKindId(slottedPage, slot);
+          sink.writeInt(PageLayout.packCompactDirEntry(dataLength, nodeKindId));
+          slotHeapOffsets[entryIdx] = PageLayout.getDirHeapOffset(slottedPage, slot);
+          slotDataLengths[entryIdx] = dataLength;
+          totalHeapSize += dataLength;
+          entryIdx++;
+          word &= word - 1; // clear lowest set bit
+        }
       }
 
-      // Write dewey ID data if stored
-      if (resourceConfig.areDeweyIDsStored && recordPersister instanceof DeweyIdSerializer) {
-        // Write last dewey ID index
-        sink.writeInt(keyValueLeafPage.getLastDeweyIdIndex());
-
-        // Write compressed dewey ID offsets (delta + bit-packed)
-        final int[] deweyIdOffsets = keyValueLeafPage.getDeweyIdOffsets();
-        final MemorySegment deweyIdMemory = keyValueLeafPage.getDeweyIdMemory();
-        final CompactedRegion compactedDeweyIds = compactLengthPrefixedRegion(deweyIdOffsets, deweyIdMemory);
-        SlotOffsetCodec.encode(sink, compactedDeweyIds.offsets(), keyValueLeafPage.getLastDeweyIdIndex());
-
-        // Write compacted deweyIdMemory region.
-        int deweyIdMemoryUsedSize = compactedDeweyIds.usedSize();
-        if (deweyIdMemoryUsedSize == 0) {
-          deweyIdMemoryUsedSize = 1;
-        }
-        sink.writeInt(deweyIdMemoryUsedSize);
-        if (compactedDeweyIds.usedSize() > 0) {
-          writeCompactedLengthPrefixedRegion(sink, deweyIdMemory, deweyIdOffsets, compactedDeweyIds.offsets(),
-              compactedDeweyIds.usedSize());
-        } else {
-          // Write a single byte placeholder if no dewey ID memory
-          sink.writeByte((byte) 0);
-        }
+      // 3. Write heap size
+      sink.writeInt(totalHeapSize);
+
+      // 4. Write heap data: slot by slot in bitmap order (contiguous on disk)
+      for (int i = 0; i < populatedCount; i++) {
+        sink.writeSegment(slottedPage, PageLayout.HEAP_START + slotHeapOffsets[i], slotDataLengths[i]);
       }
 
-      // Write overlong entries bitmap (entries bitmap is not needed - slot presence determined by
-      // slotOffsets)
+      // Write overlong entries
+      writeOverlongEntries(sink, references);
+
+      // Write FSST symbol table
+      writeFsstSymbolTable(sink, keyValueLeafPage);
+
+      // Compress the serialized data
+      compressAndCache(resourceConfig, sink, keyValueLeafPage);
+
+      // Release node object references — all data is now in the slotted page + compressed cache
+      keyValueLeafPage.clearRecordsForGC();
+    }
+
+    private static void writeOverlongEntries(final BytesOut sink, final Map references) {
       var overlongEntriesBitmap = new BitSet(Constants.NDP_NODE_COUNT);
-      final var overlongEntriesSortedByKey = references.entrySet().stream().sorted(Map.Entry.comparingByKey()).toList();
+      final var overlongEntriesSortedByKey = references.entrySet().stream()
+          .sorted(Map.Entry.comparingByKey()).toList();
 
       for (final Map.Entry entry : overlongEntriesSortedByKey) {
         final var pageOffset = StorageEngineReader.recordPageOffset(entry.getKey());
         overlongEntriesBitmap.set(pageOffset);
       }
       SerializationType.serializeBitSet(sink, overlongEntriesBitmap);
-
-      // Write overlong entries.
       sink.writeInt(overlongEntriesSortedByKey.size());
       for (final var entry : overlongEntriesSortedByKey) {
-        // Write key in persistent storage.
         sink.writeLong(entry.getValue().getKey());
       }
+    }
 
-      // Write FSST symbol table for string compression
-      final byte[] fsstSymbolTable = keyValueLeafPage.getFsstSymbolTable();
+    private static void writeFsstSymbolTable(final BytesOut sink, final KeyValueLeafPage page) {
+      final byte[] fsstSymbolTable = page.getFsstSymbolTable();
       if (fsstSymbolTable != null && fsstSymbolTable.length > 0) {
         sink.writeInt(fsstSymbolTable.length);
         sink.write(fsstSymbolTable);
       } else {
-        sink.writeInt(0); // No symbol table
-      }
-
-      // Write columnar string storage if present
-      // Format: [hasColumnar:1][size:4][offsets:bit-packed][data:N]
-      if (keyValueLeafPage.hasColumnarStringStorage()) {
-        sink.writeByte((byte) 1); // Has columnar data
-        final int[] stringValueOffsets = keyValueLeafPage.getStringValueOffsets();
-        final MemorySegment stringValueMemory = keyValueLeafPage.getStringValueMemory();
-        final CompactedRegion compactedStrings = compactLengthPrefixedRegion(stringValueOffsets, stringValueMemory);
-        final int columnarSize = compactedStrings.usedSize();
-        sink.writeInt(columnarSize);
-
-        // Write bit-packed string value offsets
-        SlotOffsetCodec.encode(sink, compactedStrings.offsets(), keyValueLeafPage.getLastStringValueIndex());
-
-        // Write compacted columnar string data.
-        if (columnarSize > 0) {
-          writeCompactedLengthPrefixedRegion(sink, stringValueMemory, stringValueOffsets, compactedStrings.offsets(),
-              columnarSize);
-        }
-      } else {
-        sink.writeByte((byte) 0); // No columnar data
+        sink.writeInt(0);
       }
+    }
 
+    private static void compressAndCache(final ResourceConfiguration resourceConfig, final BytesOut sink,
+        final KeyValueLeafPage keyValueLeafPage) {
       final BytesIn uncompressedBytes = sink.bytesForRead();
-      final long uncompressedLength = sink.writePosition();
       final ByteHandlerPipeline pipeline = resourceConfig.byteHandlePipeline;
 
-      final byte[] compressedPage;
       if (pipeline.supportsMemorySegments() && uncompressedBytes instanceof MemorySegmentBytesIn segmentIn) {
-        // MemorySegment path — compress directly without materializing uncompressed byte[]
-        final MemorySegment uncompressedSegment = segmentIn.getSource().asSlice(0, uncompressedLength);
-        final MemorySegment compressedSegment = pipeline.compress(uncompressedSegment);
-        compressedPage = segmentToByteArray(compressedSegment);
+        final MemorySegment uncompressed = segmentIn.getSource().asSlice(0, sink.writePosition());
+        final MemorySegment compressed = pipeline.compress(uncompressed);
+        keyValueLeafPage.setCompressedSegment(compressed);
       } else {
-        // Fallback: materialize to byte[] for stream-based compression
         final byte[] uncompressedArray = uncompressedBytes.toByteArray();
-        compressedPage = compressViaStream(pipeline, uncompressedArray);
+        final byte[] compressedPage = compressViaStream(pipeline, uncompressedArray);
+        keyValueLeafPage.setBytes(Bytes.wrapForWrite(compressedPage));
       }
-
-      // Cache compressed form for writers, but leave the sink unmodified (uncompressed)
-      // so in-memory round-trips that bypass the ByteHandler still work.
-      keyValueLeafPage.setBytes(Bytes.wrapForWrite(compressedPage));
     }
   },
 
@@ -572,14 +481,21 @@ public Page deserializePage(final ResourceConfiguration resourceConfiguration, f
           final int currentMaxLevelOfRecordToRevisionsIndirectPages = source.readByte() & 0xFF;
 
           if (source.readBoolean()) {
-            // noinspection DataFlowIssue
+            //noinspection DataFlowIssue
             user = new User(source.readUtf8(), UUID.fromString(source.readUtf8()));
           }
 
-          return new RevisionRootPage(delegate, revision, maxNodeKeyInDocumentIndex, maxNodeKeyInChangedNodesIndex,
-              maxNodeKeyInRecordToRevisionsIndex, revisionTimestamp, commitMessage,
-              currentMaxLevelOfDocumentIndexIndirectPages, currentMaxLevelOfChangedNodesIndirectPages,
-              currentMaxLevelOfRecordToRevisionsIndirectPages, user);
+          return new RevisionRootPage(delegate,
+                                      revision,
+                                      maxNodeKeyInDocumentIndex,
+                                      maxNodeKeyInChangedNodesIndex,
+                                      maxNodeKeyInRecordToRevisionsIndex,
+                                      revisionTimestamp,
+                                      commitMessage,
+                                      currentMaxLevelOfDocumentIndexIndirectPages,
+                                      currentMaxLevelOfChangedNodesIndirectPages,
+                                      currentMaxLevelOfRecordToRevisionsIndirectPages,
+                                      user);
         }
         default -> throw new IllegalStateException();
       }
@@ -595,7 +511,7 @@ public void serializePage(final ResourceConfiguration resourceConfig, final Byte
       Page delegate = revisionRootPage.delegate();
       PageKind.serializeDelegate(sink, delegate, type);
 
-      // initial variables from RevisionRootPage, to serialize
+      //initial variables from RevisionRootPage, to serialize
       final Instant commitTimestamp = revisionRootPage.getCommitTimestamp();
       final int revision = revisionRootPage.getRevision();
       final long maxNodeKeyInDocumentIndex = revisionRootPage.getMaxNodeKeyInDocumentIndex();
@@ -608,9 +524,8 @@ public void serializePage(final ResourceConfiguration resourceConfig, final Byte
           revisionRootPage.getCurrentMaxLevelOfChangedNodesIndexIndirectPages();
       final int currentMaxLevelOfRecordToRevisionsIndirectPages =
           revisionRootPage.getCurrentMaxLevelOfRecordToRevisionsIndexIndirectPages();
-      final long revisionTimestamp = commitTimestamp == null
-          ? Instant.now().toEpochMilli()
-          : commitTimestamp.toEpochMilli();
+      final long revisionTimestamp =
+          commitTimestamp == null ? Instant.now().toEpochMilli() : commitTimestamp.toEpochMilli();
       revisionRootPage.setRevisionTimestamp(revisionTimestamp);
 
       sink.writeInt(revision);
@@ -775,7 +690,7 @@ public void serializePage(final ResourceConfiguration resourceConfig, final Byte
       OverflowPage overflowPage = (OverflowPage) page;
       sink.writeByte(OVERFLOWPAGE.id);
       sink.writeByte(resourceConfig.getBinaryEncodingVersion().byteVersion());
-
+      
       // Write byte array directly
       byte[] data = overflowPage.getDataBytes();
       sink.writeInt(data.length);
@@ -873,28 +788,28 @@ public void serializePage(@NonNull ResourceConfiguration resourceConfig, BytesOu
     public Page deserializePage(@NonNull ResourceConfiguration resourceConfiguration, BytesIn source,
         @NonNull SerializationType type, final ByteHandler.DecompressionResult decompressionResult) {
       final BinaryEncodingVersion binaryVersion = BinaryEncodingVersion.fromByte(source.readByte());
-
+      
       // Read header
       final long recordPageKey = Utils.getVarLong(source);
       final int revision = source.readInt();
       final IndexType indexType = IndexType.getType(source.readByte());
       final int entryCount = source.readInt();
       final int usedSlotMemorySize = source.readInt();
-
+      
       // Read slot offsets (allocate MAX_ENTRIES to allow insertions after deserialization)
       final int[] slotOffsets = new int[HOTLeafPage.MAX_ENTRIES];
       for (int i = 0; i < entryCount; i++) {
         slotOffsets[i] = source.readInt();
       }
-
+      
       // Read slot memory (zero-copy when possible)
-      MemorySegmentAllocator allocator = OS.isWindows()
-          ? WindowsMemorySegmentAllocator.getInstance()
+      MemorySegmentAllocator allocator = OS.isWindows() 
+          ? WindowsMemorySegmentAllocator.getInstance() 
           : LinuxMemorySegmentAllocator.getInstance();
-
+      
       final MemorySegment slotMemory;
       final Runnable releaser;
-
+      
       // Note: For zero-copy we use just the needed size, but for regular allocation we use DEFAULT_SIZE
       // to allow insertions after deserialization.
       final boolean canZeroCopy = decompressionResult != null && source instanceof MemorySegmentBytesIn;
@@ -918,9 +833,9 @@ public Page deserializePage(@NonNull ResourceConfiguration resourceConfiguration
         final MemorySegment segmentToRelease = slotMemory;
         releaser = () -> allocator.release(segmentToRelease);
       }
-
-      return new HOTLeafPage(recordPageKey, revision, indexType, slotMemory, releaser, slotOffsets, entryCount,
-          usedSlotMemorySize);
+      
+      return new HOTLeafPage(recordPageKey, revision, indexType, slotMemory, releaser, 
+                             slotOffsets, entryCount, usedSlotMemorySize);
     }
 
     @Override
@@ -929,14 +844,14 @@ public void serializePage(@NonNull ResourceConfiguration resourceConfig, @NonNul
       HOTLeafPage hotLeaf = (HOTLeafPage) page;
       sink.writeByte(HOT_LEAF_PAGE.id);
       sink.writeByte(resourceConfig.getBinaryEncodingVersion().byteVersion());
-
+      
       // Write header
       Utils.putVarLong(sink, hotLeaf.getPageKey());
       sink.writeInt(hotLeaf.getRevision());
       sink.writeByte(hotLeaf.getIndexType().getID());
       sink.writeInt(hotLeaf.getEntryCount());
       sink.writeInt(hotLeaf.getUsedSlotsSize());
-
+      
       // Write slot offsets
       int entryCount = hotLeaf.getEntryCount();
       for (int i = 0; i < entryCount; i++) {
@@ -948,7 +863,7 @@ public void serializePage(@NonNull ResourceConfiguration resourceConfig, @NonNul
           sink.writeInt(0);
         }
       }
-
+      
       // Write slot memory (bulk copy)
       MemorySegment slots = hotLeaf.slots();
       int usedSize = hotLeaf.getUsedSlotsSize();
@@ -966,7 +881,7 @@ public void serializePage(@NonNull ResourceConfiguration resourceConfig, @NonNul
     public Page deserializePage(@NonNull ResourceConfiguration resourceConfiguration, BytesIn source,
         @NonNull SerializationType type, final ByteHandler.DecompressionResult decompressionResult) {
       final BinaryEncodingVersion binaryVersion = BinaryEncodingVersion.fromByte(source.readByte());
-
+      
       // Read header
       final long pageKey = Utils.getVarLong(source);
       final int revision = source.readInt();
@@ -974,17 +889,17 @@ public Page deserializePage(@NonNull ResourceConfiguration resourceConfiguration
       final byte nodeTypeId = source.readByte();
       final byte layoutTypeId = source.readByte();
       final int numChildren = source.readInt();
-
+      
       final HOTIndirectPage.NodeType nodeType = HOTIndirectPage.NodeType.values()[nodeTypeId];
-
+      
       // Read discriminative bits based on layout type
       final byte initialBytePos = source.readByte();
       final long bitMask = source.readLong();
-
+      
       // Read partial keys
       final byte[] partialKeys = new byte[numChildren];
       source.read(partialKeys);
-
+      
       // Read child references (simple key-only format)
       final PageReference[] children = new PageReference[numChildren];
       for (int i = 0; i < numChildren; i++) {
@@ -993,7 +908,7 @@ public Page deserializePage(@NonNull ResourceConfiguration resourceConfiguration
         ref.setKey(childKey);
         children[i] = ref;
       }
-
+      
       // Create appropriate node type
       return switch (nodeType) {
         case BI_NODE -> {
@@ -1007,8 +922,8 @@ public Page deserializePage(@NonNull ResourceConfiguration resourceConfiguration
           int discriminativeBitPos = (initialBytePos & 0xFF) * 8 + bitWithinByte;
           yield HOTIndirectPage.createBiNode(pageKey, revision, discriminativeBitPos, children[0], children[1]);
         }
-        case SPAN_NODE ->
-          HOTIndirectPage.createSpanNode(pageKey, revision, initialBytePos, bitMask, partialKeys, children);
+        case SPAN_NODE -> HOTIndirectPage.createSpanNode(pageKey, revision, 
+            initialBytePos, bitMask, partialKeys, children);
         case MULTI_NODE -> {
           byte[] childIndexArray = new byte[256];
           source.read(childIndexArray);
@@ -1023,7 +938,7 @@ public void serializePage(@NonNull ResourceConfiguration resourceConfig, @NonNul
       HOTIndirectPage hotIndirect = (HOTIndirectPage) page;
       sink.writeByte(HOT_INDIRECT_PAGE.id);
       sink.writeByte(resourceConfig.getBinaryEncodingVersion().byteVersion());
-
+      
       // Write header
       Utils.putVarLong(sink, hotIndirect.getPageKey());
       sink.writeInt(hotIndirect.getRevision());
@@ -1031,24 +946,22 @@ public void serializePage(@NonNull ResourceConfiguration resourceConfig, @NonNul
       sink.writeByte((byte) hotIndirect.getNodeType().ordinal());
       sink.writeByte((byte) hotIndirect.getLayoutType().ordinal());
       sink.writeInt(hotIndirect.getNumChildren());
-
+      
       // Write discriminative bits properly based on layout type
       sink.writeByte((byte) hotIndirect.getInitialBytePos());
       sink.writeLong(hotIndirect.getBitMask());
-
+      
       // Write partial keys
       byte[] partialKeysData = hotIndirect.getPartialKeys();
       sink.write(partialKeysData);
-
+      
       // Write child references
       for (int i = 0; i < hotIndirect.getNumChildren(); i++) {
         PageReference ref = hotIndirect.getChildReference(i);
-        long key = ref != null
-            ? ref.getKey()
-            : Constants.NULL_ID_LONG;
+        long key = ref != null ? ref.getKey() : Constants.NULL_ID_LONG;
         sink.writeLong(key);
       }
-
+      
       // For MultiNode, write the 256-byte child index array
       if (hotIndirect.getNodeType() == HOTIndirectPage.NodeType.MULTI_NODE) {
         byte[] childIdx = hotIndirect.getChildIndex();
@@ -1071,15 +984,16 @@ public Page deserializePage(@NonNull ResourceConfiguration resourceConfiguration
         @NonNull SerializationType type, final ByteHandler.DecompressionResult decompressionResult) {
       // Skip binary version byte for now
       source.readByte();
-
+      
       // Read page key (stored before calling deserialize)
       final long pageKey = Utils.getVarLong(source);
-
+      
       try {
         // Create a DataInputStream wrapper for BitmapChunkPage.deserialize
         byte[] remaining = source.toByteArray();
-        java.io.DataInputStream dis = new java.io.DataInputStream(new java.io.ByteArrayInputStream(remaining,
-            (int) source.position(), remaining.length - (int) source.position()));
+        java.io.DataInputStream dis = new java.io.DataInputStream(
+            new java.io.ByteArrayInputStream(remaining, (int) source.position(), 
+                remaining.length - (int) source.position()));
         return BitmapChunkPage.deserialize(dis, pageKey);
       } catch (java.io.IOException e) {
         throw new UncheckedIOException("Failed to deserialize BitmapChunkPage", e);
@@ -1092,10 +1006,10 @@ public void serializePage(@NonNull ResourceConfiguration resourceConfig, @NonNul
       BitmapChunkPage chunkPage = (BitmapChunkPage) page;
       sink.writeByte(BITMAP_CHUNK_PAGE.id);
       sink.writeByte(resourceConfig.getBinaryEncodingVersion().byteVersion());
-
+      
       // Write page key
       Utils.putVarLong(sink, chunkPage.getPageKey());
-
+      
       try {
         // Serialize to byte array first, then write
         ByteArrayOutputStream baos = new ByteArrayOutputStream();
@@ -1121,9 +1035,9 @@ private static void serializeDelegate(BytesOut sink, Page delegate, Serializa
     switch (delegate) {
       case ReferencesPage4 page -> type.serializeReferencesPage4(sink, page.getReferences(), page.getOffsets());
       case BitmapReferencesPage page ->
-        type.serializeBitmapReferencesPage(sink, page.getReferences(), page.getBitmap());
+          type.serializeBitmapReferencesPage(sink, page.getReferences(), page.getBitmap());
       case FullReferencesPage ignored ->
-        type.serializeFullReferencesPage(sink, ((FullReferencesPage) delegate).getReferencesArray());
+          type.serializeFullReferencesPage(sink, ((FullReferencesPage) delegate).getReferencesArray());
       default -> throw new IllegalStateException("Unexpected value: " + delegate);
     }
   }
@@ -1179,7 +1093,7 @@ private static Int2IntMap deserializeCurrentMaxLevelsOfIndirectPages(final Bytes
   /**
    * Constructor.
    *
-   * @param id unique identifier
+   * @param id    unique identifier
    * @param clazz class
    */
   PageKind(final byte id, final Class clazz) {
@@ -1196,9 +1110,30 @@ public byte getID() {
     return id;
   }
 
+  /**
+   * Compress the serialized page using the configured {@link ByteHandlerPipeline} and write the
+   * compressed bytes back to the provided sink. Uses the MemorySegment path when available to
+   * avoid intermediate byte[] allocations.
+   */
+  private static byte[] compress(ResourceConfiguration resourceConfig,
+                                 BytesIn uncompressedBytes,
+                                 byte[] uncompressedArray,
+                                 long uncompressedLength) {
+    final ByteHandlerPipeline pipeline = resourceConfig.byteHandlePipeline;
+
+    if (pipeline.supportsMemorySegments() && uncompressedBytes instanceof MemorySegmentBytesIn segmentIn) {
+      MemorySegment uncompressedSegment = segmentIn.getSource().asSlice(0, uncompressedLength);
+      MemorySegment compressedSegment = pipeline.compress(uncompressedSegment);
+      return segmentToByteArray(compressedSegment);
+    }
+
+    final byte[] compressedBytes = compressViaStream(pipeline, uncompressedArray);
+    return compressedBytes;
+  }
+
   private static byte[] compressViaStream(ByteHandlerPipeline pipeline, byte[] uncompressedArray) {
     try (final ByteArrayOutputStream output = new ByteArrayOutputStream(uncompressedArray.length);
-        final DataOutputStream dataOutput = new DataOutputStream(pipeline.serialize(output))) {
+         final DataOutputStream dataOutput = new DataOutputStream(pipeline.serialize(output))) {
       dataOutput.write(uncompressedArray);
       dataOutput.flush();
       return output.toByteArray();
@@ -1208,94 +1143,15 @@ private static byte[] compressViaStream(ByteHandlerPipeline pipeline, byte[] unc
   }
 
   private static byte[] segmentToByteArray(MemorySegment segment) {
-    return segment.toArray(java.lang.foreign.ValueLayout.JAVA_BYTE);
-  }
-
-  private static final ValueLayout.OfInt JAVA_INT_UNALIGNED = ValueLayout.JAVA_INT.withByteAlignment(1);
-  private static final int LENGTH_PREFIX_BYTES = Integer.BYTES;
-  private static final int LENGTH_PREFIX_ALIGNMENT = Integer.BYTES;
-
-  private static CompactedRegion compactLengthPrefixedRegion(final int[] sourceOffsets,
-      final MemorySegment sourceMemory) {
-    final int[] compactedOffsets = new int[sourceOffsets.length];
-    Arrays.fill(compactedOffsets, -1);
-
-    if (sourceMemory == null) {
-      return new CompactedRegion(compactedOffsets, 0);
-    }
-
-    int writeOffset = 0;
-    for (int slot = 0; slot < sourceOffsets.length; slot++) {
-      final int sourceOffset = sourceOffsets[slot];
-      if (sourceOffset < 0) {
-        continue;
-      }
-
-      final int alignedWriteOffset = alignOffset(writeOffset);
-      compactedOffsets[slot] = alignedWriteOffset;
-
-      final int entryLength = readLengthPrefix(sourceMemory, sourceOffset);
-      writeOffset = alignedWriteOffset + LENGTH_PREFIX_BYTES + entryLength;
-    }
-
-    return new CompactedRegion(compactedOffsets, writeOffset);
-  }
-
-  private static void writeCompactedLengthPrefixedRegion(final BytesOut sink, final MemorySegment sourceMemory,
-      final int[] sourceOffsets, final int[] compactedOffsets, final int usedSize) {
-    int writeOffset = 0;
-    for (int slot = 0; slot < sourceOffsets.length; slot++) {
-      final int sourceOffset = sourceOffsets[slot];
-      if (sourceOffset < 0) {
-        continue;
-      }
-
-      final int targetOffset = compactedOffsets[slot];
-      while (writeOffset < targetOffset) {
-        sink.writeByte((byte) 0);
-        writeOffset++;
-      }
-
-      final int entryLength = readLengthPrefix(sourceMemory, sourceOffset);
-      final int totalEntrySize = LENGTH_PREFIX_BYTES + entryLength;
-      sink.writeSegment(sourceMemory, sourceOffset, totalEntrySize);
-      writeOffset += totalEntrySize;
-    }
-
-    if (writeOffset != usedSize) {
-      throw new IllegalStateException(
-          "Compacted region size mismatch. expected=" + usedSize + ", actual=" + writeOffset);
-    }
-  }
-
-  private static int alignOffset(final int offset) {
-    return (offset + LENGTH_PREFIX_ALIGNMENT - 1) & -LENGTH_PREFIX_ALIGNMENT;
-  }
-
-  private static int readLengthPrefix(final MemorySegment sourceMemory, final int sourceOffset) {
-    if (sourceOffset < 0 || sourceOffset + LENGTH_PREFIX_BYTES > sourceMemory.byteSize()) {
-      throw new IllegalStateException("Invalid source offset for compact serialization: " + sourceOffset
-          + ", memorySize=" + sourceMemory.byteSize());
-    }
-
-    final int length = sourceMemory.get(JAVA_INT_UNALIGNED, sourceOffset);
-    if (length <= 0 || sourceOffset + LENGTH_PREFIX_BYTES + (long) length > sourceMemory.byteSize()) {
-      throw new IllegalStateException("Invalid length prefix during compact serialization. offset=" + sourceOffset
-          + ", length=" + length + ", memorySize=" + sourceMemory.byteSize());
-    }
-
-    return length;
-  }
-
-  private record CompactedRegion(int[] offsets, int usedSize) {
+    return segment.toArray(ValueLayout.JAVA_BYTE);
   }
 
   /**
    * Serialize page.
    *
    * @param ResourceConfiguration the read only page transaction
-   * @param sink {@link BytesOut} instance
-   * @param page {@link Page} implementation
+   * @param sink                  {@link BytesOut} instance
+   * @param page                  {@link Page} implementation
    */
   public abstract void serializePage(final ResourceConfiguration ResourceConfiguration, final BytesOut sink,
       final Page page, final SerializationType type);
@@ -1304,7 +1160,7 @@ public abstract void serializePage(final ResourceConfiguration ResourceConfigura
    * Deserialize page.
    *
    * @param resourceConfiguration the resource configuration
-   * @param source {@link BytesIn} instance
+   * @param source                {@link BytesIn} instance
    * @return page instance implementing the {@link Page} interface
    */
   public Page deserializePage(final ResourceConfiguration resourceConfiguration, final BytesIn source,
@@ -1315,14 +1171,13 @@ public Page deserializePage(final ResourceConfiguration resourceConfiguration, f
   /**
    * Deserialize page with optional DecompressionResult for zero-copy support.
    * 
-   * 

-   * When decompressionResult is provided, KeyValueLeafPages can take ownership of the decompression
-   * buffer and use it directly as slotMemory.
+   * 
When decompressionResult is provided, KeyValueLeafPages can take ownership
+   * of the decompression buffer and use it directly as slotMemory.
    *
    * @param resourceConfiguration the resource configuration
-   * @param source {@link BytesIn} instance
-   * @param type serialization type
-   * @param decompressionResult optional decompression result for zero-copy (may be null)
+   * @param source                {@link BytesIn} instance
+   * @param type                  serialization type
+   * @param decompressionResult   optional decompression result for zero-copy (may be null)
    * @return page instance implementing the {@link Page} interface
    */
   public abstract Page deserializePage(final ResourceConfiguration resourceConfiguration, final BytesIn source,
@@ -1337,7 +1192,7 @@ public abstract Page deserializePage(final ResourceConfiguration resourceConfigu
   public static PageKind getKind(final byte id) {
     final PageKind page = INSTANCEFORID.get(id);
     if (page == null) {
-      throw new IllegalStateException();
+      throw new IllegalStateException("Unknown PageKind id: " + id + " (0x" + Integer.toHexString(id & 0xFF) + ")");
     }
     return page;
   }
diff --git a/bundles/sirix-core/src/main/java/io/sirix/page/PageLayout.java b/bundles/sirix-core/src/main/java/io/sirix/page/PageLayout.java
new file mode 100644
index 000000000..3d9e79eb2
--- /dev/null
+++ b/bundles/sirix-core/src/main/java/io/sirix/page/PageLayout.java
@@ -0,0 +1,655 @@
+package io.sirix.page;
+
+import io.sirix.settings.Constants;
+
+import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
+
+/**
+ * Slotted page layout (PostgreSQL/LeanStore-style: Header + Bitmap + Directory + Heap) for {@link KeyValueLeafPage}.
+ *
+ * 
All page metadata, slot directory, and record data live in a single contiguous
+ * {@link MemorySegment}. In-memory format = on-disk format. ZERO conversion at commit time.
+ *
+ * 
Page Layout

+ * 
+ * Offset   Size      Field
+ * ──────── ───────── ──────────────────────
+ * 0        8         recordPageKey (long)
+ * 8        4         revision (int)
+ * 12       2         populatedCount (u16)
+ * 14       4         heapEnd (int, relative to HEAP_START)
+ * 18       4         heapUsed (int, bytes of live data)
+ * 22       1         indexType (byte)
+ * 23       1         flags (bit 0: areDeweyIDsStored, bit 1: hasFsstTable)
+ * 24       8         reserved
+ * ──────── ───────── ──────────────────────
+ * 32       128       slotBitmap (16 longs = 1024 bits)
+ * ──────── ───────── ──────────────────────
+ * 160      8192      slotDirectory (1024 × 8 bytes)
+ *                      [heapOffset:4][dataLength:3 + nodeKindId:1]
+ * ──────── ───────── ──────────────────────
+ * 8352     ...       heap (bump-allocated forward, compact varint records)
+ * 

+ *
+ * 
Slot Directory Entry (8 bytes each)

+ * 
+ * Bytes 0-3: heapOffset (int) — offset into heap region (relative to HEAP_START)
+ * Bytes 4-6: dataLength (3 bytes, unsigned) — total byte length of the record in the heap
+ * Byte 7:   nodeKindId (1 byte) — NodeKind ordinal for fast dispatch
+ * 

+ *
+ * 
Heap Record Format

+ * 
+ * [nodeKind: 1 byte]
+ * [fieldOffsetTable: fieldCount × 1 byte] — O(1) access to any field
+ * [data region: varint fields + hash + optional payload]
+ * 

+ */
+public final class PageLayout {
+
+  private PageLayout() {
+    throw new AssertionError("Utility class");
+  }
+
+  // ==================== PAGE SIZING ====================
+
+  /** Initial page allocation size (64 KB). */
+  public static final int INITIAL_PAGE_SIZE = 64 * 1024;
+
+  /** Maximum slots per page (must match Constants.NDP_NODE_COUNT). */
+  public static final int SLOT_COUNT = Constants.NDP_NODE_COUNT; // 1024
+
+  /** Slot count exponent: 2^10 = 1024 */
+  public static final int SLOT_COUNT_EXPONENT = Constants.NDP_NODE_COUNT_EXPONENT; // 10
+
+  // ==================== HEADER LAYOUT (32 bytes) ====================
+
+  /** Total header size in bytes. */
+  public static final int HEADER_SIZE = 32;
+
+  /** Offset of recordPageKey (long, 8 bytes). */
+  public static final int OFF_RECORD_PAGE_KEY = 0;
+
+  /** Offset of revision (int, 4 bytes). */
+  public static final int OFF_REVISION = 8;
+
+  /** Offset of populatedCount (unsigned short, 2 bytes). */
+  public static final int OFF_POPULATED_COUNT = 12;
+
+  /** Offset of heapEnd (int, 4 bytes) — relative to HEAP_START. */
+  public static final int OFF_HEAP_END = 14;
+
+  /** Offset of heapUsed (int, 4 bytes) — bytes of live (non-abandoned) data. */
+  public static final int OFF_HEAP_USED = 18;
+
+  /** Offset of indexType (byte, 1 byte). */
+  public static final int OFF_INDEX_TYPE = 22;
+
+  /** Offset of flags (byte, 1 byte). */
+  public static final int OFF_FLAGS = 23;
+
+  /** Offset of reserved region (8 bytes). */
+  public static final int OFF_RESERVED = 24;
+
+  // ==================== FLAGS ====================
+
+  /** Flag bit 0: DeweyIDs are stored inline in records. */
+  public static final int FLAG_DEWEY_IDS_STORED = 1;
+
+  /** Flag bit 1: FSST symbol table is present. */
+  public static final int FLAG_HAS_FSST_TABLE = 2;
+
+  // ==================== BITMAP LAYOUT (128 bytes) ====================
+
+  /** Offset where the slot bitmap starts. */
+  public static final int BITMAP_OFF = HEADER_SIZE; // 32
+
+  /** Number of 64-bit words in the bitmap. */
+  public static final int BITMAP_WORDS = 16;
+
+  /** Total size of the bitmap region in bytes. */
+  public static final int BITMAP_SIZE = BITMAP_WORDS * Long.BYTES; // 128
+
+  // ==================== SLOT DIRECTORY LAYOUT (8192 bytes) ====================
+
+  /** Offset where the slot directory starts. */
+  public static final int DIR_OFF = BITMAP_OFF + BITMAP_SIZE; // 160
+
+  /** Size of each directory entry in bytes. */
+  public static final int DIR_ENTRY_SIZE = 8;
+
+  /** Total size of the slot directory region in bytes. */
+  public static final int DIR_SIZE = SLOT_COUNT * DIR_ENTRY_SIZE; // 8192
+
+  // ==================== COMPACT DIRECTORY (on-disk only) ====================
+
+  /** Size of each compact directory entry in bytes (dataLength:3 + nodeKindId:1). */
+  public static final int COMPACT_DIR_ENTRY_SIZE = 4;
+
+  /**
+   * Pack a compact directory entry: top 3 bytes = dataLength, bottom byte = nodeKindId.
+   * Same bit layout as existing directory entry bytes 4-7.
+   */
+  public static int packCompactDirEntry(final int dataLength, final int nodeKindId) {
+    return (dataLength << 8) | (nodeKindId & 0xFF);
+  }
+
+  /** Unpack data length from a compact directory entry. */
+  public static int unpackDataLength(final int packed) {
+    return packed >>> 8;
+  }
+
+  /** Unpack node kind ID from a compact directory entry. */
+  public static int unpackNodeKindId(final int packed) {
+    return packed & 0xFF;
+  }
+
+  // ==================== HEAP LAYOUT ====================
+
+  /** Offset where the heap region starts (bump-allocated forward). */
+  public static final int HEAP_START = DIR_OFF + DIR_SIZE; // 8352
+
+  // ==================== DIRECTORY ENTRY FIELD OFFSETS ====================
+
+  /** Offset within a directory entry for the heap offset (int, 4 bytes). */
+  private static final int DIRENTRY_OFF_HEAP_OFFSET = 0;
+
+  /** Offset within a directory entry for dataLength (3 bytes) + nodeKindId (1 byte). */
+  private static final int DIRENTRY_OFF_LENGTH_AND_KIND = 4;
+
+  /** Sentinel value indicating an empty directory entry. */
+  public static final int DIR_ENTRY_EMPTY = -1;
+
+  // ==================== VALUE LAYOUTS ====================
+
+  private static final ValueLayout.OfLong JAVA_LONG_UNALIGNED =
+      ValueLayout.JAVA_LONG_UNALIGNED;
+
+  private static final ValueLayout.OfInt JAVA_INT_UNALIGNED =
+      ValueLayout.JAVA_INT.withByteAlignment(1);
+
+  private static final ValueLayout.OfShort JAVA_SHORT_UNALIGNED =
+      ValueLayout.JAVA_SHORT.withByteAlignment(1);
+
+  // ==================== HEADER ACCESSORS ====================
+
+  /** Read the recordPageKey from the page header. */
+  public static long getRecordPageKey(final MemorySegment page) {
+    return page.get(JAVA_LONG_UNALIGNED, OFF_RECORD_PAGE_KEY);
+  }
+
+  /** Write the recordPageKey into the page header. */
+  public static void setRecordPageKey(final MemorySegment page, final long key) {
+    page.set(JAVA_LONG_UNALIGNED, OFF_RECORD_PAGE_KEY, key);
+  }
+
+  /** Read the revision from the page header. */
+  public static int getRevision(final MemorySegment page) {
+    return page.get(JAVA_INT_UNALIGNED, OFF_REVISION);
+  }
+
+  /** Write the revision into the page header. */
+  public static void setRevision(final MemorySegment page, final int revision) {
+    page.set(JAVA_INT_UNALIGNED, OFF_REVISION, revision);
+  }
+
+  /** Read the populated slot count from the page header. */
+  public static int getPopulatedCount(final MemorySegment page) {
+    return Short.toUnsignedInt(page.get(JAVA_SHORT_UNALIGNED, OFF_POPULATED_COUNT));
+  }
+
+  /** Write the populated slot count into the page header. */
+  public static void setPopulatedCount(final MemorySegment page, final int count) {
+    page.set(JAVA_SHORT_UNALIGNED, OFF_POPULATED_COUNT, (short) count);
+  }
+
+  /** Read the heap end position (relative to HEAP_START) from the page header. */
+  public static int getHeapEnd(final MemorySegment page) {
+    return page.get(JAVA_INT_UNALIGNED, OFF_HEAP_END);
+  }
+
+  /** Write the heap end position (relative to HEAP_START) into the page header. */
+  public static void setHeapEnd(final MemorySegment page, final int heapEnd) {
+    page.set(JAVA_INT_UNALIGNED, OFF_HEAP_END, heapEnd);
+  }
+
+  /** Read the heap used bytes from the page header. */
+  public static int getHeapUsed(final MemorySegment page) {
+    return page.get(JAVA_INT_UNALIGNED, OFF_HEAP_USED);
+  }
+
+  /** Write the heap used bytes into the page header. */
+  public static void setHeapUsed(final MemorySegment page, final int heapUsed) {
+    page.set(JAVA_INT_UNALIGNED, OFF_HEAP_USED, heapUsed);
+  }
+
+  /** Read the index type byte from the page header. */
+  public static byte getIndexType(final MemorySegment page) {
+    return page.get(ValueLayout.JAVA_BYTE, OFF_INDEX_TYPE);
+  }
+
+  /** Write the index type byte into the page header. */
+  public static void setIndexType(final MemorySegment page, final byte indexType) {
+    page.set(ValueLayout.JAVA_BYTE, OFF_INDEX_TYPE, indexType);
+  }
+
+  /** Read the flags byte from the page header. */
+  public static byte getFlags(final MemorySegment page) {
+    return page.get(ValueLayout.JAVA_BYTE, OFF_FLAGS);
+  }
+
+  /** Write the flags byte into the page header. */
+  public static void setFlags(final MemorySegment page, final byte flags) {
+    page.set(ValueLayout.JAVA_BYTE, OFF_FLAGS, flags);
+  }
+
+  /** Check if DeweyIDs are stored (flag bit 0). */
+  public static boolean areDeweyIDsStored(final MemorySegment page) {
+    return (getFlags(page) & FLAG_DEWEY_IDS_STORED) != 0;
+  }
+
+  /** Check if FSST symbol table is present (flag bit 1). */
+  public static boolean hasFsstTable(final MemorySegment page) {
+    return (getFlags(page) & FLAG_HAS_FSST_TABLE) != 0;
+  }
+
+  // ==================== BITMAP ACCESSORS ====================
+
+  /** Read a bitmap word (one of 16 longs). */
+  public static long getBitmapWord(final MemorySegment page, final int wordIndex) {
+    return page.get(JAVA_LONG_UNALIGNED, BITMAP_OFF + ((long) wordIndex << 3));
+  }
+
+  /** Write a bitmap word (one of 16 longs). */
+  public static void setBitmapWord(final MemorySegment page, final int wordIndex, final long word) {
+    page.set(JAVA_LONG_UNALIGNED, BITMAP_OFF + ((long) wordIndex << 3), word);
+  }
+
+  /** Check if a slot is populated in the bitmap. */
+  public static boolean isSlotPopulated(final MemorySegment page, final int slotIndex) {
+    final long word = getBitmapWord(page, slotIndex >>> 6);
+    return (word & (1L << (slotIndex & 63))) != 0;
+  }
+
+  /** Set a slot's bit in the bitmap. */
+  public static void markSlotPopulated(final MemorySegment page, final int slotIndex) {
+    final int wordIndex = slotIndex >>> 6;
+    final long word = getBitmapWord(page, wordIndex);
+    setBitmapWord(page, wordIndex, word | (1L << (slotIndex & 63)));
+  }
+
+  /** Clear a slot's bit in the bitmap. */
+  public static void clearSlotPopulated(final MemorySegment page, final int slotIndex) {
+    final int wordIndex = slotIndex >>> 6;
+    final long word = getBitmapWord(page, wordIndex);
+    setBitmapWord(page, wordIndex, word & ~(1L << (slotIndex & 63)));
+  }
+
+  /**
+   * Count populated slots using Long.bitCount across all bitmap words.
+   *
+   * @return number of populated slots (0 to 1024)
+   */
+  public static int countPopulatedSlots(final MemorySegment page) {
+    int count = 0;
+    for (int i = 0; i < BITMAP_WORDS; i++) {
+      count += Long.bitCount(getBitmapWord(page, i));
+    }
+    return count;
+  }
+
+  /**
+   * Copy the entire bitmap from the page into a Java long[] array.
+   * Useful for snapshot/iteration without repeated segment access.
+   */
+  public static void copyBitmapTo(final MemorySegment page, final long[] dest) {
+    for (int i = 0; i < BITMAP_WORDS; i++) {
+      dest[i] = getBitmapWord(page, i);
+    }
+  }
+
+  /**
+   * Write the entire bitmap from a Java long[] array into the page.
+   */
+  public static void copyBitmapFrom(final MemorySegment page, final long[] src) {
+    for (int i = 0; i < BITMAP_WORDS; i++) {
+      setBitmapWord(page, i, src[i]);
+    }
+  }
+
+  // ==================== SLOT DIRECTORY ACCESSORS ====================
+
+  /**
+   * Compute the absolute byte offset of a slot directory entry.
+   */
+  public static long dirEntryOffset(final int slotIndex) {
+    return DIR_OFF + (long) slotIndex * DIR_ENTRY_SIZE;
+  }
+
+  /**
+   * Read the heap offset from a slot directory entry.
+   * Returns {@link #DIR_ENTRY_EMPTY} if the slot is not populated
+   * (caller must check bitmap first for correctness).
+   */
+  public static int getDirHeapOffset(final MemorySegment page, final int slotIndex) {
+    return page.get(JAVA_INT_UNALIGNED, dirEntryOffset(slotIndex) + DIRENTRY_OFF_HEAP_OFFSET);
+  }
+
+  /**
+   * Read the data length from a slot directory entry.
+   * The length is stored in 3 bytes (unsigned, big-endian packing within the 4-byte field).
+   * Byte layout: [dataLength_b2][dataLength_b1][dataLength_b0][nodeKindId]
+   *
+   * @return data length in bytes (0 to 16,777,215)
+   */
+  public static int getDirDataLength(final MemorySegment page, final int slotIndex) {
+    final long base = dirEntryOffset(slotIndex) + DIRENTRY_OFF_LENGTH_AND_KIND;
+    // Read 4 bytes as int, mask off the lowest byte (nodeKindId)
+    final int packed = page.get(JAVA_INT_UNALIGNED, base);
+    return packed >>> 8; // top 3 bytes = data length
+  }
+
+  /**
+   * Read the node kind ID from a slot directory entry (lowest byte of the 4-byte field).
+   *
+   * @return node kind ID (0-255)
+   */
+  public static int getDirNodeKindId(final MemorySegment page, final int slotIndex) {
+    final long base = dirEntryOffset(slotIndex) + DIRENTRY_OFF_LENGTH_AND_KIND;
+    final int packed = page.get(JAVA_INT_UNALIGNED, base);
+    return packed & 0xFF;
+  }
+
+  /**
+   * Write a complete slot directory entry.
+   *
+   * @param page       the page MemorySegment
+   * @param slotIndex  the slot index (0 to SLOT_COUNT-1)
+   * @param heapOffset offset into the heap region (relative to HEAP_START)
+   * @param dataLength total byte length of the record in the heap (0 to 16,777,215)
+   * @param nodeKindId NodeKind ordinal (0 to 255)
+   */
+  public static void setDirEntry(final MemorySegment page, final int slotIndex,
+      final int heapOffset, final int dataLength, final int nodeKindId) {
+    final long base = dirEntryOffset(slotIndex);
+    page.set(JAVA_INT_UNALIGNED, base + DIRENTRY_OFF_HEAP_OFFSET, heapOffset);
+    // Pack: top 3 bytes = dataLength, bottom byte = nodeKindId
+    final int packed = (dataLength << 8) | (nodeKindId & 0xFF);
+    page.set(JAVA_INT_UNALIGNED, base + DIRENTRY_OFF_LENGTH_AND_KIND, packed);
+  }
+
+  /**
+   * Clear a slot directory entry (set to all zeros).
+   */
+  public static void clearDirEntry(final MemorySegment page, final int slotIndex) {
+    final long base = dirEntryOffset(slotIndex);
+    page.set(JAVA_LONG_UNALIGNED, base, 0L);
+  }
+
+  // ==================== HEAP MANAGEMENT ====================
+
+  /**
+   * Compute the absolute byte offset for a heap-relative offset.
+   *
+   * @param heapRelativeOffset offset relative to HEAP_START
+   * @return absolute byte offset in the page
+   */
+  public static long heapAbsoluteOffset(final int heapRelativeOffset) {
+    return HEAP_START + (long) heapRelativeOffset;
+  }
+
+  /**
+   * Allocate space in the heap using bump allocation.
+   * Updates the heapEnd in the page header.
+   *
+   * @param page the page MemorySegment
+   * @param size number of bytes to allocate
+   * @return heap-relative offset of the allocated region
+   * @throws IllegalStateException if the page doesn't have enough space
+   */
+  public static int allocateHeap(final MemorySegment page, final int size) {
+    final int heapEnd = getHeapEnd(page);
+    final int newHeapEnd = heapEnd + size;
+
+    // Check if we've exceeded the page capacity
+    if (HEAP_START + newHeapEnd > page.byteSize()) {
+      throw new IllegalStateException(
+          "Heap overflow: need " + (HEAP_START + newHeapEnd) +
+              " bytes but page is " + page.byteSize() + " bytes");
+    }
+
+    setHeapEnd(page, newHeapEnd);
+    // Update heapUsed (for live data tracking — initially same as heapEnd)
+    setHeapUsed(page, getHeapUsed(page) + size);
+    return heapEnd;
+  }
+
+  /**
+   * Get the remaining heap capacity in bytes.
+   *
+   * @param page the page MemorySegment
+   * @return remaining bytes available for heap allocation
+   */
+  public static int heapCapacityRemaining(final MemorySegment page) {
+    return (int) page.byteSize() - HEAP_START - getHeapEnd(page);
+  }
+
+  /**
+   * Compute the heap fragmentation ratio.
+   *
+   * @return ratio of dead space to total allocated (0.0 = no fragmentation, 1.0 = all dead)
+   */
+  public static double heapFragmentation(final MemorySegment page) {
+    final int heapEnd = getHeapEnd(page);
+    if (heapEnd == 0) {
+      return 0.0;
+    }
+    final int heapUsed = getHeapUsed(page);
+    return 1.0 - ((double) heapUsed / heapEnd);
+  }
+
+  // ==================== PAGE INITIALIZATION ====================
+
+  /**
+   * Initialize a fresh page MemorySegment with default header values.
+   * Zeroes the bitmap and directory regions.
+   *
+   * @param page           the page MemorySegment (must be at least INITIAL_PAGE_SIZE)
+   * @param recordPageKey  the page key
+   * @param revision       the revision number
+   * @param indexType      the index type byte
+   * @param areDeweyIDs    whether DeweyIDs will be stored
+   */
+  public static void initializePage(final MemorySegment page, final long recordPageKey,
+      final int revision, final byte indexType, final boolean areDeweyIDs) {
+    // Clear header + bitmap + directory (all zeros)
+    page.asSlice(0, HEAP_START).fill((byte) 0);
+
+    // Write header fields
+    setRecordPageKey(page, recordPageKey);
+    setRevision(page, revision);
+    setPopulatedCount(page, 0);
+    setHeapEnd(page, 0);
+    setHeapUsed(page, 0);
+    setIndexType(page, indexType);
+    byte flags = 0;
+    if (areDeweyIDs) {
+      flags |= (byte) FLAG_DEWEY_IDS_STORED;
+    }
+    setFlags(page, flags);
+  }
+
+  // ==================== PAGE RESIZING ====================
+
+  /**
+   * Compute the new page size for growth (doubling strategy).
+   *
+   * @param currentSize the current page size
+   * @param needed      the minimum total size needed
+   * @return the new page size (at least needed, typically 2x current)
+   */
+  public static int computeGrowthSize(final int currentSize, final int needed) {
+    int newSize = currentSize;
+    while (newSize < needed) {
+      newSize <<= 1; // double
+    }
+    return newSize;
+  }
+
+  // ==================== RECORD OFFSET TABLE ====================
+
+  /**
+   * Read a field offset from a record's offset table.
+   * The offset table starts at recordBase + 1 (after the nodeKind byte).
+   *
+   * @param page         the page MemorySegment
+   * @param recordBase   absolute byte offset of the record start
+   * @param fieldIndex   the field index (0 to fieldCount-1)
+   * @return the field offset (0-255) relative to the data region start
+   */
+  public static int readFieldOffset(final MemorySegment page, final long recordBase,
+      final int fieldIndex) {
+    return page.get(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex) & 0xFF;
+  }
+
+  /**
+   * Write a field offset into a record's offset table.
+   *
+   * @param page        the page MemorySegment
+   * @param recordBase  absolute byte offset of the record start
+   * @param fieldIndex  the field index (0 to fieldCount-1)
+   * @param offset      the field offset (0-255) relative to the data region start
+   */
+  public static void writeFieldOffset(final MemorySegment page, final long recordBase,
+      final int fieldIndex, final int offset) {
+    page.set(ValueLayout.JAVA_BYTE, recordBase + 1 + fieldIndex, (byte) offset);
+  }
+
+  /**
+   * Compute the absolute offset of the data region for a record.
+   * Data region starts after: [nodeKind: 1 byte] + [offset table: fieldCount bytes].
+   *
+   * @param recordBase absolute byte offset of the record start
+   * @param fieldCount number of fields in the offset table
+   * @return absolute byte offset where the data region begins
+   */
+  public static long dataRegionStart(final long recordBase, final int fieldCount) {
+    return recordBase + 1 + fieldCount;
+  }
+
+  /**
+   * Read the nodeKind byte from a record in the heap.
+   *
+   * @param page       the page MemorySegment
+   * @param recordBase absolute byte offset of the record start
+   * @return the nodeKind byte
+   */
+  public static byte readRecordKind(final MemorySegment page, final long recordBase) {
+    return page.get(ValueLayout.JAVA_BYTE, recordBase);
+  }
+
+  /**
+   * Write the nodeKind byte for a record in the heap.
+   *
+   * @param page       the page MemorySegment
+   * @param recordBase absolute byte offset of the record start
+   * @param kindId     the nodeKind byte
+   */
+  public static void writeRecordKind(final MemorySegment page, final long recordBase,
+      final byte kindId) {
+    page.set(ValueLayout.JAVA_BYTE, recordBase, kindId);
+  }
+
+  // ==================== DEWEY ID INLINE SUPPORT ====================
+
+  /**
+   * Size of the DeweyID length trailer appended to each heap allocation
+   * when FLAG_DEWEY_IDS_STORED is set. Unsigned 16-bit (0-65535).
+   */
+  public static final int DEWEY_ID_TRAILER_SIZE = 2;
+
+  /**
+   * Read the DeweyID length from the trailer at the end of a slot's heap allocation.
+   * Returns 0 if DeweyIDs are not stored or the slot has no DeweyID.
+   *
+   * @param page      the page MemorySegment
+   * @param slotIndex the slot index
+   * @return DeweyID data length in bytes (0 if none)
+   */
+  public static int getDeweyIdLength(final MemorySegment page, final int slotIndex) {
+    if (!areDeweyIDsStored(page)) {
+      return 0;
+    }
+    final int dataLength = getDirDataLength(page, slotIndex);
+    if (dataLength < DEWEY_ID_TRAILER_SIZE) {
+      return 0;
+    }
+    final int heapOffset = getDirHeapOffset(page, slotIndex);
+    final long trailerPos = heapAbsoluteOffset(heapOffset) + dataLength - DEWEY_ID_TRAILER_SIZE;
+    return Short.toUnsignedInt(page.get(JAVA_SHORT_UNALIGNED, trailerPos));
+  }
+
+  /**
+   * Get the record-only data length (excluding DeweyID data and trailer).
+   * When DeweyIDs are not stored, this equals the full dataLength.
+   *
+   * @param page      the page MemorySegment
+   * @param slotIndex the slot index
+   * @return record-only byte length
+   */
+  public static int getRecordOnlyLength(final MemorySegment page, final int slotIndex) {
+    final int dataLength = getDirDataLength(page, slotIndex);
+    if (!areDeweyIDsStored(page)) {
+      return dataLength;
+    }
+    if (dataLength < DEWEY_ID_TRAILER_SIZE) {
+      return dataLength;
+    }
+    final int deweyIdLen = getDeweyIdLength(page, slotIndex);
+    return dataLength - deweyIdLen - DEWEY_ID_TRAILER_SIZE;
+  }
+
+  /**
+   * Get the DeweyID data from a slot's heap allocation as a MemorySegment slice.
+   * Returns null if the slot has no DeweyID.
+   *
+   * @param page      the page MemorySegment
+   * @param slotIndex the slot index
+   * @return MemorySegment slice containing DeweyID bytes, or null
+   */
+  public static MemorySegment getDeweyId(final MemorySegment page, final int slotIndex) {
+    final int deweyIdLen = getDeweyIdLength(page, slotIndex);
+    if (deweyIdLen == 0) {
+      return null;
+    }
+    final int dataLength = getDirDataLength(page, slotIndex);
+    final int heapOffset = getDirHeapOffset(page, slotIndex);
+    // DeweyID data is between record data and the 2-byte trailer
+    final long deweyIdStart = heapAbsoluteOffset(heapOffset) + dataLength
+        - DEWEY_ID_TRAILER_SIZE - deweyIdLen;
+    return page.asSlice(deweyIdStart, deweyIdLen);
+  }
+
+  /**
+   * Write a 2-byte DeweyID length trailer (u16) at the end of a heap allocation.
+   *
+   * @param page       the page MemorySegment
+   * @param absEnd     absolute byte position of the allocation end (where trailer goes)
+   * @param deweyIdLen length of the DeweyID data (0 if none)
+   */
+  public static void writeDeweyIdTrailer(final MemorySegment page, final long absEnd,
+      final int deweyIdLen) {
+    page.set(JAVA_SHORT_UNALIGNED, absEnd - DEWEY_ID_TRAILER_SIZE, (short) deweyIdLen);
+  }
+
+  // ==================== COMPACTION ====================
+
+  /**
+   * Check whether the heap needs compaction.
+   * Returns true when dead space exceeds the compaction threshold (25%).
+   */
+  public static boolean needsCompaction(final MemorySegment page) {
+    return heapFragmentation(page) > 0.25;
+  }
+}
diff --git a/bundles/sirix-core/src/main/java/io/sirix/page/SlotOffsetCodec.java b/bundles/sirix-core/src/main/java/io/sirix/page/SlotOffsetCodec.java
deleted file mode 100644
index 009977289..000000000
--- a/bundles/sirix-core/src/main/java/io/sirix/page/SlotOffsetCodec.java
+++ /dev/null
@@ -1,371 +0,0 @@
-/*
- * Copyright (c) 2023, Sirix Contributors
- *
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *     * Redistributions of source code must retain the above copyright
- *       notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above copyright
- *       notice, this list of conditions and the following disclaimer in the
- *       documentation and/or other materials provided with the distribution.
- *     * Neither the name of the  nor the
- *       names of its contributors may be used to endorse or promote products
- *       derived from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
- * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED. IN NO EVENT SHALL  BE LIABLE FOR ANY
- * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
- * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
- * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
- * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package io.sirix.page;
-
-import io.sirix.node.BytesIn;
-import io.sirix.node.BytesOut;
-import io.sirix.settings.Constants;
-
-import java.util.Arrays;
-import java.util.BitSet;
-
-// ThreadLocal buffers for HFT-level performance (avoid allocation on hot path)
-
-/**
- * Codec for compressing slot offset arrays using bit-packing.
- *
- * 

- * This compression technique is inspired by best practices from DuckDB, RocksDB, and Apache
- * Parquet. It achieves significant space savings compared to raw int[1024] arrays:
- * 

- * 
    
- * 
  • Sparse pages (10% full): ~95% savings
    • 
- * 
  • Realistic pages (80% full): ~50% savings
    • 
- * 
  • Full pages: ~50% savings
    • 
- * 

- *
- * 
Format

- * 
- * 
- * ┌─────────────────────────────────────────────────────────────────┐
- * │                    Compressed Slot Offsets                       │
- * ├─────────────────────────────────────────────────────────────────┤
- * │ Presence Bitmap   │ Bit Width │ Bit-Packed Offsets              │
- * │ (BitSet ~128B)    │ (1 byte)  │ (N×bitWidth bits)               │
- * └─────────────────────────────────────────────────────────────────┘
- * 

- *
- * 
Algorithm

- * 
    
- * 
  1. Build a presence bitmap indicating which slots are populated (offset >= 0)
    2. 
- * 
  2. Extract populated offsets in slot order
    3. 
- * 
  3. Determine minimum bit width needed to represent max offset
    4. 
- * 
  4. Bit-pack all offsets using the computed bit width
    5. 
- * 

- *
- * 

- * Note: Delta encoding is not used because slot offsets are not guaranteed to be monotonically
- * increasing when iterated in slot order.
- * 

- *
- * @author Johannes Lichtenberger
- */
-public final class SlotOffsetCodec {
-
-  /**
-   * ThreadLocal buffer for reading packed bytes during decode. Sized to handle worst case: 1024 slots
-   * × 32 bits = 4096 bytes. Avoids allocation on every page read (critical read path).
-   */
-  private static final ThreadLocal DECODE_BUFFER =
-      ThreadLocal.withInitial(() -> new byte[Constants.NDP_NODE_COUNT * 4]); // 4KB max
-
-  /**
-   * ThreadLocal buffer for writing packed bytes during encode. Avoids allocation on every page write.
-   */
-  private static final ThreadLocal ENCODE_BUFFER =
-      ThreadLocal.withInitial(() -> new byte[Constants.NDP_NODE_COUNT * 4]); // 4KB max
-
-  /**
-   * ThreadLocal BitSet for encode operations. Reused across calls to avoid allocation.
-   */
-  private static final ThreadLocal ENCODE_BITSET =
-      ThreadLocal.withInitial(() -> new BitSet(Constants.NDP_NODE_COUNT));
-
-  /**
-   * ThreadLocal array for populated offsets during encode.
-   */
-  private static final ThreadLocal ENCODE_OFFSETS =
-      ThreadLocal.withInitial(() -> new int[Constants.NDP_NODE_COUNT]);
-
-  private SlotOffsetCodec() {
-    throw new AssertionError("May not be instantiated!");
-  }
-
-  /**
-   * Encode slot offsets using bit-packing.
-   *
-   * 

-   * Format: [presence bitmap][bitWidth (1B)][bit-packed offsets]
-   * 

-   *
-   * @param sink the output to write compressed data to
-   * @param slotOffsets the slot offset array (length must be Constants.NDP_NODE_COUNT)
-   * @param lastSlotIndex unused, kept for API compatibility
-   * @throws NullPointerException if sink or slotOffsets is null
-   * @throws IllegalArgumentException if slotOffsets.length != Constants.NDP_NODE_COUNT
-   */
-  public static void encode(final BytesOut sink, final int[] slotOffsets, final int lastSlotIndex) {
-    if (sink == null) {
-      throw new NullPointerException("sink must not be null");
-    }
-    if (slotOffsets == null) {
-      throw new NullPointerException("slotOffsets must not be null");
-    }
-    if (slotOffsets.length != Constants.NDP_NODE_COUNT) {
-      throw new IllegalArgumentException(
-          "slotOffsets.length must be " + Constants.NDP_NODE_COUNT + " but was " + slotOffsets.length);
-    }
-
-    // 1. Build presence bitmap by scanning all slots (reuse ThreadLocal BitSet)
-    // Note: lastSlotIndex tracks the slot with largest OFFSET, not highest slot NUMBER
-    // So we must scan all slots to find all populated ones
-    final BitSet presence = ENCODE_BITSET.get();
-    presence.clear(); // Reset for reuse
-    int populatedCount = 0;
-
-    for (int i = 0; i < Constants.NDP_NODE_COUNT; i++) {
-      if (slotOffsets[i] >= 0) {
-        presence.set(i);
-        populatedCount++;
-      }
-    }
-
-    SerializationType.serializeBitSet(sink, presence);
-
-    if (populatedCount == 0) {
-      return; // Empty page - just bitmap is sufficient
-    }
-
-    // 2. Extract populated offsets in slot order and find max (reuse ThreadLocal array)
-    final int[] populatedOffsets = ENCODE_OFFSETS.get();
-    int idx = 0;
-    int maxOffset = 0;
-    for (int i = presence.nextSetBit(0); i >= 0; i = presence.nextSetBit(i + 1)) {
-      final int offset = slotOffsets[i];
-      populatedOffsets[idx++] = offset;
-      maxOffset = Math.max(maxOffset, offset);
-    }
-
-    // 3. Determine bit width from max offset (not deltas - offsets aren't monotonic)
-    int bitWidth = 32 - Integer.numberOfLeadingZeros(maxOffset);
-    if (bitWidth == 0) {
-      bitWidth = 1; // Minimum 1 bit
-    }
-
-    sink.writeByte((byte) bitWidth);
-
-    // 4. Bit-pack all offsets directly (pass count since array may be larger)
-    writeBitPacked(sink, populatedOffsets, populatedCount, bitWidth);
-  }
-
-  /**
-   * Decode compressed slot offsets back to int[1024] array.
-   *
-   * 

-   * Empty slots are marked with -1.
-   * 

-   * 

-   * Optimized to avoid intermediate array allocation by reading directly into sparse result.
-   * 

-   *
-   * @param source the input to read compressed data from
-   * @return the decoded slot offset array of length Constants.NDP_NODE_COUNT
-   * @throws NullPointerException if source is null
-   */
-  public static int[] decode(final BytesIn source) {
-    if (source == null) {
-      throw new NullPointerException("source must not be null");
-    }
-
-    final int[] slotOffsets = new int[Constants.NDP_NODE_COUNT];
-    Arrays.fill(slotOffsets, -1);
-
-    // 1. Read presence bitmap
-    final BitSet presence = SerializationType.deserializeBitSet(source);
-    final int populatedCount = presence.cardinality();
-
-    if (populatedCount == 0) {
-      return slotOffsets; // Empty page
-    }
-
-    // 2. Read bit width and unpack directly into sparse result array
-    final int bitWidth = source.readByte() & 0xFF;
-    readBitPackedDirect(source, presence, slotOffsets, populatedCount, bitWidth);
-
-    return slotOffsets;
-  }
-
-  /**
-   * Pack integers using exactly bitWidth bits each.
-   *
-   * 

-   * Values are packed in little-endian bit order within each byte.
-   * 

-   *
-   * @param sink the output to write packed data to
-   * @param values the integer values to pack (all values used)
-   * @param bitWidth the number of bits to use per value (1-32)
-   */
-  static void writeBitPacked(final BytesOut sink, final int[] values, final int bitWidth) {
-    writeBitPacked(sink, values, values.length, bitWidth);
-  }
-
-  /**
-   * Pack integers using exactly bitWidth bits each.
-   *
-   * 

-   * Values are packed in little-endian bit order within each byte.
-   * 

-   * 

-   * Uses ThreadLocal buffer to avoid allocation on hot path.
-   * 

-   *
-   * @param sink the output to write packed data to
-   * @param values the integer values to pack
-   * @param count the number of values to pack from the array
-   * @param bitWidth the number of bits to use per value (1-32)
-   */
-  static void writeBitPacked(final BytesOut sink, final int[] values, final int count, final int bitWidth) {
-    if (count == 0) {
-      return;
-    }
-
-    // Calculate total bytes needed
-    final int totalBits = count * bitWidth;
-    final int totalBytes = (totalBits + 7) / 8;
-
-    // Reuse ThreadLocal buffer to avoid allocation
-    final byte[] packed = ENCODE_BUFFER.get();
-    Arrays.fill(packed, 0, totalBytes, (byte) 0); // Clear only needed portion
-    int bitPos = 0;
-
-    for (int i = 0; i < count; i++) {
-      final int value = values[i];
-      // Write 'bitWidth' bits of value starting at bitPos
-      final int bytePos = bitPos / 8;
-      final int bitOffset = bitPos % 8;
-
-      // Handle value spanning multiple bytes (up to 5 bytes for 32-bit values)
-      final long shifted = ((long) value) << bitOffset;
-      final int bytesNeeded = (bitOffset + bitWidth + 7) / 8;
-
-      for (int b = 0; b < bytesNeeded && bytePos + b < totalBytes; b++) {
-        packed[bytePos + b] |= (byte) (shifted >>> (b * 8));
-      }
-      bitPos += bitWidth;
-    }
-
-    sink.write(packed, 0, totalBytes);
-  }
-
-  /**
-   * Unpack integers from bitWidth-bit packed format directly into sparse result array.
-   * 

-   * Optimized to avoid intermediate array allocation by writing directly to the positions indicated
-   * by the presence BitSet.
-   * 

-   *
-   * @param source the input to read packed data from
-   * @param presence BitSet indicating which slots are populated
-   * @param result the sparse result array to write values into
-   * @param count the number of integers to unpack
-   * @param bitWidth the number of bits per value (1-32)
-   */
-  private static void readBitPackedDirect(final BytesIn source, final BitSet presence, final int[] result,
-      final int count, final int bitWidth) {
-    if (count == 0) {
-      return;
-    }
-
-    final int totalBits = count * bitWidth;
-    final int totalBytes = (totalBits + 7) / 8;
-
-    // Reuse ThreadLocal buffer to avoid allocation on hot path
-    final byte[] packed = DECODE_BUFFER.get();
-    source.read(packed, 0, totalBytes);
-
-    int bitPos = 0;
-    final int mask = (bitWidth == 32)
-        ? -1
-        : (1 << bitWidth) - 1;
-
-    // Iterate through presence bits and write directly to result positions
-    for (int slotIndex = presence.nextSetBit(0); slotIndex >= 0; slotIndex = presence.nextSetBit(slotIndex + 1)) {
-      final int bytePos = bitPos / 8;
-      final int bitOffset = bitPos % 8;
-
-      // Read up to 5 bytes to handle 32-bit values spanning byte boundaries
-      long accumulated = 0;
-      for (int b = 0; b < 5 && bytePos + b < totalBytes; b++) {
-        accumulated |= ((long) (packed[bytePos + b] & 0xFF)) << (b * 8);
-      }
-
-      result[slotIndex] = (int) ((accumulated >>> bitOffset) & mask);
-      bitPos += bitWidth;
-    }
-  }
-
-  /**
-   * Unpack integers from bitWidth-bit packed format.
-   * 

-   * Uses ThreadLocal buffer to avoid allocation on hot path.
-   * 

-   *
-   * @param source the input to read packed data from
-   * @param count the number of integers to unpack
-   * @param bitWidth the number of bits per value (1-32)
-   * @return the unpacked integer values
-   */
-  static int[] readBitPacked(final BytesIn source, final int count, final int bitWidth) {
-    if (count == 0) {
-      return new int[0];
-    }
-
-    final int totalBits = count * bitWidth;
-    final int totalBytes = (totalBits + 7) / 8;
-
-    // Reuse ThreadLocal buffer to avoid allocation
-    final byte[] packed = DECODE_BUFFER.get();
-    source.read(packed, 0, totalBytes);
-
-    final int[] values = new int[count];
-    int bitPos = 0;
-    final int mask = (bitWidth == 32)
-        ? -1
-        : (1 << bitWidth) - 1;
-
-    for (int i = 0; i < count; i++) {
-      final int bytePos = bitPos / 8;
-      final int bitOffset = bitPos % 8;
-
-      // Read up to 5 bytes to handle 32-bit values spanning byte boundaries
-      long accumulated = 0;
-      for (int b = 0; b < 5 && bytePos + b < totalBytes; b++) {
-        accumulated |= ((long) (packed[bytePos + b] & 0xFF)) << (b * 8);
-      }
-
-      values[i] = (int) ((accumulated >>> bitOffset) & mask);
-      bitPos += bitWidth;
-    }
-
-    return values;
-  }
-}
-
-
diff --git a/bundles/sirix-core/src/main/java/io/sirix/settings/VersioningType.java b/bundles/sirix-core/src/main/java/io/sirix/settings/VersioningType.java
index 9b725b048..03cf621a0 100644
--- a/bundles/sirix-core/src/main/java/io/sirix/settings/VersioningType.java
+++ b/bundles/sirix-core/src/main/java/io/sirix/settings/VersioningType.java
@@ -29,6 +29,7 @@
 import io.sirix.page.BitmapChunkPage;
 import io.sirix.page.HOTLeafPage;
 import io.sirix.page.KeyValueLeafPage;
+import io.sirix.page.PageLayout;
 import io.sirix.page.PageFragmentKeyImpl;
 import io.sirix.page.PageReference;
 import io.sirix.page.interfaces.KeyValuePage;
@@ -37,7 +38,6 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.lang.foreign.MemorySegment;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
@@ -61,18 +61,23 @@ public > T combineRecordPages(fi
         final @NonNegative int revToRestore, final StorageEngineReader storageEngineReader) {
       assert pages.size() == 1 : "Only one version of the page!";
       var firstPage = pages.getFirst();
-      T completePage = firstPage.newInstance(firstPage.getPageKey(), firstPage.getIndexType(), storageEngineReader);
+      T completePage =  firstPage.newInstance(firstPage.getPageKey(), firstPage.getIndexType(), storageEngineReader);
 
-      if (firstPage instanceof KeyValueLeafPage firstKvp) {
-        copyAllSlotsFromBitmap(firstPage, completePage, firstKvp.getSlotBitmap(), null);
-      } else {
-        for (int i = 0; i < firstPage.size(); i++) {
-          var slot = firstPage.getSlot(i);
-          if (slot == null) {
-            continue;
-          }
-          copySlotAndDeweyId(firstPage, completePage, i, slot);
+      final KeyValueLeafPage srcKvl = (KeyValueLeafPage) firstPage;
+      final KeyValueLeafPage dstKvl = (KeyValueLeafPage) completePage;
+      dstKvl.ensureSlottedPage();
+
+      // Use populatedSlots() for O(k) bitmap-driven iteration
+      final int[] populated = srcKvl.populatedSlots();
+      for (final int i : populated) {
+        var slot = firstPage.getSlot(i);
+
+        if (slot == null) {
+          continue;
         }
+
+        dstKvl.setSlotWithNodeKind(slot, i, srcKvl.getSlotNodeKindId(i));
+        completePage.setDeweyId(firstPage.getDeweyId(i), i);
       }
 
       // Propagate FSST symbol table for string compression
@@ -93,17 +98,19 @@ public > PageContainer combineRe
       // FULL versioning stores complete pages, so both complete and modified can be the same
       final T modifiedPage = firstPage.newInstance(recordPageKey, firstPage.getIndexType(), storageEngineReader);
 
-      // Copy data once (not twice)
-      if (firstPage instanceof KeyValueLeafPage firstKvp) {
-        copyAllSlotsFromBitmap(firstPage, modifiedPage, firstKvp.getSlotBitmap(), null);
-      } else {
-        for (int i = 0; i < firstPage.size(); i++) {
-          var slot = firstPage.getSlot(i);
-          if (slot == null) {
-            continue;
-          }
-          copySlotAndDeweyId(firstPage, modifiedPage, i, slot);
+      final KeyValueLeafPage srcKvl = (KeyValueLeafPage) firstPage;
+      final KeyValueLeafPage dstKvl = (KeyValueLeafPage) modifiedPage;
+      dstKvl.ensureSlottedPage();
+
+      // Copy data once (not twice) - use populatedSlots() for O(k) iteration
+      final int[] populated = srcKvl.populatedSlots();
+      for (final int i : populated) {
+        var slot = firstPage.getSlot(i);
+        if (slot == null) {
+          continue;
         }
+        dstKvl.setSlotWithNodeKind(slot, i, srcKvl.getSlotNodeKindId(i));
+        modifiedPage.setDeweyId(firstPage.getDeweyId(i), i);
       }
 
       // Propagate FSST symbol table from the original page
@@ -119,7 +126,7 @@ public > PageContainer combineRe
 
     @Override
     public int[] getRevisionRoots(@NonNegative int previousRevision, @NonNegative int revsToRestore) {
-      return new int[] {previousRevision};
+      return new int[] { previousRevision };
     }
   },
 
@@ -137,9 +144,7 @@ public > T combineRecordPages(fi
       final T pageToReturn = firstPage.newInstance(recordPageKey, firstPage.getIndexType(), storageEngineReader);
 
       final T latest = pages.get(0);
-      final T fullDump = pages.size() == 1
-          ? pages.get(0)
-          : pages.get(1);
+      final T fullDump = pages.size() == 1 ? pages.get(0) : pages.get(1);
 
       assert latest.getPageKey() == recordPageKey;
       assert fullDump.getPageKey() == recordPageKey;
@@ -147,9 +152,18 @@ public > T combineRecordPages(fi
       // Use bitmap iteration for O(k) instead of O(1024)
       final KeyValueLeafPage latestKvp = (KeyValueLeafPage) latest;
       final KeyValueLeafPage returnKvp = (KeyValueLeafPage) pageToReturn;
+      returnKvp.ensureSlottedPage();
 
       // Copy all populated slots from latest page
-      copyAllSlotsFromBitmap(firstPage, pageToReturn, latestKvp.getSlotBitmap(), null);
+      final int[] latestSlots = latestKvp.populatedSlots();
+      for (int i = 0; i < latestSlots.length; i++) {
+        final int offset = latestSlots[i];
+        returnKvp.setSlotWithNodeKind(firstPage.getSlot(offset), offset, latestKvp.getSlotNodeKindId(offset));
+        var deweyId = firstPage.getDeweyId(offset);
+        if (deweyId != null) {
+          pageToReturn.setDeweyId(deweyId, offset);
+        }
+      }
 
       // Copy references from latest
       for (final Map.Entry entry : latest.referenceEntrySet()) {
@@ -162,7 +176,22 @@ public > T combineRecordPages(fi
         final long[] filledBitmap = returnKvp.getSlotBitmap();
 
         // Use bitmap iteration for O(k) on fullDump
-        copyMissingSlotsFromBitmap(fullDump, pageToReturn, fullDumpKvp.getSlotBitmap(), filledBitmap, null);
+        final int[] fullDumpSlots = fullDumpKvp.populatedSlots();
+        for (int i = 0; i < fullDumpSlots.length; i++) {
+          final int offset = fullDumpSlots[i];
+          // Check if slot already filled using bitmap (O(1))
+          if ((filledBitmap[offset >>> 6] & (1L << (offset & 63))) != 0) {
+            continue;  // Already filled from latest
+          }
+
+          var recordData = fullDump.getSlot(offset);
+          returnKvp.setSlotWithNodeKind(recordData, offset, fullDumpKvp.getSlotNodeKindId(offset));
+
+          var deweyId = fullDump.getDeweyId(offset);
+          if (deweyId != null) {
+            pageToReturn.setDeweyId(deweyId, offset);
+          }
+        }
 
         // Fill reference gaps
         for (final Entry entry : fullDump.referenceEntrySet()) {
@@ -191,33 +220,44 @@ public > PageContainer combineRe
       final int revision = storageEngineReader.getUberPage().getRevisionNumber();
 
       // Update pageFragments on original reference
-      final List pageFragmentKeys = List.of(new PageFragmentKeyImpl(firstPage.getRevision(),
-          reference.getKey(), (int) storageEngineReader.getDatabaseId(), (int) storageEngineReader.getResourceId()));
+      final List pageFragmentKeys = List.of(new PageFragmentKeyImpl(
+          firstPage.getRevision(), 
+          reference.getKey(),
+          (int) storageEngineReader.getDatabaseId(),
+          (int) storageEngineReader.getResourceId()));
       reference.setPageFragments(pageFragmentKeys);
 
       final T completePage = firstPage.newInstance(recordPageKey, firstPage.getIndexType(), storageEngineReader);
       final T modifiedPage = firstPage.newInstance(recordPageKey, firstPage.getIndexType(), storageEngineReader);
 
-      // DIAGNOSTIC
-      if (KeyValueLeafPage.DEBUG_MEMORY_LEAKS && recordPageKey == 0) {
-        LOGGER.debug("DIFFERENTIAL combineForMod created: complete=" + System.identityHashCode(completePage)
-            + ", modified=" + System.identityHashCode(modifiedPage));
-      }
-
       final T latest = firstPage;
-      final T fullDump = pages.size() == 1
-          ? firstPage
-          : pages.get(1);
+      final T fullDump = pages.size() == 1 ? firstPage : pages.get(1);
       final boolean isFullDumpRevision = revision % revToRestore == 0;
 
       // Use bitmap iteration for O(k) instead of O(1024)
       final KeyValueLeafPage latestKvp = (KeyValueLeafPage) latest;
       final KeyValueLeafPage completeKvp = (KeyValueLeafPage) completePage;
       final KeyValueLeafPage modifiedKvp = (KeyValueLeafPage) modifiedPage;
+      completeKvp.ensureSlottedPage();
+      modifiedKvp.ensureSlottedPage();
 
       // Copy all populated slots from latest to completePage using bitmap iteration
       // For modifiedPage: use lazy copy - mark for preservation, actual copy deferred to commit time
-      copyAllSlotsFromBitmap(firstPage, completePage, latestKvp.getSlotBitmap(), modifiedKvp);
+      final int[] latestSlots = latestKvp.populatedSlots();
+      for (int i = 0; i < latestSlots.length; i++) {
+        final int offset = latestSlots[i];
+        var recordData = firstPage.getSlot(offset);
+        var deweyId = firstPage.getDeweyId(offset);
+
+        completeKvp.setSlotWithNodeKind(recordData, offset, latestKvp.getSlotNodeKindId(offset));
+        if (deweyId != null) {
+          completePage.setDeweyId(deweyId, offset);
+        }
+        
+        // LAZY COPY: Mark slot for preservation instead of copying
+        // Actual copy from completePage happens in addReferences() if records[offset] == null
+        modifiedKvp.markSlotForPreservation(offset);
+      }
 
       // Copy references from latest
       for (final Map.Entry entry : latest.referenceEntrySet()) {
@@ -229,12 +269,30 @@ public > PageContainer combineRe
       if (completeKvp.populatedSlotCount() < Constants.NDP_NODE_COUNT && pages.size() == 2) {
         final KeyValueLeafPage fullDumpKvp = (KeyValueLeafPage) fullDump;
         final long[] filledBitmap = completeKvp.getSlotBitmap();
-
+        
         // Use bitmap iteration on fullDump
-        copyMissingSlotsFromBitmap(fullDump, completePage, fullDumpKvp.getSlotBitmap(), filledBitmap, isFullDumpRevision
-            ? modifiedKvp
-            : null);
+        final int[] fullDumpSlots = fullDumpKvp.populatedSlots();
+        for (int j = 0; j < fullDumpSlots.length; j++) {
+          final int offset = fullDumpSlots[j];
+          // Check if slot already filled using bitmap (O(1))
+          if ((filledBitmap[offset >>> 6] & (1L << (offset & 63))) != 0) {
+            continue;  // Already filled from latest
+          }
+          
+          var recordData = fullDump.getSlot(offset);
+          var deweyId = fullDump.getDeweyId(offset);
+
+          completeKvp.setSlotWithNodeKind(recordData, offset, fullDumpKvp.getSlotNodeKindId(offset));
+          if (deweyId != null) {
+            completePage.setDeweyId(deweyId, offset);
+          }
 
+          if (isFullDumpRevision) {
+            // LAZY COPY: Mark slot for preservation instead of copying
+            modifiedKvp.markSlotForPreservation(offset);
+          }
+        }
+        
         // Fill reference gaps from fullDump
         for (final Map.Entry entry : fullDump.referenceEntrySet()) {
           if (completePage.getPageReference(entry.getKey()) == null) {
@@ -255,7 +313,7 @@ public > PageContainer combineRe
       modifiedKvp.setCompletePageRef(completeKvp);
 
       final var pageContainer = PageContainer.getInstance(completePage, modifiedPage);
-      log.put(reference, pageContainer); // TIL will remove from caches before mutating
+      log.put(reference, pageContainer);  // TIL will remove from caches before mutating
       return pageContainer;
     }
 
@@ -264,9 +322,9 @@ public int[] getRevisionRoots(@NonNegative int previousRevision, @NonNegative in
       final int revisionsToRestore = previousRevision % revsToRestore;
       final int lastFullDump = previousRevision - revisionsToRestore;
       if (lastFullDump == previousRevision) {
-        return new int[] {lastFullDump};
+        return new int[] { lastFullDump };
       } else {
-        return new int[] {previousRevision, lastFullDump};
+        return new int[] { previousRevision, lastFullDump };
       }
     }
   },
@@ -287,11 +345,12 @@ public > T combineRecordPages(fi
       // Track which slots are already filled using bitmap from pageToReturn
       // This enables O(k) iteration instead of O(1024)
       final KeyValueLeafPage returnPage = (KeyValueLeafPage) pageToReturn;
+      returnPage.ensureSlottedPage();
       final long[] filledBitmap = returnPage.getSlotBitmap();
-
+      
       // Track slot count incrementally - CRITICAL: don't call populatedSlotCount() in loop
       int filledSlotCount = 0;
-
+      
       for (final T page : pages) {
         assert page.getPageKey() == recordPageKey;
         if (filledSlotCount == Constants.NDP_NODE_COUNT) {
@@ -300,8 +359,28 @@ public > T combineRecordPages(fi
 
         // Use bitmap iteration for O(k) instead of O(1024)
         final KeyValueLeafPage kvPage = (KeyValueLeafPage) page;
-        filledSlotCount = copyMissingSlotsFromBitmapUntilFull(page, pageToReturn, kvPage.getSlotBitmap(), filledBitmap,
-            filledSlotCount, null);
+        final int[] populatedSlots = kvPage.populatedSlots();
+        
+        for (final int offset : populatedSlots) {
+          // Check if slot already filled using bitmap (O(1))
+          if ((filledBitmap[offset >>> 6] & (1L << (offset & 63))) != 0) {
+            continue;  // Already filled from newer fragment
+          }
+
+          final var recordData = page.getSlot(offset);
+          returnPage.setSlotWithNodeKind(recordData, offset, kvPage.getSlotNodeKindId(offset));
+          filledBitmap[offset >>> 6] |= (1L << (offset & 63));
+          filledSlotCount++;
+
+          final var deweyId = page.getDeweyId(offset);
+          if (deweyId != null) {
+            pageToReturn.setDeweyId(deweyId, offset);
+          }
+
+          if (filledSlotCount == Constants.NDP_NODE_COUNT) {
+            break;
+          }
+        }
 
         if (filledSlotCount < Constants.NDP_NODE_COUNT) {
           for (final Entry entry : page.referenceEntrySet()) {
@@ -329,10 +408,13 @@ public > PageContainer combineRe
       final T firstPage = pages.getFirst();
       final long recordPageKey = firstPage.getPageKey();
       final var previousPageFragmentKeys = new ArrayList(reference.getPageFragments().size() + 1);
-      previousPageFragmentKeys.add(new PageFragmentKeyImpl(firstPage.getRevision(), reference.getKey(),
-          (int) storageEngineReader.getDatabaseId(), (int) storageEngineReader.getResourceId()));
-      for (int i = 0, previousRefKeysSize = reference.getPageFragments().size(); i < previousRefKeysSize
-          && previousPageFragmentKeys.size() < revToRestore - 1; i++) {
+      previousPageFragmentKeys.add(new PageFragmentKeyImpl(
+          firstPage.getRevision(), 
+          reference.getKey(),
+          (int) storageEngineReader.getDatabaseId(),
+          (int) storageEngineReader.getResourceId()));
+      for (int i = 0, previousRefKeysSize = reference.getPageFragments().size();
+           i < previousRefKeysSize && previousPageFragmentKeys.size() < revToRestore - 1; i++) {
         previousPageFragmentKeys.add(reference.getPageFragments().get(i));
       }
 
@@ -343,15 +425,12 @@ public > PageContainer combineRe
       final T modifiedPage = firstPage.newInstance(recordPageKey, firstPage.getIndexType(), storageEngineReader);
       final boolean isFullDump = pages.size() == revToRestore;
 
-      // DIAGNOSTIC
-      if (KeyValueLeafPage.DEBUG_MEMORY_LEAKS && recordPageKey == 0) {
-        LOGGER.debug("INCREMENTAL combineForMod created: complete=" + System.identityHashCode(completePage)
-            + ", modified=" + System.identityHashCode(modifiedPage));
-      }
+      final long[] inWindowBitmap = new long[PageLayout.BITMAP_WORDS];
 
-      // Use bitmap for O(k) iteration instead of O(1024)
       final KeyValueLeafPage completeKvp = (KeyValueLeafPage) completePage;
       final KeyValueLeafPage modifiedKvp = (KeyValueLeafPage) modifiedPage;
+      completeKvp.ensureSlottedPage();
+      modifiedKvp.ensureSlottedPage();
       final long[] filledBitmap = completeKvp.getSlotBitmap();
 
       // Track slot count incrementally - CRITICAL: don't call populatedSlotCount() in loop
@@ -365,10 +444,35 @@ public > PageContainer combineRe
 
         // Use bitmap iteration for O(k) instead of O(1024)
         final KeyValueLeafPage kvPage = (KeyValueLeafPage) page;
-        filledSlotCount = copyMissingSlotsFromBitmapUntilFull(page, completePage, kvPage.getSlotBitmap(), filledBitmap,
-            filledSlotCount, isFullDump
-                ? modifiedKvp
-                : null);
+        final int[] populatedSlots = kvPage.populatedSlots();
+
+        for (final int offset : populatedSlots) {
+          // Check if slot already filled using bitmap (O(1))
+          if ((filledBitmap[offset >>> 6] & (1L << (offset & 63))) != 0) {
+            continue;  // Already filled from newer fragment
+          }
+
+          final var recordData = page.getSlot(offset);
+          completeKvp.setSlotWithNodeKind(recordData, offset, kvPage.getSlotNodeKindId(offset));
+          filledBitmap[offset >>> 6] |= (1L << (offset & 63));
+          filledSlotCount++;
+
+          if (isFullDump) {
+            // LAZY COPY: Mark slot for preservation instead of copying
+            // Actual copy from completePage happens in addReferences() if records[offset] == null
+            modifiedKvp.markSlotForPreservation(offset);
+          }
+
+          final var deweyId = page.getDeweyId(offset);
+          if (deweyId != null) {
+            completePage.setDeweyId(deweyId, offset);
+            // DeweyId will be lazily copied along with slot in addReferences()
+          }
+
+          if (filledSlotCount == Constants.NDP_NODE_COUNT) {
+            break;
+          }
+        }
 
         if (filledSlotCount < Constants.NDP_NODE_COUNT) {
           for (final Entry entry : page.referenceEntrySet()) {
@@ -395,7 +499,7 @@ public > PageContainer combineRe
       }
 
       final var pageContainer = PageContainer.getInstance(completePage, modifiedPage);
-      log.put(reference, pageContainer); // TIL will remove from caches before mutating
+      log.put(reference, pageContainer);  // TIL will remove from caches before mutating
       return pageContainer;
     }
 
@@ -435,11 +539,12 @@ public > T combineRecordPages(fi
       // Track which slots are already filled using bitmap from returnVal
       // This enables O(k) iteration instead of O(1024)
       final KeyValueLeafPage returnKvp = (KeyValueLeafPage) returnVal;
+      returnKvp.ensureSlottedPage();
       final long[] filledBitmap = returnKvp.getSlotBitmap();
-
+      
       // Track slot count incrementally - CRITICAL: don't call populatedSlotCount() in loop
       int filledSlotCount = 0;
-
+      
       for (final T page : pages) {
         assert page.getPageKey() == recordPageKey;
         if (filledSlotCount == Constants.NDP_NODE_COUNT) {
@@ -448,8 +553,30 @@ public > T combineRecordPages(fi
 
         // Use bitmap iteration for O(k) instead of O(1024)
         final KeyValueLeafPage kvPage = (KeyValueLeafPage) page;
-        filledSlotCount = copyMissingSlotsFromBitmapUntilFull(page, returnVal, kvPage.getSlotBitmap(), filledBitmap,
-            filledSlotCount, null);
+        final int[] populatedSlots = kvPage.populatedSlots();
+
+        for (final int offset : populatedSlots) {
+          // Check if slot already filled using bitmap (O(1))
+          if ((filledBitmap[offset >>> 6] & (1L << (offset & 63))) != 0) {
+            continue;  // Already filled from newer fragment
+          }
+
+          final var recordData = page.getSlot(offset);
+          returnKvp.setSlotWithNodeKind(recordData, offset, kvPage.getSlotNodeKindId(offset));
+          // Keep local bitmap in sync with slotted page bitmap so that older fragments
+          // don't overwrite newer data (setSlotToHeap only updates the slotted page bitmap)
+          filledBitmap[offset >>> 6] |= (1L << (offset & 63));
+          filledSlotCount++;
+
+          final var deweyId = page.getDeweyId(offset);
+          if (deweyId != null) {
+            returnVal.setDeweyId(deweyId, offset);
+          }
+
+          if (filledSlotCount == Constants.NDP_NODE_COUNT) {
+            break;
+          }
+        }
 
         if (filledSlotCount < Constants.NDP_NODE_COUNT) {
           for (final Entry entry : page.referenceEntrySet()) {
@@ -472,15 +599,18 @@ public > T combineRecordPages(fi
 
     @Override
     public > PageContainer combineRecordPagesForModification(
-        final List pages, final int revToRestore, final StorageEngineReader storageEngineReader,
-        final PageReference reference, final TransactionIntentLog log) {
+        final List pages, final int revToRestore, final StorageEngineReader storageEngineReader, final PageReference reference,
+        final TransactionIntentLog log) {
       final T firstPage = pages.getFirst();
       final long recordPageKey = firstPage.getPageKey();
       final var previousPageFragmentKeys = new ArrayList(reference.getPageFragments().size() + 1);
-      previousPageFragmentKeys.add(new PageFragmentKeyImpl(firstPage.getRevision(), reference.getKey(),
-          (int) storageEngineReader.getDatabaseId(), (int) storageEngineReader.getResourceId()));
-      for (int i = 0, previousRefKeysSize = reference.getPageFragments().size(); i < previousRefKeysSize
-          && previousPageFragmentKeys.size() < revToRestore - 1; i++) {
+      previousPageFragmentKeys.add(new PageFragmentKeyImpl(
+          firstPage.getRevision(), 
+          reference.getKey(),
+          (int) storageEngineReader.getDatabaseId(),
+          (int) storageEngineReader.getResourceId()));
+      for (int i = 0, previousRefKeysSize = reference.getPageFragments().size();
+           i < previousRefKeysSize && previousPageFragmentKeys.size() < revToRestore - 1; i++) {
         previousPageFragmentKeys.add(reference.getPageFragments().get(i));
       }
 
@@ -491,29 +621,23 @@ public > PageContainer combineRe
       // This saves 64KB allocation per combine operation
       final T completePage = firstPage.newInstance(recordPageKey, firstPage.getIndexType(), storageEngineReader);
       final T modifyingPage = firstPage.newInstance(recordPageKey, firstPage.getIndexType(), storageEngineReader);
-
+      
       // OPTIMIZATION: Use bitmap (128 bytes) instead of temp page (64KB)
       // inWindowBitmap tracks which slots exist in the sliding window
-      final long[] inWindowBitmap = new long[SLOT_BITMAP_WORD_COUNT];
-
-      // DIAGNOSTIC
-      if (KeyValueLeafPage.DEBUG_MEMORY_LEAKS && recordPageKey == 0) {
-        LOGGER.debug("SLIDING_SNAPSHOT combineForMod created 2 pages + bitmap: complete="
-            + System.identityHashCode(completePage) + ", modifying=" + System.identityHashCode(modifyingPage));
-      }
-
+      final long[] inWindowBitmap = new long[16];  // 16 * 64 = 1024 bits
+      
       final KeyValueLeafPage completeKvp = (KeyValueLeafPage) completePage;
       final KeyValueLeafPage modifyingKvp = (KeyValueLeafPage) modifyingPage;
+      completeKvp.ensureSlottedPage();
+      modifyingKvp.ensureSlottedPage();
       final long[] filledBitmap = completeKvp.getSlotBitmap();
-
+      
       final boolean hasOutOfWindowPage = (pages.size() == revToRestore);
-      final int lastInWindowIndex = hasOutOfWindowPage
-          ? pages.size() - 2
-          : pages.size() - 1;
-
+      final int lastInWindowIndex = hasOutOfWindowPage ? pages.size() - 2 : pages.size() - 1;
+      
       // Track slot count incrementally - CRITICAL: don't call populatedSlotCount() in loop
       int filledSlotCount = 0;
-
+      
       // Phase 1: Process in-window fragments, track populated slots in bitmap
       for (int i = 0; i <= lastInWindowIndex; i++) {
         final T page = pages.get(i);
@@ -521,8 +645,31 @@ public > PageContainer combineRe
 
         // Use bitmap iteration for O(k) instead of O(1024)
         final KeyValueLeafPage kvPage = (KeyValueLeafPage) page;
-        filledSlotCount = copyMissingSlotsFromBitmapUntilFullTrackingWindow(page, completePage, kvPage.getSlotBitmap(),
-            filledBitmap, inWindowBitmap, filledSlotCount);
+        final int[] populatedSlots = kvPage.populatedSlots();
+
+        for (final int offset : populatedSlots) {
+          // Mark slot as in-window (for Phase 2 check)
+          inWindowBitmap[offset >>> 6] |= (1L << (offset & 63));
+          
+          // Check if slot already filled in completePage using bitmap (O(1))
+          if ((filledBitmap[offset >>> 6] & (1L << (offset & 63))) != 0) {
+            continue;  // Already filled from newer fragment
+          }
+
+          final var recordData = page.getSlot(offset);
+          completeKvp.setSlotWithNodeKind(recordData, offset, kvPage.getSlotNodeKindId(offset));
+          filledBitmap[offset >>> 6] |= (1L << (offset & 63));
+          filledSlotCount++;
+
+          final var deweyId = page.getDeweyId(offset);
+          if (deweyId != null) {
+            completePage.setDeweyId(deweyId, offset);
+          }
+
+          if (filledSlotCount == Constants.NDP_NODE_COUNT) {
+            break;  // Page is full
+          }
+        }
 
         // Handle references
         for (final Entry entry : page.referenceEntrySet()) {
@@ -533,7 +680,7 @@ public > PageContainer combineRe
         }
 
         if (filledSlotCount == Constants.NDP_NODE_COUNT) {
-          break; // Page is full
+          break;  // Page is full
         }
       }
 
@@ -545,9 +692,29 @@ public > PageContainer combineRe
         assert outOfWindowPage.getPageKey() == recordPageKey;
 
         final KeyValueLeafPage outOfWindowKvp = (KeyValueLeafPage) outOfWindowPage;
-        copyOutOfWindowSlotsAndMarkPreservation(outOfWindowPage, completePage, outOfWindowKvp.getSlotBitmap(),
-            filledBitmap, inWindowBitmap, modifyingKvp);
-
+        final int[] populatedSlots = outOfWindowKvp.populatedSlots();
+
+        for (final int offset : populatedSlots) {
+          final var recordData = outOfWindowPage.getSlot(offset);
+          final var deweyId = outOfWindowPage.getDeweyId(offset);
+
+          // Add to completePage if not already filled
+          if ((filledBitmap[offset >>> 6] & (1L << (offset & 63))) == 0) {
+            completeKvp.setSlotWithNodeKind(recordData, offset, outOfWindowKvp.getSlotNodeKindId(offset));
+            filledBitmap[offset >>> 6] |= (1L << (offset & 63));
+            if (deweyId != null) {
+              completePage.setDeweyId(deweyId, offset);
+            }
+          }
+          
+          // If slot is NOT in the sliding window, mark for preservation in modifyingPage
+          // (these are records falling out of the window that need to be written)
+          if ((inWindowBitmap[offset >>> 6] & (1L << (offset & 63))) == 0) {
+            // LAZY COPY: Mark slot for preservation instead of copying
+            modifyingKvp.markSlotForPreservation(offset);
+          }
+        }
+        
         // Handle references from out-of-window page
         for (final Entry entry : outOfWindowPage.referenceEntrySet()) {
           final Long key = entry.getKey();
@@ -560,7 +727,7 @@ public > PageContainer combineRe
             modifyingPage.setPageReference(key, entry.getValue());
           }
         }
-
+        
         // Set completePage reference for lazy copying at commit time
         modifyingKvp.setCompletePageRef(completeKvp);
       }
@@ -570,7 +737,7 @@ public > PageContainer combineRe
       propagateFsstSymbolTable(firstPage, modifyingPage);
 
       final var pageContainer = PageContainer.getInstance(completePage, modifyingPage);
-      log.put(reference, pageContainer); // TIL will remove from caches before mutating
+      log.put(reference, pageContainer);  // TIL will remove from caches before mutating
       return pageContainer;
     }
 
@@ -596,7 +763,6 @@ private int[] convertIntegers(final List integers) {
   };
 
   private static final Logger LOGGER = LoggerFactory.getLogger(VersioningType.class);
-  private static final int SLOT_BITMAP_WORD_COUNT = (Constants.NDP_NODE_COUNT + Long.SIZE - 1) >>> 6;
 
   public static VersioningType fromString(String versioningType) {
     for (final var type : values()) {
@@ -608,10 +774,10 @@ public static VersioningType fromString(String versioningType) {
   }
 
   /**
-   * Method to reconstruct a complete {@link KeyValuePage} with the help of partly filled pages plus a
-   * revision-delta which determines the necessary steps back.
+   * Method to reconstruct a complete {@link KeyValuePage} with the help of partly filled pages plus
+   * a revision-delta which determines the necessary steps back.
    *
-   * @param pages the base of the complete {@link KeyValuePage}
+   * @param pages         the base of the complete {@link KeyValuePage}
    * @param revsToRestore the number of revisions needed to build the complete record page
    * @return the complete {@link KeyValuePage}
    */
@@ -622,10 +788,10 @@ public abstract > T combineRecor
    * Method to reconstruct a complete {@link KeyValuePage} for reading as well as a
    * {@link KeyValuePage} for serializing with the nodes to write.
    *
-   * @param pages the base of the complete {@link KeyValuePage}
+   * @param pages         the base of the complete {@link KeyValuePage}
    * @param revsToRestore the revisions needed to build the complete record page
    * @return a {@link PageContainer} holding a complete {@link KeyValuePage} for reading and one for
-   *         writing
+   * writing
    */
   public abstract > PageContainer combineRecordPagesForModification(
       final List pages, final @NonNegative int revsToRestore, final StorageEngineReader storageEngineReader,
@@ -635,192 +801,70 @@ public abstract > PageContainer
    * Get all revision root page numbers which are needed to restore a {@link KeyValuePage}.
    *
    * @param previousRevision the previous revision
-   * @param revsToRestore number of revisions to restore
+   * @param revsToRestore    number of revisions to restore
    * @return revision root page numbers needed to restore a {@link KeyValuePage}
    */
   public abstract int[] getRevisionRoots(final @NonNegative int previousRevision, final @NonNegative int revsToRestore);
 
   /**
-   * Propagate FSST symbol table from source page to target page. This is needed when combining page
-   * fragments to ensure the combined page can decompress string values.
+   * Propagate FSST symbol table from source page to target page.
+   * This is needed when combining page fragments to ensure the combined page
+   * can decompress string values.
    *
    * @param sourcePage the source page with the FSST symbol table
    * @param targetPage the target page to set the symbol table on
    * @param  the data record type
    * @param  the key-value page type
    */
-  protected static > void propagateFsstSymbolTable(final T sourcePage,
-      final T targetPage) {
-    if (sourcePage instanceof KeyValueLeafPage sourceKvp && targetPage instanceof KeyValueLeafPage targetKvp) {
-      final byte[] fsstSymbolTable = sourceKvp.getFsstSymbolTable();
+  protected static > void propagateFsstSymbolTable(
+      final T sourcePage, final T targetPage) {
+    if (sourcePage instanceof KeyValueLeafPage sourceKvp 
+        && targetPage instanceof KeyValueLeafPage targetKvp) {
+      byte[] fsstSymbolTable = sourceKvp.getFsstSymbolTable();
       if (fsstSymbolTable != null && fsstSymbolTable.length > 0) {
         targetKvp.setFsstSymbolTable(fsstSymbolTable);
       }
     }
   }
 
-  private static > void copySlotAndDeweyId(final T sourcePage,
-      final T targetPage, final int offset, final MemorySegment slot) {
-    if (slot == null) {
-      return;
-    }
-    targetPage.setSlot(slot, offset);
-    final var deweyId = sourcePage.getDeweyId(offset);
-    if (deweyId != null) {
-      targetPage.setDeweyId(deweyId, offset);
-    }
-  }
-
-  private static > void copyAllSlotsFromBitmap(final T sourcePage,
-      final T targetPage, final long[] sourceBitmap, final KeyValueLeafPage preserveTargetPage) {
-    for (int wordIndex = 0; wordIndex < sourceBitmap.length; wordIndex++) {
-      long word = sourceBitmap[wordIndex];
-      final int baseOffset = wordIndex << 6;
-      while (word != 0) {
-        final int offset = baseOffset + Long.numberOfTrailingZeros(word);
-        copySlotAndDeweyId(sourcePage, targetPage, offset, sourcePage.getSlot(offset));
-        if (preserveTargetPage != null) {
-          preserveTargetPage.markSlotForPreservation(offset);
-        }
-        word &= word - 1;
-      }
-    }
-  }
-
-  private static > void copyMissingSlotsFromBitmap(final T sourcePage,
-      final T targetPage, final long[] sourceBitmap, final long[] targetBitmap,
-      final KeyValueLeafPage preserveTargetPage) {
-    for (int wordIndex = 0; wordIndex < sourceBitmap.length; wordIndex++) {
-      long word = sourceBitmap[wordIndex];
-      final int baseOffset = wordIndex << 6;
-      while (word != 0) {
-        final int offset = baseOffset + Long.numberOfTrailingZeros(word);
-        if (!isBitSet(targetBitmap, offset)) {
-          copySlotAndDeweyId(sourcePage, targetPage, offset, sourcePage.getSlot(offset));
-          if (preserveTargetPage != null) {
-            preserveTargetPage.markSlotForPreservation(offset);
-          }
-        }
-        word &= word - 1;
-      }
-    }
-  }
-
-  private static > int copyMissingSlotsFromBitmapUntilFull(
-      final T sourcePage, final T targetPage, final long[] sourceBitmap, final long[] targetBitmap, int filledSlotCount,
-      final KeyValueLeafPage preserveTargetPage) {
-    for (int wordIndex = 0; wordIndex < sourceBitmap.length; wordIndex++) {
-      long word = sourceBitmap[wordIndex];
-      final int baseOffset = wordIndex << 6;
-      while (word != 0) {
-        final int offset = baseOffset + Long.numberOfTrailingZeros(word);
-        if (!isBitSet(targetBitmap, offset)) {
-          copySlotAndDeweyId(sourcePage, targetPage, offset, sourcePage.getSlot(offset));
-          if (preserveTargetPage != null) {
-            preserveTargetPage.markSlotForPreservation(offset);
-          }
-          filledSlotCount++;
-          if (filledSlotCount == Constants.NDP_NODE_COUNT) {
-            return filledSlotCount;
-          }
-        }
-        word &= word - 1;
-      }
-    }
-    return filledSlotCount;
-  }
-
-  private static > int copyMissingSlotsFromBitmapUntilFullTrackingWindow(
-      final T sourcePage, final T targetPage, final long[] sourceBitmap, final long[] targetBitmap,
-      final long[] inWindowBitmap, int filledSlotCount) {
-    for (int wordIndex = 0; wordIndex < sourceBitmap.length; wordIndex++) {
-      long word = sourceBitmap[wordIndex];
-      final int baseOffset = wordIndex << 6;
-      while (word != 0) {
-        final int offset = baseOffset + Long.numberOfTrailingZeros(word);
-        setBit(inWindowBitmap, offset);
-        if (!isBitSet(targetBitmap, offset)) {
-          copySlotAndDeweyId(sourcePage, targetPage, offset, sourcePage.getSlot(offset));
-          filledSlotCount++;
-          if (filledSlotCount == Constants.NDP_NODE_COUNT) {
-            return filledSlotCount;
-          }
-        }
-        word &= word - 1;
-      }
-    }
-    return filledSlotCount;
-  }
-
-  private static > void copyOutOfWindowSlotsAndMarkPreservation(
-      final T outOfWindowPage, final T completePage, final long[] outOfWindowBitmap, final long[] completePageBitmap,
-      final long[] inWindowBitmap, final KeyValueLeafPage modifyingPage) {
-    for (int wordIndex = 0; wordIndex < outOfWindowBitmap.length; wordIndex++) {
-      long word = outOfWindowBitmap[wordIndex];
-      final int baseOffset = wordIndex << 6;
-      while (word != 0) {
-        final int offset = baseOffset + Long.numberOfTrailingZeros(word);
-
-        // Add to completePage if not already filled.
-        if (!isBitSet(completePageBitmap, offset)) {
-          copySlotAndDeweyId(outOfWindowPage, completePage, offset, outOfWindowPage.getSlot(offset));
-        }
-
-        // If slot is NOT in the sliding window, mark for preservation in modifyingPage.
-        if (!isBitSet(inWindowBitmap, offset)) {
-          modifyingPage.markSlotForPreservation(offset);
-        }
-        word &= word - 1;
-      }
-    }
-  }
-
-  private static void setBit(final long[] bitmap, final int offset) {
-    bitmap[offset >>> 6] |= (1L << (offset & 63));
-  }
-
-  private static boolean isBitSet(final long[] bitmap, final int offset) {
-    return (bitmap[offset >>> 6] & (1L << (offset & 63))) != 0;
-  }
-
   // ===== HOT Leaf Page Combining Methods =====
 
   /**
    * Combine multiple HOT leaf page fragments into a single complete page.
    *
-   * 

-   * Unlike slot-based combining for KeyValueLeafPage, HOT pages use key-based merging with
-   * NodeReferences OR semantics. Newer fragments take precedence, and tombstones (empty
-   * NodeReferences) indicate deletions.
-   * 

+   * 
Unlike slot-based combining for KeyValueLeafPage, HOT pages use key-based
+   * merging with NodeReferences OR semantics. Newer fragments take precedence,
+   * and tombstones (empty NodeReferences) indicate deletions.

    *
    * @param pages the list of HOT leaf page fragments (newest first)
    * @param revToRestore the revision to restore
    * @param storageEngineReader the storage engine reader
    * @return the combined HOT leaf page
    */
-  public HOTLeafPage combineHOTLeafPages(final List pages, final @NonNegative int revToRestore,
+  public HOTLeafPage combineHOTLeafPages(
+      final List pages,
+      final @NonNegative int revToRestore,
       final StorageEngineReader storageEngineReader) {
-
+    
     if (pages.isEmpty()) {
       throw new IllegalArgumentException("No pages to combine");
     }
-
+    
     if (pages.size() == 1) {
       return pages.getFirst();
     }
-
+    
     // Start with a copy of the newest page
     HOTLeafPage result = pages.getFirst().copy();
-
+    
     // Merge older fragments (skip first as it's already the base)
     for (int i = 1; i < pages.size(); i++) {
       HOTLeafPage olderPage = pages.get(i);
-
+      
       // Merge each entry from older page
       for (int j = 0; j < olderPage.getEntryCount(); j++) {
         byte[] key = olderPage.getKey(j);
-
+        
         // Check if key exists in result
         int existingIdx = result.findEntry(key);
         if (existingIdx < 0) {
@@ -835,17 +879,15 @@ public HOTLeafPage combineHOTLeafPages(final List pages, final @Non
         // If key exists in newer fragment, it takes precedence (already in result)
       }
     }
-
+    
     return result;
   }
 
   /**
    * Combine HOT leaf page fragments for modification (COW).
    *
-   * 

-   * Creates a copy of the combined page for modification while preserving the original for readers
-   * (Copy-on-Write isolation).
-   * 

+   * 
Creates a copy of the combined page for modification while preserving
+   * the original for readers (Copy-on-Write isolation).

    *
    * @param pages the list of HOT leaf page fragments (newest first)
    * @param revToRestore the revision to restore
@@ -854,20 +896,23 @@ public HOTLeafPage combineHOTLeafPages(final List pages, final @Non
    * @param log the transaction intent log
    * @return the page container with complete and modified pages
    */
-  public PageContainer combineHOTLeafPagesForModification(final List pages,
-      final @NonNegative int revToRestore, final StorageEngineReader storageEngineReader, final PageReference reference,
+  public PageContainer combineHOTLeafPagesForModification(
+      final List pages,
+      final @NonNegative int revToRestore,
+      final StorageEngineReader storageEngineReader,
+      final PageReference reference,
       final TransactionIntentLog log) {
-
+    
     // Combine fragments
     HOTLeafPage completePage = combineHOTLeafPages(pages, revToRestore, storageEngineReader);
-
+    
     // Create COW copy for modification
     HOTLeafPage modifiedPage = completePage.copy();
-
+    
     // Create container with both pages
     final var pageContainer = PageContainer.getInstance(completePage, modifiedPage);
     log.put(reference, pageContainer);
-
+    
     return pageContainer;
   }
 
@@ -876,23 +921,23 @@ public PageContainer combineHOTLeafPagesForModification(final List
   /**
    * Combine BitmapChunkPage fragments according to versioning strategy.
    *
-   * 

-   * Takes a list of bitmap chunk page fragments (newest first) and combines them into a complete
-   * bitmap representing the current state.
-   * 

+   * 
Takes a list of bitmap chunk page fragments (newest first) and combines them
+   * into a complete bitmap representing the current state.

    *
    * @param fragments the list of bitmap chunk page fragments (newest first)
    * @param revToRestore the revision to restore
    * @param storageEngineReader the storage engine reader
    * @return the combined bitmap chunk page with complete data
    */
-  public BitmapChunkPage combineBitmapChunks(final List fragments, final @NonNegative int revToRestore,
+  public BitmapChunkPage combineBitmapChunks(
+      final List fragments,
+      final @NonNegative int revToRestore,
       final StorageEngineReader storageEngineReader) {
-
+    
     if (fragments.isEmpty()) {
       throw new IllegalArgumentException("No fragments to combine");
     }
-
+    
     if (fragments.size() == 1) {
       BitmapChunkPage singlePage = fragments.getFirst();
       if (singlePage.isDeleted()) {
@@ -902,41 +947,38 @@ public BitmapChunkPage combineBitmapChunks(final List fragments
         return singlePage; // Full snapshot - already complete
       }
       // Delta page without base - shouldn't happen in valid state
-      LOGGER.warn("Single delta page without base for chunk range [{}, {})", singlePage.getRangeStart(),
-          singlePage.getRangeEnd());
+      LOGGER.warn("Single delta page without base for chunk range [{}, {})",
+          singlePage.getRangeStart(), singlePage.getRangeEnd());
       return singlePage.copyAsFull(singlePage.getRevision());
     }
-
+    
     // Find the base snapshot (should be the last/oldest page)
     BitmapChunkPage basePage = fragments.getLast();
     if (!basePage.isFullSnapshot() && !basePage.isDeleted()) {
-      LOGGER.warn("Base page is not a full snapshot for chunk range [{}, {})", basePage.getRangeStart(),
-          basePage.getRangeEnd());
+      LOGGER.warn("Base page is not a full snapshot for chunk range [{}, {})",
+          basePage.getRangeStart(), basePage.getRangeEnd());
     }
-
+    
     // Start with base bitmap
-    org.roaringbitmap.longlong.Roaring64Bitmap combined = basePage.getBitmap() != null
-        ? basePage.getBitmap().clone()
-        : new org.roaringbitmap.longlong.Roaring64Bitmap();
-
+    org.roaringbitmap.longlong.Roaring64Bitmap combined = 
+        basePage.getBitmap() != null ? basePage.getBitmap().clone() : new org.roaringbitmap.longlong.Roaring64Bitmap();
+    
     // Apply deltas from oldest to newest (skip base)
     for (int i = fragments.size() - 2; i >= 0; i--) {
       BitmapChunkPage deltaPage = fragments.get(i);
-
+      
       if (deltaPage.isDeleted()) {
         // Tombstone - clear everything
         combined = new org.roaringbitmap.longlong.Roaring64Bitmap();
         continue;
       }
-
+      
       if (deltaPage.isFullSnapshot()) {
         // Full snapshot replaces everything
-        combined = deltaPage.getBitmap() != null
-            ? deltaPage.getBitmap().clone()
-            : new org.roaringbitmap.longlong.Roaring64Bitmap();
+        combined = deltaPage.getBitmap() != null ? deltaPage.getBitmap().clone() : new org.roaringbitmap.longlong.Roaring64Bitmap();
         continue;
       }
-
+      
       if (deltaPage.isDelta()) {
         // Apply additions
         if (deltaPage.getAdditions() != null && !deltaPage.getAdditions().isEmpty()) {
@@ -948,20 +990,25 @@ public BitmapChunkPage combineBitmapChunks(final List fragments
         }
       }
     }
-
+    
     // Create result as full snapshot
     BitmapChunkPage newestPage = fragments.getFirst();
-    return BitmapChunkPage.createFull(newestPage.getPageKey(), newestPage.getRevision(), newestPage.getIndexType(),
-        newestPage.getRangeStart(), newestPage.getRangeEnd(), combined);
+    return BitmapChunkPage.createFull(
+        newestPage.getPageKey(),
+        newestPage.getRevision(),
+        newestPage.getIndexType(),
+        newestPage.getRangeStart(),
+        newestPage.getRangeEnd(),
+        combined
+    );
   }
 
   /**
    * Prepare a BitmapChunkPage for modification.
    *
-   * 

-   * Loads existing fragments, combines them, and creates a new page for the current transaction. The
-   * versioning strategy determines whether to create a full snapshot or a delta page.
-   * 

+   * 
Loads existing fragments, combines them, and creates a new page for
+   * the current transaction. The versioning strategy determines whether
+   * to create a full snapshot or a delta page.

    *
    * @param fragments existing page fragments (newest first), may be empty for new chunks
    * @param currentRevision the current transaction revision
@@ -974,30 +1021,34 @@ public BitmapChunkPage combineBitmapChunks(final List fragments
    * @param storageEngineReader the storage engine reader
    * @return the page container with complete and modified pages
    */
-  public PageContainer prepareBitmapChunkForModification(final List fragments,
-      final int currentRevision, final @NonNegative int revsToRestore, final long rangeStart, final long rangeEnd,
-      final io.sirix.index.IndexType indexType, final PageReference reference, final TransactionIntentLog log,
+  public PageContainer prepareBitmapChunkForModification(
+      final List fragments,
+      final int currentRevision,
+      final @NonNegative int revsToRestore,
+      final long rangeStart,
+      final long rangeEnd,
+      final io.sirix.index.IndexType indexType,
+      final PageReference reference,
+      final TransactionIntentLog log,
       final StorageEngineReader storageEngineReader) {
-
+    
     // Determine if we should create a full snapshot
     final boolean isFullDump = shouldStoreBitmapFullSnapshot(fragments, currentRevision, revsToRestore);
-
-    final long pageKey = reference.getKey() >= 0
-        ? reference.getKey()
-        : allocateNewPageKey(storageEngineReader);
-
+    
+    final long pageKey = reference.getKey() >= 0 ? reference.getKey() : allocateNewPageKey(storageEngineReader);
+    
     if (fragments.isEmpty()) {
       // New chunk - create empty full snapshot
-      BitmapChunkPage newPage =
-          BitmapChunkPage.createEmptyFull(pageKey, currentRevision, indexType, rangeStart, rangeEnd);
+      BitmapChunkPage newPage = BitmapChunkPage.createEmptyFull(
+          pageKey, currentRevision, indexType, rangeStart, rangeEnd);
       PageContainer container = PageContainer.getInstance(newPage, newPage);
       log.put(reference, container);
       return container;
     }
-
+    
     // Combine existing fragments
     BitmapChunkPage completePage = combineBitmapChunks(fragments, revsToRestore, storageEngineReader);
-
+    
     // Create modified page based on versioning strategy
     BitmapChunkPage modifiedPage;
     if (isFullDump) {
@@ -1005,9 +1056,10 @@ public PageContainer prepareBitmapChunkForModification(final List
-   * Strategy-specific logic:
-   * 

+   * 
Strategy-specific logic:

    * 
    
-   * 
  • FULL: Always returns true
    • 
-   * 
  • INCREMENTAL: Returns true when chain length >= revsToRestore - 1
    • 
-   * 
  • DIFFERENTIAL: Returns true when currentRevision % revsToRestore == 0
    • 
-   * 
  • SLIDING_SNAPSHOT: Same as INCREMENTAL with window-based GC
    • 
+   *   
  • FULL: Always returns true
    • 
+   *   
  • INCREMENTAL: Returns true when chain length >= revsToRestore - 1
    • 
+   *   
  • DIFFERENTIAL: Returns true when currentRevision % revsToRestore == 0
    • 
+   *   
  • SLIDING_SNAPSHOT: Same as INCREMENTAL with window-based GC
    • 
    * 

    *
    * @param fragments existing fragments (for chain length check)
@@ -1031,14 +1081,16 @@ public PageContainer prepareBitmapChunkForModification(final List fragments, final int currentRevision,
+  public boolean shouldStoreBitmapFullSnapshot(
+      final List fragments,
+      final int currentRevision,
       final @NonNegative int revsToRestore) {
-
+    
     // First revision is always full
     if (currentRevision == 1 || fragments.isEmpty()) {
       return true;
     }
-
+    
     return switch (this) {
       case FULL -> true;
       case DIFFERENTIAL -> currentRevision % revsToRestore == 0;
@@ -1047,16 +1099,12 @@ public boolean shouldStoreBitmapFullSnapshot(final List fragmen
   }
 
   /**
-   * Allocate a fallback page key for bitmap chunk pages when no reference key exists yet.
-   *
-   * 

-   * Using a monotonic nanoTime source preserves lock-free behavior on this path and keeps allocations
-   * at zero. This method remains a placeholder until bitmap chunks are wired into the regular
-   * revision-root page-key allocator.
-   * 

+   * Allocate a new page key.
+   * This is a placeholder - actual implementation uses RevisionRootPage.
    */
-  private long allocateNewPageKey(final StorageEngineReader storageEngineReader) {
-    return System.nanoTime();
+  private long allocateNewPageKey(StorageEngineReader storageEngineReader) {
+    // TODO: Integrate with RevisionRootPage page key allocation
+    return System.nanoTime(); // Temporary unique key
   }
 }
 
diff --git a/bundles/sirix-core/src/test/java/io/sirix/access/node/xml/XmlNodeReadOnlyTrxImplTest.java b/bundles/sirix-core/src/test/java/io/sirix/access/node/xml/XmlNodeReadOnlyTrxImplTest.java
index eac140ac5..eaa8561bc 100644
--- a/bundles/sirix-core/src/test/java/io/sirix/access/node/xml/XmlNodeReadOnlyTrxImplTest.java
+++ b/bundles/sirix-core/src/test/java/io/sirix/access/node/xml/XmlNodeReadOnlyTrxImplTest.java
@@ -120,7 +120,7 @@ public void testConventions() {
   }
 
   @Test
-  public void testMoveToReusesXmlElementSingleton() {
+  public void testMoveToReadsCorrectXmlElements() {
     final InternalXmlNodeReadOnlyTrx rtx = (InternalXmlNodeReadOnlyTrx) holder.getXmlNodeReadTrx();
     assertTrue(rtx.moveToDocumentRoot());
 
@@ -143,13 +143,16 @@ public void testMoveToReusesXmlElementSingleton() {
     assertTrue(secondElementKey != Fixed.NULL_NODE_KEY.getStandardProperty());
 
     assertTrue(rtx.moveTo(firstElementKey));
-    final StructNode firstSingleton = rtx.getStructuralNode();
-    assertEquals(firstElementKey, firstSingleton.getNodeKey());
+    final StructNode firstNode = rtx.getStructuralNode();
+    assertEquals(firstElementKey, firstNode.getNodeKey());
 
     assertTrue(rtx.moveTo(secondElementKey));
-    final StructNode secondSingleton = rtx.getStructuralNode();
-    assertSame(firstSingleton, secondSingleton);
-    assertEquals(secondElementKey, secondSingleton.getNodeKey());
+    final StructNode secondNode = rtx.getStructuralNode();
+    assertEquals(secondElementKey, secondNode.getNodeKey());
+
+    // Verify moving back reads correct data
+    assertTrue(rtx.moveTo(firstElementKey));
+    assertEquals(firstElementKey, rtx.getStructuralNode().getNodeKey());
   }
 
 }
diff --git a/bundles/sirix-core/src/test/java/io/sirix/access/node/xml/XmlResourceSessionTest.java b/bundles/sirix-core/src/test/java/io/sirix/access/node/xml/XmlResourceSessionTest.java
index 64a21642c..d2537fe98 100644
--- a/bundles/sirix-core/src/test/java/io/sirix/access/node/xml/XmlResourceSessionTest.java
+++ b/bundles/sirix-core/src/test/java/io/sirix/access/node/xml/XmlResourceSessionTest.java
@@ -81,8 +81,8 @@ public void testClosed() {
     try {
       rtx.getAttributeCount();
       fail();
-    } catch (final AssertionError e) {
-      // assertNotClosed() uses a Java assert — throws AssertionError with -ea.
+    } catch (final IllegalStateException e) {
+      // assertNotClosed() throws IllegalStateException when transaction is closed.
     } finally {
       holder.getResourceSession().close();
     }
diff --git a/bundles/sirix-core/src/test/java/io/sirix/access/trx/node/json/JsonNodeFactoryImplTest.java b/bundles/sirix-core/src/test/java/io/sirix/access/trx/node/json/JsonNodeFactoryImplTest.java
index 68c91af2a..718967650 100644
--- a/bundles/sirix-core/src/test/java/io/sirix/access/trx/node/json/JsonNodeFactoryImplTest.java
+++ b/bundles/sirix-core/src/test/java/io/sirix/access/trx/node/json/JsonNodeFactoryImplTest.java
@@ -47,7 +47,9 @@
 import io.sirix.node.json.ObjectNumberNode;
 import io.sirix.node.json.ObjectStringNode;
 import io.sirix.node.json.StringNode;
+import io.sirix.page.KeyValueLeafPage;
 import io.sirix.page.RevisionRootPage;
+import io.sirix.settings.Constants;
 import io.sirix.settings.Fixed;
 import net.openhft.hashing.LongHashFunction;
 import org.junit.After;
@@ -95,13 +97,25 @@ public void setUp() {
     doReturn(resourceSession).when(storageEngineWriter).getResourceSession();
     when(storageEngineWriter.getRevisionNumber()).thenReturn(0);
 
-    // Mock createRecord to return the node passed to it
+    // Mock createRecord to return the node passed to it (used by PathNode, DeweyIDNode)
     when(storageEngineWriter.createRecord(any(DataRecord.class), any(IndexType.class), anyInt())).thenAnswer(
         invocation -> invocation.getArgument(0));
 
     // Mock createNameKey for ObjectKeyNode
     when(storageEngineWriter.createNameKey(anyString(), any(NodeKind.class))).thenReturn(5); // Return a dummy name key
 
+    // Mock allocation methods for direct-to-heap creation
+    final KeyValueLeafPage testKvl = new KeyValueLeafPage(0, IndexType.DOCUMENT, resourceConfig, 0, null, null);
+    final long[] allocatedKey = {0};
+    doAnswer(inv -> {
+      allocatedKey[0] = nodeCounter++;
+      return null;
+    }).when(storageEngineWriter).allocateForDocumentCreation();
+    when(storageEngineWriter.getAllocKvl()).thenReturn(testKvl);
+    when(storageEngineWriter.getAllocNodeKey()).thenAnswer(inv -> allocatedKey[0]);
+    when(storageEngineWriter.getAllocSlotOffset()).thenAnswer(
+        inv -> (int) (allocatedKey[0] % Constants.NDP_NODE_COUNT));
+
     factory = new JsonNodeFactoryImpl(LongHashFunction.xx3(), storageEngineWriter);
   }
 
@@ -133,8 +147,8 @@ public void testCreateJsonObjectNullNode_NoStructuralFields() {
     // CRITICAL: Object* value nodes should have NO children
     assertEquals(Fixed.NULL_NODE_KEY.getStandardProperty(), node.getFirstChildKey());
 
-    // Verify storageEngineWriter.createRecord was called
-    verify(storageEngineWriter).createRecord(eq(node), eq(IndexType.DOCUMENT), eq(-1));
+    // Verify allocateForDocumentCreation was called (direct-to-heap path)
+    verify(storageEngineWriter).allocateForDocumentCreation();
   }
 
   @Test
diff --git a/bundles/sirix-core/src/test/java/io/sirix/access/trx/node/xml/XmlNodeFactoryImplTest.java b/bundles/sirix-core/src/test/java/io/sirix/access/trx/node/xml/XmlNodeFactoryImplTest.java
index 132fe82f8..d7ed9b19d 100644
--- a/bundles/sirix-core/src/test/java/io/sirix/access/trx/node/xml/XmlNodeFactoryImplTest.java
+++ b/bundles/sirix-core/src/test/java/io/sirix/access/trx/node/xml/XmlNodeFactoryImplTest.java
@@ -1,7 +1,10 @@
 package io.sirix.access.trx.node.xml;
 
 import io.brackit.query.atomic.QNm;
+import io.sirix.XmlTestHelper;
+import io.sirix.access.ResourceConfiguration;
 import io.sirix.api.StorageEngineWriter;
+import io.sirix.api.xml.XmlResourceSession;
 import io.sirix.index.IndexType;
 import io.sirix.node.NodeKind;
 import io.sirix.node.interfaces.DataRecord;
@@ -11,9 +14,12 @@
 import io.sirix.node.xml.NamespaceNode;
 import io.sirix.node.xml.PINode;
 import io.sirix.node.xml.TextNode;
-import io.sirix.settings.Fixed;
+import io.sirix.page.KeyValueLeafPage;
 import io.sirix.page.RevisionRootPage;
+import io.sirix.settings.Constants;
+import io.sirix.settings.Fixed;
 import net.openhft.hashing.LongHashFunction;
+import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
 
@@ -28,6 +34,7 @@
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyInt;
 import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
@@ -35,10 +42,16 @@ public final class XmlNodeFactoryImplTest {
 
   private StorageEngineWriter storageEngineWriter;
   private XmlNodeFactoryImpl factory;
+  private XmlResourceSession resourceSession;
   private long nodeCounter;
 
   @Before
   public void setUp() {
+    XmlTestHelper.deleteEverything();
+    final var database = XmlTestHelper.getDatabase(XmlTestHelper.PATHS.PATH1.getFile());
+    resourceSession = database.beginResourceSession(XmlTestHelper.RESOURCE);
+    final ResourceConfiguration resourceConfig = resourceSession.getResourceConfig();
+
     storageEngineWriter = mock(StorageEngineWriter.class);
     final RevisionRootPage revisionRootPage = mock(RevisionRootPage.class);
     when(storageEngineWriter.getActualRevisionRootPage()).thenReturn(revisionRootPage);
@@ -48,9 +61,30 @@ public void setUp() {
         invocation -> invocation.getArgument(0));
     when(storageEngineWriter.createNameKey(anyString(), any(NodeKind.class))).thenAnswer(
         invocation -> Math.abs(invocation.getArgument(0, String.class).hashCode()));
+
+    // Mock allocation methods for direct-to-heap creation
+    final KeyValueLeafPage testKvl = new KeyValueLeafPage(0, IndexType.DOCUMENT, resourceConfig, 0, null, null);
+    final long[] allocatedKey = {0};
+    doAnswer(inv -> {
+      allocatedKey[0] = nodeCounter++;
+      return null;
+    }).when(storageEngineWriter).allocateForDocumentCreation();
+    when(storageEngineWriter.getAllocKvl()).thenReturn(testKvl);
+    when(storageEngineWriter.getAllocNodeKey()).thenAnswer(inv -> allocatedKey[0]);
+    when(storageEngineWriter.getAllocSlotOffset()).thenAnswer(
+        inv -> (int) (allocatedKey[0] % Constants.NDP_NODE_COUNT));
+
     factory = new XmlNodeFactoryImpl(LongHashFunction.xx3(), storageEngineWriter);
   }
 
+  @After
+  public void tearDown() {
+    if (resourceSession != null) {
+      resourceSession.close();
+    }
+    XmlTestHelper.closeEverything();
+  }
+
   @Test
   public void testFactoryReusesAttributeNodeProxy() {
     final AttributeNode first = factory.createAttributeNode(5L, new QNm("urn:first", "p1", "att1"),
diff --git a/bundles/sirix-core/src/test/java/io/sirix/access/trx/page/NodeStorageEngineReaderTest.java b/bundles/sirix-core/src/test/java/io/sirix/access/trx/page/NodeStorageEngineReaderTest.java
index 3498c3029..1d752d85b 100644
--- a/bundles/sirix-core/src/test/java/io/sirix/access/trx/page/NodeStorageEngineReaderTest.java
+++ b/bundles/sirix-core/src/test/java/io/sirix/access/trx/page/NodeStorageEngineReaderTest.java
@@ -6,8 +6,6 @@
 import io.sirix.cache.BufferManager;
 import io.sirix.cache.TransactionIntentLog;
 import io.sirix.index.IndexType;
-import io.sirix.node.NodeKind;
-import io.sirix.page.KeyValueLeafPage;
 import io.sirix.page.UberPage;
 
 import org.checkerframework.checker.nullness.qual.NonNull;
@@ -16,9 +14,6 @@
 import io.sirix.io.Reader;
 import io.sirix.settings.Constants;
 
-import java.lang.foreign.Arena;
-
-import static io.sirix.cache.LinuxMemorySegmentAllocator.SIXTYFOUR_KB;
 import static org.junit.Assert.assertEquals;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
@@ -43,31 +38,6 @@ public void testRecordPageOffset() {
     assertEquals(Constants.NDP_NODE_COUNT - 1, StorageEngineReader.recordPageOffset(1023));
   }
 
-  @Test(expected = IllegalStateException.class)
-  public void testGetValueFailsFastForUnsupportedFixedSlotMaterialization() {
-    final InternalResourceSession resourceManagerMock = createResourceManagerMock();
-    final ResourceConfiguration config = new ResourceConfiguration.Builder("foobar").build();
-
-    try (final var trx = new NodeStorageEngineReader(1, resourceManagerMock, new UberPage(), 0, mock(Reader.class),
-        mock(BufferManager.class), mock(RevisionRootPageReader.class), mock(TransactionIntentLog.class))) {
-      try (Arena arena = Arena.ofConfined()) {
-        final KeyValueLeafPage page =
-            new KeyValueLeafPage(0L, IndexType.DOCUMENT, config, 1, arena.allocate(SIXTYFOUR_KB), null);
-        try {
-          final long nodeKey = 7L;
-          final int slot = StorageEngineReader.recordPageOffset(nodeKey);
-          final int fixedSize = NodeKind.STRING_VALUE.layoutDescriptor().fixedSlotSizeInBytes();
-          page.setSlot(new byte[fixedSize], slot);
-          page.markSlotAsFixedFormat(slot, NodeKind.STRING_VALUE);
-
-          trx.getValue(page, nodeKey);
-        } finally {
-          page.close();
-        }
-      }
-    }
-  }
-
   @NonNull
   private InternalResourceSession createResourceManagerMock() {
     final var resourceManagerMock = mock(InternalResourceSession.class);
diff --git a/bundles/sirix-core/src/test/java/io/sirix/diff/DiffTestHelper.java b/bundles/sirix-core/src/test/java/io/sirix/diff/DiffTestHelper.java
index 7bb0ae884..18d814417 100644
--- a/bundles/sirix-core/src/test/java/io/sirix/diff/DiffTestHelper.java
+++ b/bundles/sirix-core/src/test/java/io/sirix/diff/DiffTestHelper.java
@@ -163,9 +163,7 @@ static void verifyOptimizedFullDiffFirst(final DiffObserver listener) {
            .diffListener(eq(DiffType.SAME), isA(Long.class), isA(Long.class), isA(DiffDepth.class));
     inOrder.verify(listener, times(2))
            .diffListener(eq(DiffType.INSERTED), isA(Long.class), isA(Long.class), isA(DiffDepth.class));
-    inOrder.verify(listener, times(1))
-           .diffListener(eq(DiffType.SAME), isA(Long.class), isA(Long.class), isA(DiffDepth.class));
-    inOrder.verify(listener, times(4))
+    inOrder.verify(listener, times(5))
            .diffListener(eq(DiffType.SAMEHASH), isA(Long.class), isA(Long.class), isA(DiffDepth.class));
     inOrder.verify(listener, times(1)).diffDone();
   }
@@ -187,9 +185,7 @@ static void verifyOptimizedStructuralDiffFirst(final DiffObserver listener) {
            .diffListener(eq(DiffType.SAME), isA(Long.class), isA(Long.class), isA(DiffDepth.class));
     inOrder.verify(listener, times(2))
            .diffListener(eq(DiffType.INSERTED), isA(Long.class), isA(Long.class), isA(DiffDepth.class));
-    inOrder.verify(listener, times(1))
-           .diffListener(eq(DiffType.SAME), isA(Long.class), isA(Long.class), isA(DiffDepth.class));
-    inOrder.verify(listener, times(4))
+    inOrder.verify(listener, times(5))
            .diffListener(eq(DiffType.SAMEHASH), isA(Long.class), isA(Long.class), isA(DiffDepth.class));
     inOrder.verify(listener, times(1)).diffDone();
   }
diff --git a/bundles/sirix-core/src/test/java/io/sirix/node/layout/CompactFieldCodecTest.java b/bundles/sirix-core/src/test/java/io/sirix/node/layout/CompactFieldCodecTest.java
deleted file mode 100644
index 6cd863b63..000000000
--- a/bundles/sirix-core/src/test/java/io/sirix/node/layout/CompactFieldCodecTest.java
+++ /dev/null
@@ -1,65 +0,0 @@
-package io.sirix.node.layout;
-
-import io.sirix.node.Bytes;
-import io.sirix.node.BytesIn;
-import io.sirix.node.BytesOut;
-import io.sirix.node.DeltaVarIntCodec;
-import io.sirix.settings.Fixed;
-import org.junit.jupiter.api.Test;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertThrows;
-
-final class CompactFieldCodecTest {
-
-  @Test
-  void signedIntegerRoundTrip() {
-    final int[] values = {Integer.MIN_VALUE, -1000, -1, 0, 1, 1000, Integer.MAX_VALUE};
-    for (final int value : values) {
-      final BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-      CompactFieldCodec.encodeSignedInt(sink, value);
-
-      final BytesIn source = Bytes.wrapForRead(sink.toByteArray());
-      assertEquals(value, CompactFieldCodec.decodeSignedInt(source), "Roundtrip mismatch for " + value);
-    }
-  }
-
-  @Test
-  void signedLongRoundTrip() {
-    final long[] values = {Long.MIN_VALUE, -1000L, -1L, 0L, 1L, 1000L, Long.MAX_VALUE};
-    for (final long value : values) {
-      final BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-      CompactFieldCodec.encodeSignedLong(sink, value);
-
-      final BytesIn source = Bytes.wrapForRead(sink.toByteArray());
-      assertEquals(value, CompactFieldCodec.decodeSignedLong(source), "Roundtrip mismatch for " + value);
-    }
-  }
-
-  @Test
-  void deltaNodeKeyRoundTripWithCornerCases() {
-    final long nullNodeKey = Fixed.NULL_NODE_KEY.getStandardProperty();
-    final long[][] cases = {{100L, 101L}, {100L, 99L}, {100L, 100L}, {100L, nullNodeKey},
-        {Long.MAX_VALUE - 2, Long.MAX_VALUE - 1}, {Long.MIN_VALUE + 2, Long.MIN_VALUE + 1}};
-
-    for (final long[] sample : cases) {
-      final long baseNodeKey = sample[0];
-      final long targetNodeKey = sample[1];
-
-      final BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-      CompactFieldCodec.encodeNodeKeyDelta(sink, baseNodeKey, targetNodeKey);
-
-      final BytesIn source = Bytes.wrapForRead(sink.toByteArray());
-      assertEquals(targetNodeKey, CompactFieldCodec.decodeNodeKeyDelta(source, baseNodeKey),
-          "Delta roundtrip mismatch for base=" + baseNodeKey + ", target=" + targetNodeKey);
-    }
-  }
-
-  @Test
-  void decodeNonNegativeRejectsNegativeNumbers() {
-    final BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    DeltaVarIntCodec.encodeSigned(sink, -1);
-    final BytesIn source = Bytes.wrapForRead(sink.toByteArray());
-    assertThrows(IllegalStateException.class, () -> CompactFieldCodec.decodeNonNegativeInt(source));
-  }
-}
diff --git a/bundles/sirix-core/src/test/java/io/sirix/node/layout/CompactPageEncoderTest.java b/bundles/sirix-core/src/test/java/io/sirix/node/layout/CompactPageEncoderTest.java
deleted file mode 100644
index 3955b2007..000000000
--- a/bundles/sirix-core/src/test/java/io/sirix/node/layout/CompactPageEncoderTest.java
+++ /dev/null
@@ -1,163 +0,0 @@
-package io.sirix.node.layout;
-
-import io.sirix.node.Bytes;
-import io.sirix.node.BytesIn;
-import io.sirix.node.BytesOut;
-import io.sirix.node.NodeKind;
-import io.sirix.settings.Fixed;
-import org.junit.jupiter.api.Test;
-
-import static org.junit.jupiter.api.Assertions.assertArrayEquals;
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertThrows;
-
-final class CompactPageEncoderTest {
-  private static final int LENGTH_LIMIT_PLUS_ONE = (1 << 20) + 1;
-
-  @Test
-  void slotHeaderRoundTrip() {
-    final CompactPageEncoder.SlotHeader header = new CompactPageEncoder.SlotHeader(42L, NodeKind.OBJECT, 96, 128);
-
-    final BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    CompactPageEncoder.encodeSlotHeader(sink, header);
-
-    final BytesIn source = Bytes.wrapForRead(sink.toByteArray());
-    final CompactPageEncoder.SlotHeader decoded = CompactPageEncoder.decodeSlotHeader(source);
-
-    assertEquals(header.nodeKey(), decoded.nodeKey());
-    assertEquals(header.nodeKind(), decoded.nodeKind());
-    assertEquals(header.fixedSlotSizeInBytes(), decoded.fixedSlotSizeInBytes());
-    assertEquals(header.payloadSizeInBytes(), decoded.payloadSizeInBytes());
-  }
-
-  @Test
-  void slotHeaderRoundTripWithReusableHeader() {
-    final CompactPageEncoder.SlotHeader header = new CompactPageEncoder.SlotHeader(73L, NodeKind.ELEMENT, 160, 256);
-
-    final BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    CompactPageEncoder.encodeSlotHeader(sink, header);
-
-    final CompactPageEncoder.MutableSlotHeader mutableHeader = new CompactPageEncoder.MutableSlotHeader();
-    final BytesIn source = Bytes.wrapForRead(sink.toByteArray());
-    CompactPageEncoder.decodeSlotHeader(source, mutableHeader);
-
-    assertEquals(header.nodeKey(), mutableHeader.nodeKey());
-    assertEquals(header.nodeKind(), mutableHeader.nodeKind());
-    assertEquals(header.fixedSlotSizeInBytes(), mutableHeader.fixedSlotSizeInBytes());
-    assertEquals(header.payloadSizeInBytes(), mutableHeader.payloadSizeInBytes());
-  }
-
-  @Test
-  void relationshipVectorRoundTripWithNullSentinel() {
-    final long baseNodeKey = 512L;
-    final long[] relationships = {513L, 511L, 512L, Fixed.NULL_NODE_KEY.getStandardProperty(), 600L};
-
-    final BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    CompactPageEncoder.encodeRelationshipVector(sink, baseNodeKey, relationships);
-
-    final BytesIn source = Bytes.wrapForRead(sink.toByteArray());
-    final long[] decoded = CompactPageEncoder.decodeRelationshipVector(source, baseNodeKey);
-    assertArrayEquals(relationships, decoded);
-  }
-
-  @Test
-  void relationshipVectorDecodesIntoReusableBuffer() {
-    final long baseNodeKey = 2048L;
-    final long[] relationships = {2049L, 2050L, 2047L};
-    final BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    CompactPageEncoder.encodeRelationshipVector(sink, baseNodeKey, relationships);
-
-    final long[] reusableBuffer = new long[8];
-    final BytesIn source = Bytes.wrapForRead(sink.toByteArray());
-    final int decodedLength = CompactPageEncoder.decodeRelationshipVector(source, baseNodeKey, reusableBuffer);
-
-    assertEquals(relationships.length, decodedLength);
-    for (int i = 0; i < decodedLength; i++) {
-      assertEquals(relationships[i], reusableBuffer[i]);
-    }
-  }
-
-  @Test
-  void decodeSlotHeaderRejectsUnknownNodeKind() {
-    final BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    CompactFieldCodec.encodeSignedLong(sink, 99L);
-    sink.writeByte((byte) 120);
-    CompactFieldCodec.encodeNonNegativeInt(sink, 16);
-    CompactFieldCodec.encodeNonNegativeInt(sink, 0);
-
-    final BytesIn source = Bytes.wrapForRead(sink.toByteArray());
-    assertThrows(IllegalStateException.class, () -> CompactPageEncoder.decodeSlotHeader(source));
-  }
-
-  @Test
-  void payloadBlockHeaderRoundTrip() {
-    final CompactPageEncoder.PayloadBlockHeader header = new CompactPageEncoder.PayloadBlockHeader(8192L, 1024, 5);
-
-    final BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    CompactPageEncoder.encodePayloadBlockHeader(sink, header);
-
-    final BytesIn source = Bytes.wrapForRead(sink.toByteArray());
-    final CompactPageEncoder.PayloadBlockHeader decoded = CompactPageEncoder.decodePayloadBlockHeader(source);
-
-    assertEquals(header.payloadPointer(), decoded.payloadPointer());
-    assertEquals(header.payloadLengthInBytes(), decoded.payloadLengthInBytes());
-    assertEquals(header.payloadFlags(), decoded.payloadFlags());
-  }
-
-  @Test
-  void payloadBlockHeaderRoundTripWithReusableHeader() {
-    final CompactPageEncoder.PayloadBlockHeader header = new CompactPageEncoder.PayloadBlockHeader(16384L, 2048, 9);
-
-    final BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    CompactPageEncoder.encodePayloadBlockHeader(sink, header);
-
-    final CompactPageEncoder.MutablePayloadBlockHeader mutableHeader =
-        new CompactPageEncoder.MutablePayloadBlockHeader();
-    final BytesIn source = Bytes.wrapForRead(sink.toByteArray());
-    CompactPageEncoder.decodePayloadBlockHeader(source, mutableHeader);
-
-    assertEquals(header.payloadPointer(), mutableHeader.payloadPointer());
-    assertEquals(header.payloadLengthInBytes(), mutableHeader.payloadLengthInBytes());
-    assertEquals(header.payloadFlags(), mutableHeader.payloadFlags());
-  }
-
-  @Test
-  void decodeRelationshipVectorRejectsInvalidLength() {
-    final BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    CompactFieldCodec.encodeSignedInt(sink, -1);
-    final BytesIn source = Bytes.wrapForRead(sink.toByteArray());
-    assertThrows(IllegalStateException.class, () -> CompactPageEncoder.decodeRelationshipVector(source, 10L));
-  }
-
-  @Test
-  void decodePayloadBlockHeaderRejectsNegativeLength() {
-    final BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    CompactFieldCodec.encodeSignedLong(sink, 123L);
-    CompactFieldCodec.encodeSignedInt(sink, -1);
-    CompactFieldCodec.encodeSignedInt(sink, 0);
-
-    final BytesIn source = Bytes.wrapForRead(sink.toByteArray());
-    assertThrows(IllegalStateException.class, () -> CompactPageEncoder.decodePayloadBlockHeader(source));
-  }
-
-  @Test
-  void decodeRelationshipVectorRejectsLengthOverLimit() {
-    final BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    CompactFieldCodec.encodeNonNegativeInt(sink, LENGTH_LIMIT_PLUS_ONE);
-    final BytesIn source = Bytes.wrapForRead(sink.toByteArray());
-    assertThrows(IllegalStateException.class, () -> CompactPageEncoder.decodeRelationshipVector(source, 10L));
-  }
-
-  @Test
-  void decodeRelationshipVectorIntoBufferRejectsInsufficientCapacity() {
-    final long baseNodeKey = 7L;
-    final long[] relationships = {8L, 9L, 10L};
-    final BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    CompactPageEncoder.encodeRelationshipVector(sink, baseNodeKey, relationships);
-
-    final BytesIn source = Bytes.wrapForRead(sink.toByteArray());
-    final long[] tooSmallBuffer = new long[2];
-    assertThrows(IllegalArgumentException.class,
-        () -> CompactPageEncoder.decodeRelationshipVector(source, baseNodeKey, tooSmallBuffer));
-  }
-}
diff --git a/bundles/sirix-core/src/test/java/io/sirix/node/layout/FixedSlotRecordProjectorTest.java b/bundles/sirix-core/src/test/java/io/sirix/node/layout/FixedSlotRecordProjectorTest.java
deleted file mode 100644
index d3666d361..000000000
--- a/bundles/sirix-core/src/test/java/io/sirix/node/layout/FixedSlotRecordProjectorTest.java
+++ /dev/null
@@ -1,595 +0,0 @@
-package io.sirix.node.layout;
-
-import io.brackit.query.atomic.QNm;
-import io.sirix.node.NodeKind;
-import io.sirix.node.MemorySegmentBytesIn;
-import io.sirix.node.json.BooleanNode;
-import io.sirix.node.json.NumberNode;
-import io.sirix.node.json.ObjectKeyNode;
-import io.sirix.node.json.ObjectNumberNode;
-import io.sirix.node.json.ObjectStringNode;
-import io.sirix.node.json.StringNode;
-import io.sirix.node.xml.AttributeNode;
-import io.sirix.node.xml.CommentNode;
-import io.sirix.node.xml.ElementNode;
-import io.sirix.node.xml.PINode;
-import io.sirix.node.xml.TextNode;
-import it.unimi.dsi.fastutil.longs.LongArrayList;
-import net.openhft.hashing.LongHashFunction;
-import org.junit.jupiter.api.Test;
-
-import java.lang.foreign.Arena;
-import java.lang.foreign.MemorySegment;
-import java.math.BigDecimal;
-import java.nio.charset.StandardCharsets;
-
-import static org.junit.jupiter.api.Assertions.assertArrayEquals;
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertFalse;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-
-class FixedSlotRecordProjectorTest {
-
-  @Test
-  void projectBooleanNodeIntoFixedSlot() {
-    final NodeKindLayout layout = NodeKindLayouts.layoutFor(NodeKind.BOOLEAN_VALUE);
-    final BooleanNode node =
-        new BooleanNode(42L, 7L, 11, 13, 17L, 19L, 23L, true, LongHashFunction.xx3(), (byte[]) null);
-
-    try (final Arena arena = Arena.ofConfined()) {
-      final MemorySegment slot = arena.allocate(layout.fixedSlotSizeInBytes());
-      final boolean projected = FixedSlotRecordProjector.project(node, layout, slot, 0L);
-
-      assertTrue(projected);
-      assertEquals(7L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.PARENT_KEY));
-      assertEquals(17L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.RIGHT_SIBLING_KEY));
-      assertEquals(19L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.LEFT_SIBLING_KEY));
-      assertEquals(11, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.PREVIOUS_REVISION));
-      assertEquals(13, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.LAST_MODIFIED_REVISION));
-      assertEquals(23L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.HASH));
-      assertTrue(SlotLayoutAccessors.readBooleanField(slot, layout, StructuralField.BOOLEAN_VALUE));
-    }
-  }
-
-  @Test
-  void projectObjectKeyNodeIntoFixedSlot() {
-    final NodeKindLayout layout = NodeKindLayouts.layoutFor(NodeKind.OBJECT_KEY);
-    final ObjectKeyNode node =
-        new ObjectKeyNode(128L, 3L, 5L, 8, 9, 11L, 13L, 17L, 19, 23L, 29L, LongHashFunction.xx3(), (byte[]) null);
-
-    try (final Arena arena = Arena.ofConfined()) {
-      final MemorySegment slot = arena.allocate(layout.fixedSlotSizeInBytes());
-      final boolean projected = FixedSlotRecordProjector.project(node, layout, slot, 0L);
-
-      assertTrue(projected);
-      assertEquals(3L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.PARENT_KEY));
-      assertEquals(11L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.RIGHT_SIBLING_KEY));
-      assertEquals(13L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.LEFT_SIBLING_KEY));
-      assertEquals(17L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.FIRST_CHILD_KEY));
-      assertEquals(17L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.LAST_CHILD_KEY));
-      assertEquals(5L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.PATH_NODE_KEY));
-      assertEquals(19, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.NAME_KEY));
-      assertEquals(8, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.PREVIOUS_REVISION));
-      assertEquals(9, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.LAST_MODIFIED_REVISION));
-      assertEquals(29L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.HASH));
-      assertEquals(23L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.DESCENDANT_COUNT));
-    }
-  }
-
-  @Test
-  void projectStringNodeRoundTrip() {
-    final NodeKindLayout layout = NodeKindLayouts.layoutFor(NodeKind.STRING_VALUE);
-    final byte[] value = "hello world".getBytes(StandardCharsets.UTF_8);
-    final StringNode node =
-        new StringNode(42L, 7L, 11, 13, 17L, 19L, 23L, value, LongHashFunction.xx3(), (byte[]) null);
-
-    final int inlinePayload = FixedSlotRecordProjector.computeInlinePayloadLength(node, layout);
-    assertEquals(value.length, inlinePayload);
-
-    final int totalSize = layout.fixedSlotSizeInBytes() + inlinePayload;
-
-    try (final Arena arena = Arena.ofConfined()) {
-      final MemorySegment slot = arena.allocate(totalSize);
-      final boolean projected = FixedSlotRecordProjector.project(node, layout, slot, 0L);
-
-      assertTrue(projected);
-
-      // Verify structural fields
-      assertEquals(7L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.PARENT_KEY));
-      assertEquals(17L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.RIGHT_SIBLING_KEY));
-      assertEquals(19L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.LEFT_SIBLING_KEY));
-      assertEquals(11, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.PREVIOUS_REVISION));
-      assertEquals(13, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.LAST_MODIFIED_REVISION));
-      assertEquals(23L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.HASH));
-
-      // Verify PayloadRef metadata
-      final long pointer = SlotLayoutAccessors.readPayloadPointer(slot, layout, 0);
-      final int length = SlotLayoutAccessors.readPayloadLength(slot, layout, 0);
-      final int flags = SlotLayoutAccessors.readPayloadFlags(slot, layout, 0);
-
-      assertEquals(layout.fixedSlotSizeInBytes(), (int) pointer);
-      assertEquals(value.length, length);
-      assertEquals(0, flags); // not compressed
-
-      // Verify inline payload bytes
-      final byte[] readValue = new byte[length];
-      MemorySegment.copy(slot, pointer, MemorySegment.ofArray(readValue), 0, length);
-      assertArrayEquals(value, readValue);
-    }
-  }
-
-  @Test
-  void projectObjectStringNodeRoundTrip() {
-    final NodeKindLayout layout = NodeKindLayouts.layoutFor(NodeKind.OBJECT_STRING_VALUE);
-    final byte[] value = "test value".getBytes(StandardCharsets.UTF_8);
-    final ObjectStringNode node =
-        new ObjectStringNode(42L, 7L, 11, 13, 23L, value, LongHashFunction.xx3(), (byte[]) null);
-
-    final int inlinePayload = FixedSlotRecordProjector.computeInlinePayloadLength(node, layout);
-    assertEquals(value.length, inlinePayload);
-
-    final int totalSize = layout.fixedSlotSizeInBytes() + inlinePayload;
-
-    try (final Arena arena = Arena.ofConfined()) {
-      final MemorySegment slot = arena.allocate(totalSize);
-      final boolean projected = FixedSlotRecordProjector.project(node, layout, slot, 0L);
-
-      assertTrue(projected);
-
-      // Verify structural fields
-      assertEquals(7L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.PARENT_KEY));
-      assertEquals(11, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.PREVIOUS_REVISION));
-      assertEquals(13, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.LAST_MODIFIED_REVISION));
-      assertEquals(23L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.HASH));
-
-      // Verify inline payload bytes
-      final int length = SlotLayoutAccessors.readPayloadLength(slot, layout, 0);
-      final long pointer = SlotLayoutAccessors.readPayloadPointer(slot, layout, 0);
-      final byte[] readValue = new byte[length];
-      MemorySegment.copy(slot, pointer, MemorySegment.ofArray(readValue), 0, length);
-      assertArrayEquals(value, readValue);
-    }
-  }
-
-  @Test
-  void projectNumberNodeRoundTrip() {
-    final NodeKindLayout layout = NodeKindLayouts.layoutFor(NodeKind.NUMBER_VALUE);
-    final NumberNode node = new NumberNode(42L, 7L, 11, 13, 17L, 19L, 23L, 42.5, LongHashFunction.xx3(), (byte[]) null);
-
-    final int inlinePayload = FixedSlotRecordProjector.computeInlinePayloadLength(node, layout);
-    assertTrue(inlinePayload > 0);
-
-    final int totalSize = layout.fixedSlotSizeInBytes() + inlinePayload;
-
-    try (final Arena arena = Arena.ofConfined()) {
-      final MemorySegment slot = arena.allocate(totalSize);
-      final boolean projected = FixedSlotRecordProjector.project(node, layout, slot, 0L);
-
-      assertTrue(projected);
-
-      // Verify structural fields
-      assertEquals(7L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.PARENT_KEY));
-      assertEquals(17L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.RIGHT_SIBLING_KEY));
-      assertEquals(19L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.LEFT_SIBLING_KEY));
-      assertEquals(23L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.HASH));
-
-      // Verify PayloadRef metadata
-      final long pointer = SlotLayoutAccessors.readPayloadPointer(slot, layout, 0);
-      final int length = SlotLayoutAccessors.readPayloadLength(slot, layout, 0);
-      assertEquals(layout.fixedSlotSizeInBytes(), (int) pointer);
-      assertTrue(length > 0);
-
-      // Verify inline payload can be deserialized back to number
-      final MemorySegment payloadSlice = slot.asSlice(pointer, length);
-      final Number deserialized = NodeKind.deserializeNumber(new MemorySegmentBytesIn(payloadSlice));
-      assertEquals(42.5, deserialized.doubleValue(), 0.0001);
-    }
-  }
-
-  @Test
-  void projectObjectNumberNodeRoundTrip() {
-    final NodeKindLayout layout = NodeKindLayouts.layoutFor(NodeKind.OBJECT_NUMBER_VALUE);
-    final ObjectNumberNode node =
-        new ObjectNumberNode(42L, 7L, 11, 13, 23L, 123, LongHashFunction.xx3(), (byte[]) null);
-
-    final int inlinePayload = FixedSlotRecordProjector.computeInlinePayloadLength(node, layout);
-    assertTrue(inlinePayload > 0);
-
-    final int totalSize = layout.fixedSlotSizeInBytes() + inlinePayload;
-
-    try (final Arena arena = Arena.ofConfined()) {
-      final MemorySegment slot = arena.allocate(totalSize);
-      final boolean projected = FixedSlotRecordProjector.project(node, layout, slot, 0L);
-
-      assertTrue(projected);
-
-      // Verify inline payload can be deserialized back to number
-      final long pointer = SlotLayoutAccessors.readPayloadPointer(slot, layout, 0);
-      final int length = SlotLayoutAccessors.readPayloadLength(slot, layout, 0);
-      final MemorySegment payloadSlice = slot.asSlice(pointer, length);
-      final Number deserialized = NodeKind.deserializeNumber(new MemorySegmentBytesIn(payloadSlice));
-      assertEquals(123, deserialized.intValue());
-    }
-  }
-
-  @Test
-  void projectNumberNodeBigDecimalRoundTrip() {
-    final NodeKindLayout layout = NodeKindLayouts.layoutFor(NodeKind.NUMBER_VALUE);
-    final BigDecimal bigDecimalValue = new BigDecimal("12345678901234567890.12345");
-    final NumberNode node =
-        new NumberNode(42L, 7L, 11, 13, 17L, 19L, 23L, bigDecimalValue, LongHashFunction.xx3(), (byte[]) null);
-
-    final int inlinePayload = FixedSlotRecordProjector.computeInlinePayloadLength(node, layout);
-    assertTrue(inlinePayload > 0);
-
-    final int totalSize = layout.fixedSlotSizeInBytes() + inlinePayload;
-
-    try (final Arena arena = Arena.ofConfined()) {
-      final MemorySegment slot = arena.allocate(totalSize);
-      assertTrue(FixedSlotRecordProjector.project(node, layout, slot, 0L));
-
-      final long pointer = SlotLayoutAccessors.readPayloadPointer(slot, layout, 0);
-      final int length = SlotLayoutAccessors.readPayloadLength(slot, layout, 0);
-      final MemorySegment payloadSlice = slot.asSlice(pointer, length);
-      final Number deserialized = NodeKind.deserializeNumber(new MemorySegmentBytesIn(payloadSlice));
-      assertEquals(bigDecimalValue, deserialized);
-    }
-  }
-
-  @Test
-  void projectCompressedStringPreservesFlags() {
-    final NodeKindLayout layout = NodeKindLayouts.layoutFor(NodeKind.STRING_VALUE);
-    final byte[] rawCompressed = {0x01, 0x02, 0x03, 0x04};
-    final StringNode node = new StringNode(42L, 7L, 11, 13, 17L, 19L, 23L, rawCompressed, LongHashFunction.xx3(),
-        (byte[]) null, true, null);
-
-    final int inlinePayload = FixedSlotRecordProjector.computeInlinePayloadLength(node, layout);
-    final int totalSize = layout.fixedSlotSizeInBytes() + inlinePayload;
-
-    try (final Arena arena = Arena.ofConfined()) {
-      final MemorySegment slot = arena.allocate(totalSize);
-      assertTrue(FixedSlotRecordProjector.project(node, layout, slot, 0L));
-
-      final int flags = SlotLayoutAccessors.readPayloadFlags(slot, layout, 0);
-      assertEquals(1, flags); // compressed flag set
-    }
-  }
-
-  @Test
-  void hasSupportedPayloadsReturnsTrueForValueBlob() {
-    final NodeKindLayout stringLayout = NodeKindLayouts.layoutFor(NodeKind.STRING_VALUE);
-    assertTrue(FixedSlotRecordProjector.hasSupportedPayloads(stringLayout));
-
-    final NodeKindLayout booleanLayout = NodeKindLayouts.layoutFor(NodeKind.BOOLEAN_VALUE);
-    assertTrue(FixedSlotRecordProjector.hasSupportedPayloads(booleanLayout));
-  }
-
-  @Test
-  void computeInlinePayloadLengthReturnsZeroForNonPayloadNodes() {
-    final NodeKindLayout layout = NodeKindLayouts.layoutFor(NodeKind.BOOLEAN_VALUE);
-    final BooleanNode node = new BooleanNode(1L, 2L, 3, 4, 5L, 6L, 7L, false, LongHashFunction.xx3(), (byte[]) null);
-    assertEquals(0, FixedSlotRecordProjector.computeInlinePayloadLength(node, layout));
-  }
-
-  @Test
-  void projectTextNodeRoundTrip() {
-    final NodeKindLayout layout = NodeKindLayouts.layoutFor(NodeKind.TEXT);
-    final byte[] value = "hello xml text".getBytes(StandardCharsets.UTF_8);
-    final TextNode node =
-        new TextNode(42L, 7L, 11, 13, 17L, 19L, 23L, value, false, LongHashFunction.xx3(), (byte[]) null);
-
-    final int inlinePayload = FixedSlotRecordProjector.computeInlinePayloadLength(node, layout);
-    assertEquals(value.length, inlinePayload);
-
-    final int totalSize = layout.fixedSlotSizeInBytes() + inlinePayload;
-
-    try (final Arena arena = Arena.ofConfined()) {
-      final MemorySegment slot = arena.allocate(totalSize);
-      final boolean projected = FixedSlotRecordProjector.project(node, layout, slot, 0L);
-
-      assertTrue(projected);
-
-      // Verify structural fields
-      assertEquals(7L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.PARENT_KEY));
-      assertEquals(17L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.RIGHT_SIBLING_KEY));
-      assertEquals(19L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.LEFT_SIBLING_KEY));
-      assertEquals(11, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.PREVIOUS_REVISION));
-      assertEquals(13, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.LAST_MODIFIED_REVISION));
-
-      // Verify PayloadRef metadata
-      final long pointer = SlotLayoutAccessors.readPayloadPointer(slot, layout, 0);
-      final int length = SlotLayoutAccessors.readPayloadLength(slot, layout, 0);
-      final int flags = SlotLayoutAccessors.readPayloadFlags(slot, layout, 0);
-
-      assertEquals(layout.fixedSlotSizeInBytes(), (int) pointer);
-      assertEquals(value.length, length);
-      assertEquals(0, flags); // not compressed
-
-      // Verify inline payload bytes
-      final byte[] readValue = new byte[length];
-      MemorySegment.copy(slot, pointer, MemorySegment.ofArray(readValue), 0, length);
-      assertArrayEquals(value, readValue);
-    }
-  }
-
-  @Test
-  void projectTextNodeCompressedRoundTrip() {
-    final NodeKindLayout layout = NodeKindLayouts.layoutFor(NodeKind.TEXT);
-    final byte[] rawCompressed = {0x01, 0x02, 0x03, 0x04};
-    final TextNode node =
-        new TextNode(42L, 7L, 11, 13, 17L, 19L, 23L, rawCompressed, true, LongHashFunction.xx3(), (byte[]) null);
-
-    final int inlinePayload = FixedSlotRecordProjector.computeInlinePayloadLength(node, layout);
-    final int totalSize = layout.fixedSlotSizeInBytes() + inlinePayload;
-
-    try (final Arena arena = Arena.ofConfined()) {
-      final MemorySegment slot = arena.allocate(totalSize);
-      assertTrue(FixedSlotRecordProjector.project(node, layout, slot, 0L));
-
-      final int flags = SlotLayoutAccessors.readPayloadFlags(slot, layout, 0);
-      assertEquals(1, flags); // compressed flag set
-    }
-  }
-
-  @Test
-  void projectCommentNodeRoundTrip() {
-    final NodeKindLayout layout = NodeKindLayouts.layoutFor(NodeKind.COMMENT);
-    final byte[] value = "a comment".getBytes(StandardCharsets.UTF_8);
-    final CommentNode node =
-        new CommentNode(42L, 7L, 11, 13, 17L, 19L, 23L, value, false, LongHashFunction.xx3(), (byte[]) null);
-
-    final int inlinePayload = FixedSlotRecordProjector.computeInlinePayloadLength(node, layout);
-    assertEquals(value.length, inlinePayload);
-
-    final int totalSize = layout.fixedSlotSizeInBytes() + inlinePayload;
-
-    try (final Arena arena = Arena.ofConfined()) {
-      final MemorySegment slot = arena.allocate(totalSize);
-      assertTrue(FixedSlotRecordProjector.project(node, layout, slot, 0L));
-
-      assertEquals(7L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.PARENT_KEY));
-      assertEquals(17L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.RIGHT_SIBLING_KEY));
-      assertEquals(19L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.LEFT_SIBLING_KEY));
-      assertEquals(11, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.PREVIOUS_REVISION));
-      assertEquals(13, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.LAST_MODIFIED_REVISION));
-
-      final int length = SlotLayoutAccessors.readPayloadLength(slot, layout, 0);
-      final long pointer = SlotLayoutAccessors.readPayloadPointer(slot, layout, 0);
-      final byte[] readValue = new byte[length];
-      MemorySegment.copy(slot, pointer, MemorySegment.ofArray(readValue), 0, length);
-      assertArrayEquals(value, readValue);
-    }
-  }
-
-  @Test
-  void projectAttributeNodeRoundTrip() {
-    final NodeKindLayout layout = NodeKindLayouts.layoutFor(NodeKind.ATTRIBUTE);
-    final byte[] value = "attr-value".getBytes(StandardCharsets.UTF_8);
-    final QNm qNm = new QNm("ns", "prefix", "local");
-    final AttributeNode node =
-        new AttributeNode(42L, 7L, 11, 13, 5L, 100, 200, 300, 23L, value, LongHashFunction.xx3(), (byte[]) null, qNm);
-
-    final int inlinePayload = FixedSlotRecordProjector.computeInlinePayloadLength(node, layout);
-    assertEquals(value.length, inlinePayload);
-
-    final int totalSize = layout.fixedSlotSizeInBytes() + inlinePayload;
-
-    try (final Arena arena = Arena.ofConfined()) {
-      final MemorySegment slot = arena.allocate(totalSize);
-      assertTrue(FixedSlotRecordProjector.project(node, layout, slot, 0L));
-
-      assertEquals(7L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.PARENT_KEY));
-      assertEquals(5L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.PATH_NODE_KEY));
-      assertEquals(100, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.PREFIX_KEY));
-      assertEquals(200, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.LOCAL_NAME_KEY));
-      assertEquals(300, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.URI_KEY));
-      assertEquals(11, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.PREVIOUS_REVISION));
-      assertEquals(13, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.LAST_MODIFIED_REVISION));
-
-      final int flags = SlotLayoutAccessors.readPayloadFlags(slot, layout, 0);
-      assertEquals(0, flags); // attributes never compressed
-
-      final int length = SlotLayoutAccessors.readPayloadLength(slot, layout, 0);
-      final long pointer = SlotLayoutAccessors.readPayloadPointer(slot, layout, 0);
-      final byte[] readValue = new byte[length];
-      MemorySegment.copy(slot, pointer, MemorySegment.ofArray(readValue), 0, length);
-      assertArrayEquals(value, readValue);
-    }
-  }
-
-  @Test
-  void projectPINodeRoundTrip() {
-    final NodeKindLayout layout = NodeKindLayouts.layoutFor(NodeKind.PROCESSING_INSTRUCTION);
-    final byte[] value = "pi-target data".getBytes(StandardCharsets.UTF_8);
-    final QNm qNm = new QNm("", "", "xml-stylesheet");
-    final PINode node = new PINode(42L, 7L, 11, 13, 17L, 19L, 31L, 37L, 3, 5, 23L, 41L, 100, 200, 300, value, false,
-        LongHashFunction.xx3(), (byte[]) null, qNm);
-
-    final int inlinePayload = FixedSlotRecordProjector.computeInlinePayloadLength(node, layout);
-    assertEquals(value.length, inlinePayload);
-
-    final int totalSize = layout.fixedSlotSizeInBytes() + inlinePayload;
-
-    try (final Arena arena = Arena.ofConfined()) {
-      final MemorySegment slot = arena.allocate(totalSize);
-      assertTrue(FixedSlotRecordProjector.project(node, layout, slot, 0L));
-
-      // Verify structural fields
-      assertEquals(7L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.PARENT_KEY));
-      assertEquals(17L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.RIGHT_SIBLING_KEY));
-      assertEquals(19L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.LEFT_SIBLING_KEY));
-      assertEquals(31L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.FIRST_CHILD_KEY));
-      assertEquals(37L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.LAST_CHILD_KEY));
-      assertEquals(3L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.CHILD_COUNT));
-      assertEquals(5L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.DESCENDANT_COUNT));
-
-      // Verify name fields
-      assertEquals(41L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.PATH_NODE_KEY));
-      assertEquals(100, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.PREFIX_KEY));
-      assertEquals(200, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.LOCAL_NAME_KEY));
-      assertEquals(300, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.URI_KEY));
-
-      assertEquals(11, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.PREVIOUS_REVISION));
-      assertEquals(13, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.LAST_MODIFIED_REVISION));
-
-      // Verify inline payload bytes
-      final int length = SlotLayoutAccessors.readPayloadLength(slot, layout, 0);
-      final long pointer = SlotLayoutAccessors.readPayloadPointer(slot, layout, 0);
-      final byte[] readValue = new byte[length];
-      MemorySegment.copy(slot, pointer, MemorySegment.ofArray(readValue), 0, length);
-      assertArrayEquals(value, readValue);
-    }
-  }
-
-  @Test
-  void hasSupportedPayloadsAcceptsVectorPayloadRefs() {
-    final NodeKindLayout layoutWithAttrs = NodeKindLayout.builder(NodeKind.ELEMENT)
-                                                         .addField(StructuralField.PARENT_KEY)
-                                                         .addField(StructuralField.HASH)
-                                                         .addPayloadRef("attrs", PayloadRefKind.ATTRIBUTE_VECTOR)
-                                                         .build();
-
-    assertTrue(FixedSlotRecordProjector.hasSupportedPayloads(layoutWithAttrs));
-
-    // project() should reject a type mismatch (BooleanNode for ELEMENT layout)
-    final BooleanNode node = new BooleanNode(1L, 2L, 3, 4, 5L, 6L, 7L, false, LongHashFunction.xx3(), (byte[]) null);
-
-    try (final Arena arena = Arena.ofConfined()) {
-      final MemorySegment slot = arena.allocate(Math.max(layoutWithAttrs.fixedSlotSizeInBytes(), 128));
-      assertFalse(FixedSlotRecordProjector.project(node, layoutWithAttrs, slot, 0L));
-    }
-  }
-
-  @Test
-  void elementNodeRoundTripWithAttributesAndNamespaces() {
-    final NodeKindLayout layout = NodeKindLayouts.layoutFor(NodeKind.ELEMENT);
-    final LongHashFunction hashFunction = LongHashFunction.xx3();
-    final QNm qNm = new QNm("ns", "pfx", "local");
-
-    final LongArrayList attrKeys = new LongArrayList(new long[] {100L, 200L, 300L});
-    final LongArrayList nsKeys = new LongArrayList(new long[] {400L, 500L});
-
-    final ElementNode node = new ElementNode(42L, 10L, 3, 7, 20L, 30L, 40L, 50L, 5L, 100L, 999L, 60L, 11, 22, 33,
-        hashFunction, (byte[]) null, attrKeys, nsKeys, qNm);
-
-    try (final Arena arena = Arena.ofConfined()) {
-      final int totalSize =
-          layout.fixedSlotSizeInBytes() + node.getAttributeCount() * Long.BYTES + node.getNamespaceCount() * Long.BYTES;
-      final MemorySegment slot = arena.allocate(totalSize);
-      assertTrue(FixedSlotRecordProjector.project(node, layout, slot, 0L));
-
-      // Verify structural fields
-      assertEquals(10L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.PARENT_KEY));
-      assertEquals(20L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.RIGHT_SIBLING_KEY));
-      assertEquals(30L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.LEFT_SIBLING_KEY));
-      assertEquals(40L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.FIRST_CHILD_KEY));
-      assertEquals(50L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.LAST_CHILD_KEY));
-      assertEquals(60L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.PATH_NODE_KEY));
-      assertEquals(11, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.PREFIX_KEY));
-      assertEquals(22, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.LOCAL_NAME_KEY));
-      assertEquals(33, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.URI_KEY));
-      assertEquals(3, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.PREVIOUS_REVISION));
-      assertEquals(7, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.LAST_MODIFIED_REVISION));
-      assertEquals(999L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.HASH));
-      assertEquals(5L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.CHILD_COUNT));
-      assertEquals(100L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.DESCENDANT_COUNT));
-
-      // Verify attribute vector payload
-      assertEquals(3 * Long.BYTES, SlotLayoutAccessors.readPayloadLength(slot, layout, 0));
-      // Verify namespace vector payload
-      assertEquals(2 * Long.BYTES, SlotLayoutAccessors.readPayloadLength(slot, layout, 1));
-
-      // Populate existing singleton from projected slot
-      final ElementNode populated = new ElementNode(0L, 0L, 0, 0, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0, 0, 0, hashFunction,
-          (byte[]) null, new LongArrayList(), new LongArrayList(), new QNm(""));
-      assertTrue(FixedSlotRecordMaterializer.populateExisting(populated, NodeKind.ELEMENT, 42L, slot, 0L,
-          (int) slot.byteSize(), null, null));
-      assertEquals(42L, populated.getNodeKey());
-      assertEquals(10L, populated.getParentKey());
-      assertEquals(20L, populated.getRightSiblingKey());
-      assertEquals(30L, populated.getLeftSiblingKey());
-      assertEquals(40L, populated.getFirstChildKey());
-      assertEquals(50L, populated.getLastChildKey());
-      assertEquals(60L, populated.getPathNodeKey());
-      assertEquals(11, populated.getPrefixKey());
-      assertEquals(22, populated.getLocalNameKey());
-      assertEquals(33, populated.getURIKey());
-      assertEquals(3, populated.getPreviousRevisionNumber());
-      assertEquals(7, populated.getLastModifiedRevisionNumber());
-      assertEquals(999L, populated.getHash());
-      assertEquals(5L, populated.getChildCount());
-      assertEquals(100L, populated.getDescendantCount());
-      assertEquals(3, populated.getAttributeCount());
-      assertEquals(100L, populated.getAttributeKey(0));
-      assertEquals(200L, populated.getAttributeKey(1));
-      assertEquals(300L, populated.getAttributeKey(2));
-      assertEquals(2, populated.getNamespaceCount());
-      assertEquals(400L, populated.getNamespaceKey(0));
-      assertEquals(500L, populated.getNamespaceKey(1));
-    }
-  }
-
-  @Test
-  void elementNodeRoundTripWithEmptyVectors() {
-    final NodeKindLayout layout = NodeKindLayouts.layoutFor(NodeKind.ELEMENT);
-    final LongHashFunction hashFunction = LongHashFunction.xx3();
-
-    final ElementNode node = new ElementNode(1L, 2L, 1, 1, 3L, 4L, 5L, 6L, 0L, 0L, 0L, 7L, 0, 0, 0, hashFunction,
-        (byte[]) null, new LongArrayList(), new LongArrayList(), new QNm(""));
-
-    try (final Arena arena = Arena.ofConfined()) {
-      final MemorySegment slot = arena.allocate(layout.fixedSlotSizeInBytes());
-      assertTrue(FixedSlotRecordProjector.project(node, layout, slot, 0L));
-
-      assertEquals(0, SlotLayoutAccessors.readPayloadLength(slot, layout, 0));
-      assertEquals(0, SlotLayoutAccessors.readPayloadLength(slot, layout, 1));
-
-      final ElementNode populated = new ElementNode(0L, 0L, 0, 0, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0, 0, 0, hashFunction,
-          (byte[]) null, new LongArrayList(), new LongArrayList(), new QNm(""));
-      assertTrue(FixedSlotRecordMaterializer.populateExisting(populated, NodeKind.ELEMENT, 1L, slot, 0L,
-          (int) slot.byteSize(), null, null));
-      assertEquals(0, populated.getAttributeCount());
-      assertEquals(0, populated.getNamespaceCount());
-      assertEquals(2L, populated.getParentKey());
-    }
-  }
-
-  @Test
-  void elementNodePopulateExistingRoundTrip() {
-    final NodeKindLayout layout = NodeKindLayouts.layoutFor(NodeKind.ELEMENT);
-    final LongHashFunction hashFunction = LongHashFunction.xx3();
-
-    final LongArrayList attrKeys = new LongArrayList(new long[] {10L, 20L});
-    final LongArrayList nsKeys = new LongArrayList(new long[] {30L});
-
-    final ElementNode original = new ElementNode(5L, 100L, 2, 4, 101L, 102L, 103L, 104L, 3L, 50L, 777L, 105L, 8, 9, 10,
-        hashFunction, (byte[]) null, attrKeys, nsKeys, new QNm(""));
-
-    try (final Arena arena = Arena.ofConfined()) {
-      final int totalSize = layout.fixedSlotSizeInBytes() + original.getAttributeCount() * Long.BYTES
-          + original.getNamespaceCount() * Long.BYTES;
-      final MemorySegment slot = arena.allocate(totalSize);
-      assertTrue(FixedSlotRecordProjector.project(original, layout, slot, 0L));
-
-      // Populate into an existing singleton
-      final ElementNode singleton = new ElementNode(0L, 0L, 0, 0, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0, 0, 0, hashFunction,
-          (byte[]) null, new LongArrayList(), new LongArrayList(), new QNm(""));
-
-      assertTrue(FixedSlotRecordMaterializer.populateExisting(singleton, NodeKind.ELEMENT, 5L, slot, 0L,
-          (int) slot.byteSize(), null, null));
-
-      assertEquals(5L, singleton.getNodeKey());
-      assertEquals(100L, singleton.getParentKey());
-      assertEquals(101L, singleton.getRightSiblingKey());
-      assertEquals(102L, singleton.getLeftSiblingKey());
-      assertEquals(103L, singleton.getFirstChildKey());
-      assertEquals(104L, singleton.getLastChildKey());
-      assertEquals(777L, singleton.getHash());
-      assertEquals(2, singleton.getAttributeCount());
-      assertEquals(10L, singleton.getAttributeKey(0));
-      assertEquals(20L, singleton.getAttributeKey(1));
-      assertEquals(1, singleton.getNamespaceCount());
-      assertEquals(30L, singleton.getNamespaceKey(0));
-    }
-  }
-}
diff --git a/bundles/sirix-core/src/test/java/io/sirix/node/layout/NodeKindLayoutsTest.java b/bundles/sirix-core/src/test/java/io/sirix/node/layout/NodeKindLayoutsTest.java
deleted file mode 100644
index 470cb360f..000000000
--- a/bundles/sirix-core/src/test/java/io/sirix/node/layout/NodeKindLayoutsTest.java
+++ /dev/null
@@ -1,85 +0,0 @@
-package io.sirix.node.layout;
-
-import io.sirix.node.NodeKind;
-import org.junit.jupiter.api.Test;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertFalse;
-import static org.junit.jupiter.api.Assertions.assertNotNull;
-import static org.junit.jupiter.api.Assertions.assertSame;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-
-final class NodeKindLayoutsTest {
-
-  @Test
-  void xmlAndJsonCoreKindsExposeFixedLayouts() {
-    final NodeKind[] fixedKinds = {NodeKind.XML_DOCUMENT, NodeKind.ELEMENT, NodeKind.ATTRIBUTE, NodeKind.NAMESPACE,
-        NodeKind.TEXT, NodeKind.COMMENT, NodeKind.PROCESSING_INSTRUCTION, NodeKind.JSON_DOCUMENT, NodeKind.OBJECT,
-        NodeKind.ARRAY, NodeKind.OBJECT_KEY, NodeKind.STRING_VALUE, NodeKind.NUMBER_VALUE, NodeKind.BOOLEAN_VALUE,
-        NodeKind.NULL_VALUE, NodeKind.OBJECT_STRING_VALUE, NodeKind.OBJECT_NUMBER_VALUE, NodeKind.OBJECT_BOOLEAN_VALUE,
-        NodeKind.OBJECT_NULL_VALUE};
-
-    for (final NodeKind kind : fixedKinds) {
-      final NodeKindLayout layout = NodeKindLayouts.layoutFor(kind);
-      assertTrue(layout.isFixedSlotSupported(), "Expected fixed-slot support for: " + kind);
-      assertTrue(layout.fixedSlotSizeInBytes() > 0, "Expected non-zero slot size for: " + kind);
-      assertSame(layout, kind.layoutDescriptor(), "NodeKind should delegate to registry for: " + kind);
-      assertTrue(kind.hasFixedSlotLayout(), "NodeKind should expose fixed-slot support for: " + kind);
-      assertEquals(layout.fixedSlotSizeInBytes(), kind.fixedSlotSizeInBytes(),
-          "NodeKind should expose fixed-slot size for: " + kind);
-    }
-  }
-
-  @Test
-  void unsupportedKindsRemainMarkedUnsupported() {
-    final NodeKindLayout pathLayout = NodeKindLayouts.layoutFor(NodeKind.PATH);
-    assertFalse(pathLayout.isFixedSlotSupported());
-    assertTrue(pathLayout.fixedSlotSizeInBytes() == 0);
-    assertTrue(pathLayout.payloadRefCount() == 0);
-    assertFalse(NodeKind.PATH.hasFixedSlotLayout());
-    assertEquals(0, NodeKind.PATH.fixedSlotSizeInBytes());
-  }
-
-  @Test
-  void fixedSlotContractsHaveNoOverlappingRanges() {
-    for (final NodeKind kind : NodeKind.values()) {
-      final NodeKindLayout layout = NodeKindLayouts.layoutFor(kind);
-      if (!layout.isFixedSlotSupported()) {
-        continue;
-      }
-
-      final int slotSize = layout.fixedSlotSizeInBytes();
-      final boolean[] occupied = new boolean[slotSize];
-
-      for (final StructuralField field : StructuralField.values()) {
-        final int offset = layout.offsetOfOrMinusOne(field);
-        if (offset < 0) {
-          continue;
-        }
-        assertTrue(offset + field.widthInBytes() <= slotSize, "Field exceeds slot boundary: " + kind + "/" + field);
-        markRangeFreeThenOccupy(occupied, offset, field.widthInBytes(), kind + "/" + field);
-      }
-
-      for (int i = 0; i < layout.payloadRefCount(); i++) {
-        final PayloadRef payloadRef = layout.payloadRef(i);
-        assertNotNull(payloadRef);
-        markRangeFreeThenOccupy(occupied, payloadRef.pointerOffset(), PayloadRef.POINTER_WIDTH_BYTES,
-            kind + "/" + payloadRef.name() + "#ptr");
-        markRangeFreeThenOccupy(occupied, payloadRef.lengthOffset(), PayloadRef.LENGTH_WIDTH_BYTES,
-            kind + "/" + payloadRef.name() + "#len");
-        markRangeFreeThenOccupy(occupied, payloadRef.flagsOffset(), PayloadRef.FLAGS_WIDTH_BYTES,
-            kind + "/" + payloadRef.name() + "#flags");
-      }
-    }
-  }
-
-  private static void markRangeFreeThenOccupy(final boolean[] occupied, final int offset, final int width,
-      final String label) {
-    assertTrue(offset >= 0, "Negative offset for: " + label);
-    assertTrue(offset + width <= occupied.length, "Out-of-bounds range for: " + label);
-    for (int i = offset; i < offset + width; i++) {
-      assertFalse(occupied[i], "Overlapping byte in slot layout for: " + label);
-      occupied[i] = true;
-    }
-  }
-}
diff --git a/bundles/sirix-core/src/test/java/io/sirix/node/layout/SlotLayoutAccessorsTest.java b/bundles/sirix-core/src/test/java/io/sirix/node/layout/SlotLayoutAccessorsTest.java
deleted file mode 100644
index bddb5bbcf..000000000
--- a/bundles/sirix-core/src/test/java/io/sirix/node/layout/SlotLayoutAccessorsTest.java
+++ /dev/null
@@ -1,89 +0,0 @@
-package io.sirix.node.layout;
-
-import io.sirix.node.NodeKind;
-import org.junit.jupiter.api.Test;
-
-import java.lang.foreign.Arena;
-import java.lang.foreign.MemorySegment;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertFalse;
-import static org.junit.jupiter.api.Assertions.assertThrows;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-
-final class SlotLayoutAccessorsTest {
-
-  @Test
-  void longAndIntFieldRoundTrip() {
-    final NodeKindLayout layout = NodeKindLayouts.layoutFor(NodeKind.OBJECT);
-    try (Arena arena = Arena.ofConfined()) {
-      final MemorySegment slot = arena.allocate(layout.fixedSlotSizeInBytes());
-
-      SlotLayoutAccessors.writeLongField(slot, layout, StructuralField.PARENT_KEY, 100L);
-      SlotLayoutAccessors.writeLongField(slot, layout, StructuralField.FIRST_CHILD_KEY, 101L);
-      SlotLayoutAccessors.writeIntField(slot, layout, StructuralField.PREVIOUS_REVISION, 7);
-
-      assertEquals(100L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.PARENT_KEY));
-      assertEquals(101L, SlotLayoutAccessors.readLongField(slot, layout, StructuralField.FIRST_CHILD_KEY));
-      assertEquals(7, SlotLayoutAccessors.readIntField(slot, layout, StructuralField.PREVIOUS_REVISION));
-    }
-  }
-
-  @Test
-  void booleanFieldRoundTrip() {
-    final NodeKindLayout layout = NodeKindLayouts.layoutFor(NodeKind.BOOLEAN_VALUE);
-    try (Arena arena = Arena.ofConfined()) {
-      final MemorySegment slot = arena.allocate(layout.fixedSlotSizeInBytes());
-
-      SlotLayoutAccessors.writeBooleanField(slot, layout, StructuralField.BOOLEAN_VALUE, true);
-      assertTrue(SlotLayoutAccessors.readBooleanField(slot, layout, StructuralField.BOOLEAN_VALUE));
-
-      SlotLayoutAccessors.writeBooleanField(slot, layout, StructuralField.BOOLEAN_VALUE, false);
-      assertFalse(SlotLayoutAccessors.readBooleanField(slot, layout, StructuralField.BOOLEAN_VALUE));
-    }
-  }
-
-  @Test
-  void payloadRefRoundTrip() {
-    final NodeKindLayout layout = NodeKindLayouts.layoutFor(NodeKind.STRING_VALUE);
-    try (Arena arena = Arena.ofConfined()) {
-      final MemorySegment slot = arena.allocate(layout.fixedSlotSizeInBytes());
-      SlotLayoutAccessors.writePayloadRef(slot, layout, 0, 4096L, 128, 3);
-
-      assertEquals(4096L, SlotLayoutAccessors.readPayloadPointer(slot, layout, 0));
-      assertEquals(128, SlotLayoutAccessors.readPayloadLength(slot, layout, 0));
-      assertEquals(3, SlotLayoutAccessors.readPayloadFlags(slot, layout, 0));
-    }
-  }
-
-  @Test
-  void missingFieldAccessFailsFast() {
-    final NodeKindLayout layout = NodeKindLayouts.layoutFor(NodeKind.NULL_VALUE);
-    try (Arena arena = Arena.ofConfined()) {
-      final MemorySegment slot = arena.allocate(layout.fixedSlotSizeInBytes());
-      assertThrows(IllegalArgumentException.class,
-          () -> SlotLayoutAccessors.readLongField(slot, layout, StructuralField.FIRST_CHILD_KEY));
-    }
-  }
-
-  @Test
-  void invalidPayloadIndexFailsFast() {
-    final NodeKindLayout layout = NodeKindLayouts.layoutFor(NodeKind.STRING_VALUE);
-    try (Arena arena = Arena.ofConfined()) {
-      final MemorySegment slot = arena.allocate(layout.fixedSlotSizeInBytes());
-      assertThrows(IllegalArgumentException.class, () -> SlotLayoutAccessors.readPayloadPointer(slot, layout, 1));
-    }
-  }
-
-  @Test
-  void payloadRefRejectsNegativeLengthOrFlags() {
-    final NodeKindLayout layout = NodeKindLayouts.layoutFor(NodeKind.STRING_VALUE);
-    try (Arena arena = Arena.ofConfined()) {
-      final MemorySegment slot = arena.allocate(layout.fixedSlotSizeInBytes());
-      assertThrows(IllegalArgumentException.class,
-          () -> SlotLayoutAccessors.writePayloadRef(slot, layout, 0, 1L, -1, 0));
-      assertThrows(IllegalArgumentException.class,
-          () -> SlotLayoutAccessors.writePayloadRef(slot, layout, 0, 1L, 1, -1));
-    }
-  }
-}
diff --git a/bundles/sirix-core/src/test/java/io/sirix/page/KeyValueLeafTest.java b/bundles/sirix-core/src/test/java/io/sirix/page/KeyValueLeafTest.java
index 7d2b2b809..64a8d8c5f 100644
--- a/bundles/sirix-core/src/test/java/io/sirix/page/KeyValueLeafTest.java
+++ b/bundles/sirix-core/src/test/java/io/sirix/page/KeyValueLeafTest.java
@@ -2,7 +2,6 @@
 
 import io.sirix.access.ResourceConfiguration;
 import io.sirix.index.IndexType;
-import io.sirix.node.NodeKind;
 import io.sirix.node.json.BooleanNode;
 import io.sirix.settings.Constants;
 import net.openhft.hashing.LongHashFunction;
@@ -13,7 +12,6 @@
 import java.lang.foreign.Arena;
 import java.lang.foreign.MemorySegment;
 import java.lang.foreign.ValueLayout;
-import java.util.Arrays;
 
 import static io.sirix.cache.LinuxMemorySegmentAllocator.SIXTYFOUR_KB;
 import static org.junit.jupiter.api.Assertions.*;
@@ -322,126 +320,6 @@ void testSetSlotMemorySegmentResizing() {
     assertEquals(largeData.byteSize(), slot.byteSize());
   }
 
-  @Test
-  void testHasEnoughSpaceWithSufficientSpace() {
-    // Simulate a situation where there is enough space for the new data.
-    byte[] recordData = new byte[50];
-    int[] offsets = new int[5];
-    Arrays.fill(offsets, -1); // Initially, no slots are occupied.
-
-    try (Arena arena = Arena.ofConfined()) {
-      MemorySegment memory = arena.allocate(200); // Create a memory segment of 200 bytes.
-
-      // Set some initial data.
-      keyValueLeafPage.setSlotMemory(memory);
-      keyValueLeafPage.setSlot(recordData, 0);
-      assertTrue(keyValueLeafPage.hasEnoughSpace(offsets, memory, 50),
-          "There should be enough space for the new data.");
-    }
-  }
-
-  @Test
-  void testHasEnoughSpaceWithExactSpace() {
-    // Simulate a situation where there is exactly enough space.
-    byte[] recordData = new byte[50];
-    int[] offsets = new int[5];
-    Arrays.fill(offsets, -1); // Initially, no slots are occupied.
-
-    try (Arena arena = Arena.ofConfined()) {
-      MemorySegment memory = arena.allocate(106); // Create a memory segment of 106 bytes (100 + 4(size) + 2(aligned).
-
-      // Set some initial data.
-      keyValueLeafPage.setSlotMemory(memory);
-      keyValueLeafPage.setSlot(recordData, 0);
-
-      // Check that there's exactly enough space left.
-      assertTrue(keyValueLeafPage.hasEnoughSpace(offsets, memory, 50),
-          "There should be exactly enough space for the new data.");
-    }
-  }
-
-  @Test
-  void testHasEnoughSpaceWithInsufficientSpace() {
-    // Simulate a situation where there is not enough space for the new data.
-    byte[] recordData = new byte[50];
-    int[] offsets = new int[5];
-    Arrays.fill(offsets, -1); // Initially, no slots are occupied.
-
-    try (Arena arena = Arena.ofConfined()) {
-      MemorySegment memory = arena.allocate(80); // Create a memory segment of 80 bytes.
-
-      // Set some initial data.
-      keyValueLeafPage.setSlotMemory(memory);
-      keyValueLeafPage.setSlot(recordData, 0);
-
-      // Check that there's not enough space for new data.
-      assertFalse(keyValueLeafPage.hasEnoughSpace(offsets, memory, 100),
-          "There should not be enough space for the new data.");
-    }
-  }
-
-  @Test
-  void testHasEnoughSpaceWithLargeOffset() {
-    // Simulate a situation with large offset values and small memory.
-    byte[] recordData = new byte[20];
-    int[] offsets = new int[] {0, 24, -1};
-
-    try (Arena arena = Arena.ofConfined()) {
-      MemorySegment memory = arena.allocate(50); // Small memory segment.
-
-      keyValueLeafPage.setSlotMemory(memory);
-
-      // Set some initial data.
-      keyValueLeafPage.setSlot(recordData, 0);
-      keyValueLeafPage.setSlot(recordData, 1);
-
-      // Check that there's not enough space.
-      assertFalse(keyValueLeafPage.hasEnoughSpace(offsets, memory, 50),
-          "There should not be enough space due to the small memory segment and large offsets.");
-    }
-  }
-
-  @Test
-  void testHasEnoughSpaceWithEmptyMemory() {
-    // Simulate a situation with an empty memory segment.
-    int[] offsets = new int[5];
-    Arrays.fill(offsets, -1); // Initially, no slots are occupied.
-
-    try (Arena arena = Arena.ofConfined()) {
-      MemorySegment memory = arena.allocate(0); // Empty memory segment.
-
-      keyValueLeafPage.setSlotMemory(memory);
-      // Check that there's not enough space.
-      assertFalse(keyValueLeafPage.hasEnoughSpace(offsets, memory, 1),
-          "There should not be enough space with an empty memory segment.");
-    }
-  }
-
-  @Test
-  void testHasEnoughSpaceAfterResizing() {
-    // Simulate a situation where the memory is resized.
-    byte[] recordData = new byte[50];
-    int[] offsets = new int[5];
-    Arrays.fill(offsets, -1); // Initially, no slots are occupied.
-
-    try (Arena arena = Arena.ofConfined()) {
-      MemorySegment memory = arena.allocate(54); // Small memory segment.
-
-      // Set some initial data.
-      keyValueLeafPage.setSlotMemory(memory);
-      keyValueLeafPage.setSlot(recordData, 0);
-
-      // Resize the memory segment.
-      MemorySegment resizedMemory = arena.allocate(100);
-
-      keyValueLeafPage.setSlotMemory(resizedMemory);
-
-      // Check that there's enough space after resizing.
-      assertTrue(keyValueLeafPage.hasEnoughSpace(offsets, resizedMemory, 50),
-          "There should be enough space after resizing the memory segment.");
-    }
-  }
-
   @Test
   void testAddReferencesCopiesOnlyMarkedPreservationSlots() {
     byte[] preserved = new byte[] {42, 43, 44};
@@ -530,7 +408,7 @@ void testAddReferencesCopiesPreservedSlotData() {
   }
 
   @Test
-  void testSetRecordDefersSlotMaterializationUntilAddReferences() {
+  void testSetRecordDefersSerializationForNonSingletonFlyweight() {
     final long nodeKey = 1L;
     final int offset =
         (int) (nodeKey - ((nodeKey >> Constants.NDP_NODE_COUNT_EXPONENT) << Constants.NDP_NODE_COUNT_EXPONENT));
@@ -539,11 +417,9 @@ void testSetRecordDefersSlotMaterializationUntilAddReferences() {
 
     keyValueLeafPage.setRecord(node);
 
+    // Non-singleton FlyweightNode: stored in records[] for processEntries serialization.
+    // Only write singletons are serialized directly to heap.
     assertSame(node, keyValueLeafPage.getRecord(offset));
-    assertNull(keyValueLeafPage.getSlot(offset));
-
-    keyValueLeafPage.addReferences(new ResourceConfiguration.Builder("testResource").build());
-    assertNotNull(keyValueLeafPage.getSlot(offset));
   }
 
   @Test
@@ -564,35 +440,4 @@ void testRawSlotWriteWithoutMaterializedRecord() {
     assertArrayEquals(new byte[] {1, 2, 3}, slot.toArray(ValueLayout.JAVA_BYTE));
   }
 
-  @Test
-  void testFixedSlotFormatMarkersRoundTrip() {
-    final int slot = 13;
-    keyValueLeafPage.setSlot(new byte[] {7, 8, 9}, slot);
-
-    assertFalse(keyValueLeafPage.isFixedSlotFormat(slot));
-    assertNull(keyValueLeafPage.getFixedSlotNodeKind(slot));
-
-    keyValueLeafPage.markSlotAsFixedFormat(slot, NodeKind.BOOLEAN_VALUE);
-    assertTrue(keyValueLeafPage.isFixedSlotFormat(slot));
-    assertEquals(NodeKind.BOOLEAN_VALUE, keyValueLeafPage.getFixedSlotNodeKind(slot));
-
-    keyValueLeafPage.markSlotAsCompactFormat(slot);
-    assertFalse(keyValueLeafPage.isFixedSlotFormat(slot));
-    assertNull(keyValueLeafPage.getFixedSlotNodeKind(slot));
-  }
-
-  @Test
-  void testResetClearsFixedSlotFormatMetadata() {
-    final int slot = 17;
-    keyValueLeafPage.setSlot(new byte[] {1, 2}, slot);
-    keyValueLeafPage.markSlotAsFixedFormat(slot, NodeKind.OBJECT);
-
-    assertTrue(keyValueLeafPage.isFixedSlotFormat(slot));
-    assertEquals(NodeKind.OBJECT, keyValueLeafPage.getFixedSlotNodeKind(slot));
-
-    keyValueLeafPage.reset();
-
-    assertFalse(keyValueLeafPage.isFixedSlotFormat(slot));
-    assertNull(keyValueLeafPage.getFixedSlotNodeKind(slot));
-  }
 }
diff --git a/bundles/sirix-core/src/test/java/io/sirix/page/ResizeFieldCorrectnessTest.java b/bundles/sirix-core/src/test/java/io/sirix/page/ResizeFieldCorrectnessTest.java
new file mode 100644
index 000000000..a197efdf3
--- /dev/null
+++ b/bundles/sirix-core/src/test/java/io/sirix/page/ResizeFieldCorrectnessTest.java
@@ -0,0 +1,422 @@
+package io.sirix.page;
+
+import io.sirix.access.ResourceConfiguration;
+import io.sirix.index.IndexType;
+import io.sirix.node.DeltaVarIntCodec;
+import io.sirix.node.json.ObjectNode;
+import io.sirix.settings.Fixed;
+import net.openhft.hashing.LongHashFunction;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
+import java.lang.foreign.Arena;
+import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
+import java.util.stream.Stream;
+
+import static io.sirix.cache.LinuxMemorySegmentAllocator.SIXTYFOUR_KB;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ * Tests for {@link DeltaVarIntCodec#resizeField} and {@link KeyValueLeafPage#resizeRecordField}.
+ *
+ * 
Verifies INV-4 (offset table consistency) and INV-5 (raw-copy resize correctness)
+ * from the LeanStore write path plan.
+ */
+class ResizeFieldCorrectnessTest {
+
+  private static final long NODE_KEY = 1000L;
+  private static final long PARENT_KEY = 999L;
+  private static final long RIGHT_SIB_KEY = 1001L;
+  private static final long LEFT_SIB_KEY = Fixed.NULL_NODE_KEY.getStandardProperty();
+  private static final long FIRST_CHILD_KEY = 1002L;
+  private static final long LAST_CHILD_KEY = 1005L;
+  private static final int PREV_REVISION = 0;
+  private static final int LAST_MOD_REVISION = 1;
+  private static final long HASH = 0xDEADBEEFCAFEL;
+  private static final long CHILD_COUNT = 4L;
+  private static final long DESCENDANT_COUNT = 42L;
+
+  private KeyValueLeafPage page;
+  private Arena arena;
+  private ObjectNode objectNode;
+
+  @BeforeEach
+  void setUp() {
+    arena = Arena.ofConfined();
+    page = new KeyValueLeafPage(0L, IndexType.DOCUMENT,
+        new ResourceConfiguration.Builder("testResource").build(), 1,
+        arena.allocate(SIXTYFOUR_KB), null);
+
+    objectNode = new ObjectNode(NODE_KEY, PARENT_KEY, PREV_REVISION, LAST_MOD_REVISION,
+        RIGHT_SIB_KEY, LEFT_SIB_KEY, FIRST_CHILD_KEY, LAST_CHILD_KEY,
+        CHILD_COUNT, DESCENDANT_COUNT, HASH,
+        LongHashFunction.xx3(), (byte[]) null);
+    objectNode.setWriteSingleton(true);
+  }
+
+  @AfterEach
+  void tearDown() {
+    if (page != null) {
+      page.close();
+    }
+    if (arena != null) {
+      arena.close();
+    }
+  }
+
+  /**
+   * Helper: serialize ObjectNode to the page heap at slot 0, then bind it.
+   */
+  private void serializeAndBind() {
+    page.serializeNewRecord(objectNode, NODE_KEY, 0);
+    // serializeNewRecord calls clearBinding, so re-bind manually
+    final MemorySegment sp = page.getSlottedPage();
+    final int heapOff = PageLayout.getDirHeapOffset(sp, 0);
+    final long recordBase = PageLayout.heapAbsoluteOffset(heapOff);
+    objectNode.bind(sp, recordBase, NODE_KEY, 0);
+    objectNode.setOwnerPage(page);
+  }
+
+  /**
+   * Verify all 10 fields of the bound ObjectNode match expected values.
+   */
+  private void assertAllFields(final long expectedParent, final long expectedRightSib,
+      final long expectedLeftSib, final long expectedFirstChild, final long expectedLastChild,
+      final int expectedPrevRev, final int expectedLastModRev, final long expectedHash,
+      final long expectedChildCount, final long expectedDescCount) {
+    assertEquals(expectedParent, objectNode.getParentKey(), "parentKey");
+    assertEquals(expectedRightSib, objectNode.getRightSiblingKey(), "rightSiblingKey");
+    assertEquals(expectedLeftSib, objectNode.getLeftSiblingKey(), "leftSiblingKey");
+    assertEquals(expectedFirstChild, objectNode.getFirstChildKey(), "firstChildKey");
+    assertEquals(expectedLastChild, objectNode.getLastChildKey(), "lastChildKey");
+    assertEquals(expectedPrevRev, objectNode.getPreviousRevisionNumber(), "previousRevision");
+    assertEquals(expectedLastModRev, objectNode.getLastModifiedRevisionNumber(), "lastModifiedRevision");
+    assertEquals(expectedHash, objectNode.getHash(), "hash");
+    assertEquals(expectedChildCount, objectNode.getChildCount(), "childCount");
+    assertEquals(expectedDescCount, objectNode.getDescendantCount(), "descendantCount");
+  }
+
+  // ==================== INV-5: Raw-Copy Resize Correctness ====================
+
+  /**
+   * Provides (fieldIndex, newValue) pairs for each of the 10 ObjectNode fields.
+   * Each new value is chosen to require a different varint width than the original.
+   */
+  static Stream fieldResizeParameters() {
+    // Original values produce small deltas (1-2 byte varints).
+    // New values produce large deltas (3+ byte varints) to force width change.
+    final long farKey = NODE_KEY + 100_000L; // large delta → 3-byte varint
+    return Stream.of(
+        // fieldIndex, newValue (key or int/long), description
+        Arguments.of(NodeFieldLayout.OBJECT_PARENT_KEY, farKey, "parentKey"),
+        Arguments.of(NodeFieldLayout.OBJECT_RIGHT_SIB_KEY, farKey, "rightSiblingKey"),
+        Arguments.of(NodeFieldLayout.OBJECT_LEFT_SIB_KEY, farKey, "leftSiblingKey"),
+        Arguments.of(NodeFieldLayout.OBJECT_FIRST_CHILD_KEY, farKey, "firstChildKey"),
+        Arguments.of(NodeFieldLayout.OBJECT_LAST_CHILD_KEY, farKey, "lastChildKey"),
+        // Revision fields: small → large signed varint
+        Arguments.of(NodeFieldLayout.OBJECT_PREV_REVISION, 100_000L, "previousRevision"),
+        Arguments.of(NodeFieldLayout.OBJECT_LAST_MOD_REVISION, 100_000L, "lastModifiedRevision"),
+        // Hash: fixed 8 bytes, no width change — test that it survives resize of OTHER field
+        // childCount/descendantCount: signed long varint
+        Arguments.of(NodeFieldLayout.OBJECT_CHILD_COUNT, 100_000L, "childCount"),
+        Arguments.of(NodeFieldLayout.OBJECT_DESCENDANT_COUNT, 100_000L, "descendantCount")
+    );
+  }
+
+  @ParameterizedTest(name = "resize field {2} (index={0})")
+  @MethodSource("fieldResizeParameters")
+  void resizeRecordField_preservesUnchangedFields(final int fieldIndex, final long newValue,
+      final String fieldName) {
+    serializeAndBind();
+
+    // Record heap state before resize
+    final MemorySegment sp = page.getSlottedPage();
+    final int heapEndBefore = PageLayout.getHeapEnd(sp);
+
+    // Perform raw-copy resize via KVL
+    final DeltaVarIntCodec.FieldEncoder encoder = createEncoder(fieldIndex, newValue);
+    page.resizeRecordField(objectNode, NODE_KEY, 0, fieldIndex,
+        NodeFieldLayout.OBJECT_FIELD_COUNT, encoder);
+
+    // INV-2: Heap monotonicity
+    final int heapEndAfter = PageLayout.getHeapEnd(page.getSlottedPage());
+    assertTrue(heapEndAfter > heapEndBefore, "heapEnd must advance after resize");
+
+    // INV-5: All unchanged fields preserved, changed field updated
+    final long expectedParent = fieldIndex == NodeFieldLayout.OBJECT_PARENT_KEY ? newValue : PARENT_KEY;
+    final long expectedRightSib = fieldIndex == NodeFieldLayout.OBJECT_RIGHT_SIB_KEY ? newValue : RIGHT_SIB_KEY;
+    final long expectedLeftSib = fieldIndex == NodeFieldLayout.OBJECT_LEFT_SIB_KEY ? newValue : LEFT_SIB_KEY;
+    final long expectedFirstChild = fieldIndex == NodeFieldLayout.OBJECT_FIRST_CHILD_KEY ? newValue : FIRST_CHILD_KEY;
+    final long expectedLastChild = fieldIndex == NodeFieldLayout.OBJECT_LAST_CHILD_KEY ? newValue : LAST_CHILD_KEY;
+    final int expectedPrevRev = fieldIndex == NodeFieldLayout.OBJECT_PREV_REVISION ? (int) newValue : PREV_REVISION;
+    final int expectedLastModRev = fieldIndex == NodeFieldLayout.OBJECT_LAST_MOD_REVISION ? (int) newValue : LAST_MOD_REVISION;
+    final long expectedChildCount = fieldIndex == NodeFieldLayout.OBJECT_CHILD_COUNT ? newValue : CHILD_COUNT;
+    final long expectedDescCount = fieldIndex == NodeFieldLayout.OBJECT_DESCENDANT_COUNT ? newValue : DESCENDANT_COUNT;
+
+    assertAllFields(expectedParent, expectedRightSib, expectedLeftSib,
+        expectedFirstChild, expectedLastChild,
+        expectedPrevRev, expectedLastModRev,
+        HASH, // hash is always fixed 8 bytes, never changed in this test
+        expectedChildCount, expectedDescCount);
+  }
+
+  /**
+   * Test resizing a field that shrinks (large varint → small varint).
+   * This exercises the negative widthDelta path.
+   */
+  @Test
+  void resizeRecordField_shrinkField() {
+    // Create node with a far-away parent (large delta → multi-byte varint)
+    final long farParent = NODE_KEY + 100_000L;
+    objectNode = new ObjectNode(NODE_KEY, farParent, PREV_REVISION, LAST_MOD_REVISION,
+        RIGHT_SIB_KEY, LEFT_SIB_KEY, FIRST_CHILD_KEY, LAST_CHILD_KEY,
+        CHILD_COUNT, DESCENDANT_COUNT, HASH,
+        LongHashFunction.xx3(), (byte[]) null);
+    objectNode.setWriteSingleton(true);
+    serializeAndBind();
+
+    // Now resize parentKey back to a nearby value (small delta → 1-byte varint)
+    final long nearParent = NODE_KEY - 1;
+    final DeltaVarIntCodec.FieldEncoder encoder = (target, offset) ->
+        DeltaVarIntCodec.writeDeltaToSegment(target, offset, nearParent, NODE_KEY);
+    page.resizeRecordField(objectNode, NODE_KEY, 0, NodeFieldLayout.OBJECT_PARENT_KEY,
+        NodeFieldLayout.OBJECT_FIELD_COUNT, encoder);
+
+    assertAllFields(nearParent, RIGHT_SIB_KEY, LEFT_SIB_KEY,
+        FIRST_CHILD_KEY, LAST_CHILD_KEY,
+        PREV_REVISION, LAST_MOD_REVISION, HASH,
+        CHILD_COUNT, DESCENDANT_COUNT);
+  }
+
+  /**
+   * Test resizing NULL_NODE_KEY field to a real value and back.
+   */
+  @Test
+  void resizeRecordField_nullToReal_and_realToNull() {
+    serializeAndBind();
+
+    // leftSiblingKey starts as NULL (-1). Resize to a real value.
+    final long realSib = NODE_KEY + 50_000L;
+    DeltaVarIntCodec.FieldEncoder encoder = (target, offset) ->
+        DeltaVarIntCodec.writeDeltaToSegment(target, offset, realSib, NODE_KEY);
+    page.resizeRecordField(objectNode, NODE_KEY, 0, NodeFieldLayout.OBJECT_LEFT_SIB_KEY,
+        NodeFieldLayout.OBJECT_FIELD_COUNT, encoder);
+
+    assertEquals(realSib, objectNode.getLeftSiblingKey());
+    // Other fields preserved
+    assertEquals(PARENT_KEY, objectNode.getParentKey());
+    assertEquals(HASH, objectNode.getHash());
+
+    // Now resize back to NULL
+    final long nullKey = Fixed.NULL_NODE_KEY.getStandardProperty();
+    encoder = (target, offset) ->
+        DeltaVarIntCodec.writeDeltaToSegment(target, offset, nullKey, NODE_KEY);
+    page.resizeRecordField(objectNode, NODE_KEY, 0, NodeFieldLayout.OBJECT_LEFT_SIB_KEY,
+        NodeFieldLayout.OBJECT_FIELD_COUNT, encoder);
+
+    assertEquals(nullKey, objectNode.getLeftSiblingKey());
+    assertEquals(PARENT_KEY, objectNode.getParentKey());
+    assertEquals(HASH, objectNode.getHash());
+  }
+
+  /**
+   * Test multiple consecutive resizes on the same node (fragmentation test).
+   * INV-2: heap must grow monotonically. INV-8: fragmentation tracked.
+   */
+  @Test
+  void resizeRecordField_multipleResizes_heapMonotonic() {
+    serializeAndBind();
+
+    final MemorySegment sp = page.getSlottedPage();
+    int prevHeapEnd = PageLayout.getHeapEnd(sp);
+
+    // Resize 5 different fields consecutively
+    final long farKey = NODE_KEY + 200_000L;
+    final int[] fields = {
+        NodeFieldLayout.OBJECT_PARENT_KEY,
+        NodeFieldLayout.OBJECT_RIGHT_SIB_KEY,
+        NodeFieldLayout.OBJECT_FIRST_CHILD_KEY,
+        NodeFieldLayout.OBJECT_CHILD_COUNT,
+        NodeFieldLayout.OBJECT_DESCENDANT_COUNT
+    };
+
+    for (final int field : fields) {
+      final DeltaVarIntCodec.FieldEncoder encoder = createEncoder(field, farKey);
+      page.resizeRecordField(objectNode, NODE_KEY, 0, field,
+          NodeFieldLayout.OBJECT_FIELD_COUNT, encoder);
+
+      final int currentHeapEnd = PageLayout.getHeapEnd(page.getSlottedPage());
+      assertTrue(currentHeapEnd > prevHeapEnd,
+          "heapEnd must advance after resize of field " + field);
+      prevHeapEnd = currentHeapEnd;
+    }
+
+    // Verify all resized fields have the new value
+    assertEquals(farKey, objectNode.getParentKey());
+    assertEquals(farKey, objectNode.getRightSiblingKey());
+    assertEquals(farKey, objectNode.getFirstChildKey());
+    assertEquals(farKey, objectNode.getChildCount());
+    assertEquals(farKey, objectNode.getDescendantCount());
+
+    // Unchanged fields preserved
+    assertEquals(LEFT_SIB_KEY, objectNode.getLeftSiblingKey());
+    assertEquals(LAST_CHILD_KEY, objectNode.getLastChildKey());
+    assertEquals(HASH, objectNode.getHash());
+  }
+
+  // ==================== INV-4: Offset Table Consistency ====================
+
+  @Test
+  void resizeRecordField_offsetTableMonotonic() {
+    serializeAndBind();
+
+    // Resize a middle field to force offset shifts
+    final long farKey = NODE_KEY + 100_000L;
+    final DeltaVarIntCodec.FieldEncoder encoder = (target, offset) ->
+        DeltaVarIntCodec.writeDeltaToSegment(target, offset, farKey, NODE_KEY);
+    page.resizeRecordField(objectNode, NODE_KEY, 0,
+        NodeFieldLayout.OBJECT_FIRST_CHILD_KEY,
+        NodeFieldLayout.OBJECT_FIELD_COUNT, encoder);
+
+    // Read offset table and verify monotonicity
+    final MemorySegment sp = page.getSlottedPage();
+    final int heapOffset = PageLayout.getDirHeapOffset(sp, 0);
+    final long recordBase = PageLayout.heapAbsoluteOffset(heapOffset);
+
+    int prevOffset = -1;
+    for (int i = 0; i < NodeFieldLayout.OBJECT_FIELD_COUNT; i++) {
+      final int fieldOff = sp.get(ValueLayout.JAVA_BYTE, recordBase + 1 + i) & 0xFF;
+      assertTrue(fieldOff > prevOffset || (i == 0 && fieldOff == 0),
+          "offset table must be monotonically increasing: field " + i
+              + " offset=" + fieldOff + " prev=" + prevOffset);
+      prevOffset = fieldOff;
+    }
+  }
+
+  // ==================== INV-3: Directory-Heap Consistency ====================
+
+  @Test
+  void resizeRecordField_directoryPointsWithinHeap() {
+    serializeAndBind();
+
+    // Resize
+    final long farKey = NODE_KEY + 100_000L;
+    final DeltaVarIntCodec.FieldEncoder encoder = (target, offset) ->
+        DeltaVarIntCodec.writeDeltaToSegment(target, offset, farKey, NODE_KEY);
+    page.resizeRecordField(objectNode, NODE_KEY, 0,
+        NodeFieldLayout.OBJECT_PARENT_KEY,
+        NodeFieldLayout.OBJECT_FIELD_COUNT, encoder);
+
+    final MemorySegment sp = page.getSlottedPage();
+    final int dirHeapOff = PageLayout.getDirHeapOffset(sp, 0);
+    final int dirDataLen = PageLayout.getDirDataLength(sp, 0);
+    final int heapEnd = PageLayout.getHeapEnd(sp);
+
+    assertTrue(dirHeapOff + dirDataLen <= heapEnd,
+        "directory entry must point within heap bounds");
+    assertTrue(PageLayout.isSlotPopulated(sp, 0), "slot must remain populated");
+    assertTrue(PageLayout.getDirNodeKindId(sp, 0) > 0, "nodeKindId must be > 0");
+  }
+
+  // ==================== DeltaVarIntCodec.resizeField unit test ====================
+
+  @Test
+  void resizeField_directCodecCall() {
+    // Create a small MemorySegment with a mock record:
+    // [kindByte:1][offsets:3][field0:1byte][field1:1byte][field2:1byte]
+    final int fieldCount = 3;
+    final byte[] src = new byte[64];
+    final MemorySegment srcSeg = MemorySegment.ofArray(src);
+
+    // Write mock record
+    srcSeg.set(ValueLayout.JAVA_BYTE, 0, (byte) 42); // nodeKind
+    // Offset table: field0 at 0, field1 at 2, field2 at 4
+    srcSeg.set(ValueLayout.JAVA_BYTE, 1, (byte) 0);
+    srcSeg.set(ValueLayout.JAVA_BYTE, 2, (byte) 2);
+    srcSeg.set(ValueLayout.JAVA_BYTE, 3, (byte) 4);
+    // Data region starts at offset 4 (1 + 3)
+    // field0: 2 bytes [0xAA, 0xBB]
+    srcSeg.set(ValueLayout.JAVA_BYTE, 4, (byte) 0xAA);
+    srcSeg.set(ValueLayout.JAVA_BYTE, 5, (byte) 0xBB);
+    // field1: 2 bytes [0xCC, 0xDD]
+    srcSeg.set(ValueLayout.JAVA_BYTE, 6, (byte) 0xCC);
+    srcSeg.set(ValueLayout.JAVA_BYTE, 7, (byte) 0xDD);
+    // field2: 2 bytes [0xEE, 0xFF]
+    srcSeg.set(ValueLayout.JAVA_BYTE, 8, (byte) 0xEE);
+    srcSeg.set(ValueLayout.JAVA_BYTE, 9, (byte) 0xFF);
+
+    final int srcRecordLen = 10; // 1 + 3 + 6
+
+    // Resize field1 from 2 bytes to 3 bytes [0x11, 0x22, 0x33]
+    final byte[] dst = new byte[64];
+    final MemorySegment dstSeg = MemorySegment.ofArray(dst);
+
+    final int newRecordLen = DeltaVarIntCodec.resizeField(
+        srcSeg, 0, srcRecordLen,
+        fieldCount, 1,
+        dstSeg, 0,
+        (target, offset) -> {
+          target.set(ValueLayout.JAVA_BYTE, offset, (byte) 0x11);
+          target.set(ValueLayout.JAVA_BYTE, offset + 1, (byte) 0x22);
+          target.set(ValueLayout.JAVA_BYTE, offset + 2, (byte) 0x33);
+          return 3;
+        });
+
+    // Expected: 1 + 3 + (2 + 3 + 2) = 11 bytes
+    assertEquals(11, newRecordLen);
+
+    // NodeKind preserved
+    assertEquals(42, dstSeg.get(ValueLayout.JAVA_BYTE, 0));
+
+    // Offset table: field0=0, field1=2 (unchanged), field2=5 (shifted by +1)
+    assertEquals(0, dstSeg.get(ValueLayout.JAVA_BYTE, 1) & 0xFF);
+    assertEquals(2, dstSeg.get(ValueLayout.JAVA_BYTE, 2) & 0xFF);
+    assertEquals(5, dstSeg.get(ValueLayout.JAVA_BYTE, 3) & 0xFF);
+
+    // Data region at offset 4:
+    // field0: [0xAA, 0xBB] (unchanged)
+    assertEquals((byte) 0xAA, dstSeg.get(ValueLayout.JAVA_BYTE, 4));
+    assertEquals((byte) 0xBB, dstSeg.get(ValueLayout.JAVA_BYTE, 5));
+    // field1: [0x11, 0x22, 0x33] (new value)
+    assertEquals((byte) 0x11, dstSeg.get(ValueLayout.JAVA_BYTE, 6));
+    assertEquals((byte) 0x22, dstSeg.get(ValueLayout.JAVA_BYTE, 7));
+    assertEquals((byte) 0x33, dstSeg.get(ValueLayout.JAVA_BYTE, 8));
+    // field2: [0xEE, 0xFF] (unchanged, shifted)
+    assertEquals((byte) 0xEE, dstSeg.get(ValueLayout.JAVA_BYTE, 9));
+    assertEquals((byte) 0xFF, dstSeg.get(ValueLayout.JAVA_BYTE, 10));
+  }
+
+  // ==================== Helpers ====================
+
+  /**
+   * Create a FieldEncoder for the given ObjectNode field index and new value.
+   */
+  private DeltaVarIntCodec.FieldEncoder createEncoder(final int fieldIndex, final long newValue) {
+    return switch (fieldIndex) {
+      case NodeFieldLayout.OBJECT_PARENT_KEY,
+           NodeFieldLayout.OBJECT_RIGHT_SIB_KEY,
+           NodeFieldLayout.OBJECT_LEFT_SIB_KEY,
+           NodeFieldLayout.OBJECT_FIRST_CHILD_KEY,
+           NodeFieldLayout.OBJECT_LAST_CHILD_KEY ->
+          (target, offset) -> DeltaVarIntCodec.writeDeltaToSegment(target, offset, newValue, NODE_KEY);
+      case NodeFieldLayout.OBJECT_PREV_REVISION,
+           NodeFieldLayout.OBJECT_LAST_MOD_REVISION ->
+          (target, offset) -> DeltaVarIntCodec.writeSignedToSegment(target, offset, (int) newValue);
+      case NodeFieldLayout.OBJECT_HASH ->
+          (target, offset) -> {
+            DeltaVarIntCodec.writeLongToSegment(target, offset, newValue);
+            return Long.BYTES;
+          };
+      case NodeFieldLayout.OBJECT_CHILD_COUNT,
+           NodeFieldLayout.OBJECT_DESCENDANT_COUNT ->
+          (target, offset) -> DeltaVarIntCodec.writeSignedLongToSegment(target, offset, newValue);
+      default -> throw new IllegalArgumentException("Unknown field index: " + fieldIndex);
+    };
+  }
+}
diff --git a/bundles/sirix-core/src/test/java/io/sirix/page/SlotOffsetCodecTest.java b/bundles/sirix-core/src/test/java/io/sirix/page/SlotOffsetCodecTest.java
deleted file mode 100644
index ee5ccc167..000000000
--- a/bundles/sirix-core/src/test/java/io/sirix/page/SlotOffsetCodecTest.java
+++ /dev/null
@@ -1,399 +0,0 @@
-/*
- * Copyright (c) 2023, Sirix Contributors
- *
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *     * Redistributions of source code must retain the above copyright
- *       notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above copyright
- *       notice, this list of conditions and the following disclaimer in the
- *       documentation and/or other materials provided with the distribution.
- *     * Neither the name of the  nor the
- *       names of its contributors may be used to endorse or promote products
- *       derived from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
- * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED. IN NO EVENT SHALL  BE LIABLE FOR ANY
- * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
- * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
- * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
- * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package io.sirix.page;
-
-import io.sirix.node.Bytes;
-import io.sirix.node.BytesIn;
-import io.sirix.node.BytesOut;
-import io.sirix.settings.Constants;
-import org.junit.jupiter.api.Test;
-
-import java.util.Arrays;
-import java.util.Random;
-
-import static org.junit.jupiter.api.Assertions.assertArrayEquals;
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertThrows;
-
-/**
- * Unit tests for {@link SlotOffsetCodec}.
- * 

- * Tests cover: - Empty pages - Single slot - Fully populated pages - Sparse pages - Large offsets
- * (requiring 16+ bits) - Round-trip serialization/deserialization - Bit-packing edge cases
- */
-public final class SlotOffsetCodecTest {
-
-  @Test
-  public void testEmptyPage() {
-    // All slots empty (-1)
-    int[] slotOffsets = new int[Constants.NDP_NODE_COUNT];
-    Arrays.fill(slotOffsets, -1);
-
-    BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    SlotOffsetCodec.encode(sink, slotOffsets, -1);
-
-    BytesIn source = sink.bytesForRead();
-    int[] decoded = SlotOffsetCodec.decode(source);
-
-    assertArrayEquals(slotOffsets, decoded, "Empty page should decode to all -1");
-  }
-
-  @Test
-  public void testSingleSlot() {
-    int[] slotOffsets = new int[Constants.NDP_NODE_COUNT];
-    Arrays.fill(slotOffsets, -1);
-    slotOffsets[0] = 0;
-
-    BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    SlotOffsetCodec.encode(sink, slotOffsets, 0);
-
-    BytesIn source = sink.bytesForRead();
-    int[] decoded = SlotOffsetCodec.decode(source);
-
-    assertArrayEquals(slotOffsets, decoded, "Single slot at index 0 should round-trip correctly");
-  }
-
-  @Test
-  public void testSingleSlotMiddle() {
-    int[] slotOffsets = new int[Constants.NDP_NODE_COUNT];
-    Arrays.fill(slotOffsets, -1);
-    slotOffsets[512] = 1000;
-
-    BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    SlotOffsetCodec.encode(sink, slotOffsets, 512);
-
-    BytesIn source = sink.bytesForRead();
-    int[] decoded = SlotOffsetCodec.decode(source);
-
-    assertArrayEquals(slotOffsets, decoded, "Single slot in middle should round-trip correctly");
-  }
-
-  @Test
-  public void testFullyPopulated() {
-    int[] slotOffsets = new int[Constants.NDP_NODE_COUNT];
-    int offset = 0;
-    for (int i = 0; i < Constants.NDP_NODE_COUNT; i++) {
-      slotOffsets[i] = offset;
-      offset += 50; // Each record ~50 bytes
-    }
-
-    BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    SlotOffsetCodec.encode(sink, slotOffsets, Constants.NDP_NODE_COUNT - 1);
-
-    long compressedSize = sink.writePosition();
-
-    BytesIn source = sink.bytesForRead();
-    int[] decoded = SlotOffsetCodec.decode(source);
-
-    assertArrayEquals(slotOffsets, decoded, "Fully populated page should round-trip correctly");
-
-    // Verify compression - should be much smaller than 4096 bytes
-    int rawSize = Constants.NDP_NODE_COUNT * 4; // 4096 bytes
-    System.out.printf("Full page compression: raw=%d, compressed=%d, ratio=%.1f%%%n", rawSize, compressedSize,
-        (100.0 * compressedSize / rawSize));
-  }
-
-  @Test
-  public void testSparsePageRandom() {
-    Random random = new Random(42); // Fixed seed for reproducibility
-    int[] slotOffsets = new int[Constants.NDP_NODE_COUNT];
-    Arrays.fill(slotOffsets, -1);
-
-    // Populate ~10% of slots
-    int offset = 0;
-    int lastSlot = -1;
-    for (int i = 0; i < Constants.NDP_NODE_COUNT; i++) {
-      if (random.nextDouble() < 0.1) {
-        slotOffsets[i] = offset;
-        offset += random.nextInt(100) + 10;
-        lastSlot = i;
-      }
-    }
-
-    BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    SlotOffsetCodec.encode(sink, slotOffsets, lastSlot);
-
-    long compressedSize = sink.writePosition();
-
-    BytesIn source = sink.bytesForRead();
-    int[] decoded = SlotOffsetCodec.decode(source);
-
-    assertArrayEquals(slotOffsets, decoded, "Sparse page should round-trip correctly");
-
-    int rawSize = Constants.NDP_NODE_COUNT * 4;
-    System.out.printf("Sparse page compression: raw=%d, compressed=%d, ratio=%.1f%%%n", rawSize, compressedSize,
-        (100.0 * compressedSize / rawSize));
-  }
-
-  @Test
-  public void testLargeOffsets() {
-    // Test with offsets requiring 16+ bits
-    int[] slotOffsets = new int[Constants.NDP_NODE_COUNT];
-    Arrays.fill(slotOffsets, -1);
-
-    slotOffsets[0] = 0;
-    slotOffsets[1] = 65536; // 2^16
-    slotOffsets[2] = 131072; // 2^17
-    slotOffsets[3] = 200000;
-
-    BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    SlotOffsetCodec.encode(sink, slotOffsets, 3);
-
-    BytesIn source = sink.bytesForRead();
-    int[] decoded = SlotOffsetCodec.decode(source);
-
-    assertArrayEquals(slotOffsets, decoded, "Large offsets should round-trip correctly");
-  }
-
-  @Test
-  public void testMaxIntOffsets() {
-    // Test with maximum integer offsets
-    int[] slotOffsets = new int[Constants.NDP_NODE_COUNT];
-    Arrays.fill(slotOffsets, -1);
-
-    slotOffsets[0] = 0;
-    slotOffsets[1] = Integer.MAX_VALUE / 2;
-    slotOffsets[2] = Integer.MAX_VALUE;
-
-    BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    SlotOffsetCodec.encode(sink, slotOffsets, 2);
-
-    BytesIn source = sink.bytesForRead();
-    int[] decoded = SlotOffsetCodec.decode(source);
-
-    assertArrayEquals(slotOffsets, decoded, "Max int offsets should round-trip correctly");
-  }
-
-  @Test
-  public void testConsecutiveSlots() {
-    // Slots 0-99 with sequential offsets
-    int[] slotOffsets = new int[Constants.NDP_NODE_COUNT];
-    Arrays.fill(slotOffsets, -1);
-
-    for (int i = 0; i < 100; i++) {
-      slotOffsets[i] = i * 32;
-    }
-
-    BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    SlotOffsetCodec.encode(sink, slotOffsets, 99);
-
-    BytesIn source = sink.bytesForRead();
-    int[] decoded = SlotOffsetCodec.decode(source);
-
-    assertArrayEquals(slotOffsets, decoded, "Consecutive slots should round-trip correctly");
-  }
-
-  @Test
-  public void testOffsetsWithGaps() {
-    // Test offsets with varying gaps between them (all still monotonic)
-    int[] slotOffsets = new int[Constants.NDP_NODE_COUNT];
-    Arrays.fill(slotOffsets, -1);
-
-    // Offsets with varying gaps
-    slotOffsets[0] = 0;
-    slotOffsets[1] = 10; // Small gap
-    slotOffsets[2] = 1000; // Large gap
-    slotOffsets[3] = 1001; // Tiny gap
-
-    BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    SlotOffsetCodec.encode(sink, slotOffsets, 3);
-
-    BytesIn source = sink.bytesForRead();
-    int[] decoded = SlotOffsetCodec.decode(source);
-
-    assertArrayEquals(slotOffsets, decoded, "Varying gap offsets should round-trip");
-  }
-
-  @Test
-  public void testBitPackingWithVariousBitWidths() {
-    // Test bit widths that are commonly used (1-16 bits covers typical offset deltas)
-    int[] bitWidths = {1, 2, 3, 4, 5, 7, 8, 15, 16};
-
-    for (int bitWidth : bitWidths) {
-      // Create values that require exactly bitWidth bits
-      int maxValue = (1 << bitWidth) - 1;
-      int[] values = new int[100];
-      Random random = new Random(bitWidth);
-      for (int i = 0; i < values.length; i++) {
-        values[i] = random.nextInt(maxValue + 1);
-      }
-
-      BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-      SlotOffsetCodec.writeBitPacked(sink, values, bitWidth);
-
-      BytesIn source = sink.bytesForRead();
-      int[] decoded = SlotOffsetCodec.readBitPacked(source, values.length, bitWidth);
-
-      assertArrayEquals(values, decoded, "Bit-packing with " + bitWidth + " bits should round-trip correctly");
-    }
-  }
-
-  @Test
-  public void testBitPackingWith32Bits() {
-    // Special test for 32-bit values which need careful handling
-    int[] values = {0, 1, Integer.MAX_VALUE / 2, Integer.MAX_VALUE - 1, Integer.MAX_VALUE};
-
-    BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    SlotOffsetCodec.writeBitPacked(sink, values, 32);
-
-    BytesIn source = sink.bytesForRead();
-    int[] decoded = SlotOffsetCodec.readBitPacked(source, values.length, 32);
-
-    assertArrayEquals(values, decoded, "32-bit packing should round-trip correctly");
-  }
-
-  @Test
-  public void testBitPackingEdgeCaseZeroValues() {
-    int[] values = new int[100];
-    Arrays.fill(values, 0);
-
-    BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    SlotOffsetCodec.writeBitPacked(sink, values, 1);
-
-    BytesIn source = sink.bytesForRead();
-    int[] decoded = SlotOffsetCodec.readBitPacked(source, values.length, 1);
-
-    assertArrayEquals(values, decoded, "All-zero values should round-trip");
-  }
-
-  @Test
-  public void testBitPackingEmptyArray() {
-    int[] values = new int[0];
-
-    BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    SlotOffsetCodec.writeBitPacked(sink, values, 8);
-
-    BytesIn source = sink.bytesForRead();
-    int[] decoded = SlotOffsetCodec.readBitPacked(source, 0, 8);
-
-    assertArrayEquals(values, decoded, "Empty array should round-trip");
-  }
-
-  @Test
-  public void testCompressionRatioRealistic() {
-    // Simulate realistic page with varying record sizes
-    Random random = new Random(12345);
-    int[] slotOffsets = new int[Constants.NDP_NODE_COUNT];
-    Arrays.fill(slotOffsets, -1);
-
-    int offset = 0;
-    int lastSlot = -1;
-
-    // Populate 80% of slots with realistic record sizes (30-200 bytes)
-    for (int i = 0; i < Constants.NDP_NODE_COUNT; i++) {
-      if (random.nextDouble() < 0.8) {
-        slotOffsets[i] = offset;
-        offset += 30 + random.nextInt(170); // 30-200 byte records
-        lastSlot = i;
-      }
-    }
-
-    BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    SlotOffsetCodec.encode(sink, slotOffsets, lastSlot);
-
-    long compressedSize = sink.writePosition();
-    int rawSize = Constants.NDP_NODE_COUNT * 4;
-
-    BytesIn source = sink.bytesForRead();
-    int[] decoded = SlotOffsetCodec.decode(source);
-
-    assertArrayEquals(slotOffsets, decoded, "Realistic page should round-trip correctly");
-
-    double ratio = (100.0 * compressedSize / rawSize);
-    System.out.printf("Realistic page (80%% full): raw=%d, compressed=%d, ratio=%.1f%%, savings=%.1f%%%n", rawSize,
-        compressedSize, ratio, 100 - ratio);
-
-    // Expect at least 50% compression
-    assert compressedSize < rawSize * 0.5 : "Expected at least 50% compression but got " + ratio + "%";
-  }
-
-  @Test
-  public void testNullSinkThrows() {
-    int[] slotOffsets = new int[Constants.NDP_NODE_COUNT];
-    assertThrows(NullPointerException.class, () -> SlotOffsetCodec.encode(null, slotOffsets, -1));
-  }
-
-  @Test
-  public void testNullOffsetsThrows() {
-    BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    assertThrows(NullPointerException.class, () -> SlotOffsetCodec.encode(sink, null, -1));
-  }
-
-  @Test
-  public void testWrongArrayLengthThrows() {
-    BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    int[] wrongSize = new int[100]; // Not 1024
-    assertThrows(IllegalArgumentException.class, () -> SlotOffsetCodec.encode(sink, wrongSize, -1));
-  }
-
-  @Test
-  public void testNullSourceThrows() {
-    assertThrows(NullPointerException.class, () -> SlotOffsetCodec.decode(null));
-  }
-
-  @Test
-  public void testFirstSlotOnly() {
-    // Edge case: only slot 0 is populated
-    int[] slotOffsets = new int[Constants.NDP_NODE_COUNT];
-    Arrays.fill(slotOffsets, -1);
-    slotOffsets[0] = 0;
-
-    BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    SlotOffsetCodec.encode(sink, slotOffsets, 0);
-
-    BytesIn source = sink.bytesForRead();
-    int[] decoded = SlotOffsetCodec.decode(source);
-
-    assertEquals(0, decoded[0]);
-    for (int i = 1; i < Constants.NDP_NODE_COUNT; i++) {
-      assertEquals(-1, decoded[i], "Slot " + i + " should be -1");
-    }
-  }
-
-  @Test
-  public void testLastSlotOnly() {
-    // Edge case: only the last slot is populated
-    int[] slotOffsets = new int[Constants.NDP_NODE_COUNT];
-    Arrays.fill(slotOffsets, -1);
-    slotOffsets[Constants.NDP_NODE_COUNT - 1] = 65535;
-
-    BytesOut sink = Bytes.elasticOffHeapByteBuffer();
-    SlotOffsetCodec.encode(sink, slotOffsets, Constants.NDP_NODE_COUNT - 1);
-
-    BytesIn source = sink.bytesForRead();
-    int[] decoded = SlotOffsetCodec.decode(source);
-
-    for (int i = 0; i < Constants.NDP_NODE_COUNT - 1; i++) {
-      assertEquals(-1, decoded[i], "Slot " + i + " should be -1");
-    }
-    assertEquals(65535, decoded[Constants.NDP_NODE_COUNT - 1]);
-  }
-}
-
-
diff --git a/bundles/sirix-core/src/test/java/io/sirix/service/json/shredder/JsonShredderTest.java b/bundles/sirix-core/src/test/java/io/sirix/service/json/shredder/JsonShredderTest.java
index cdb2b7b01..c8c223fc5 100644
--- a/bundles/sirix-core/src/test/java/io/sirix/service/json/shredder/JsonShredderTest.java
+++ b/bundles/sirix-core/src/test/java/io/sirix/service/json/shredder/JsonShredderTest.java
@@ -10,6 +10,7 @@
 import io.sirix.api.Axis;
 import io.sirix.api.Database;
 import io.sirix.api.json.JsonResourceSession;
+import io.sirix.settings.Fixed;
 import io.sirix.axis.DescendantAxis;
 import io.sirix.axis.PostOrderAxis;
 import io.sirix.io.StorageType;
@@ -212,7 +213,7 @@ public void testChicagoDescendantAxis() {
   // JVM flags: -XX:+UseShenandoahGC -Xlog:gc -XX:+UnlockExperimentalVMOptions -XX:+AlwaysPreTouch
   // -XX:+UseLargePages -XX:+DisableExplicitGC -XX:+PrintCompilation -XX:ReservedCodeCacheSize=1000m
   // -XX:+UnlockDiagnosticVMOptions -XX:+PrintInlining -XX:EliminateAllocationArraySizeLimit=1024
-  @Disabled
+  //@Disabled
   @Test
   public void testShredderAndTraverseChicago() {
     logger.info("start");
diff --git a/bundles/sirix-core/src/test/java/io/sirix/settings/VersioningTest.java b/bundles/sirix-core/src/test/java/io/sirix/settings/VersioningTest.java
index 27e4a60bc..f42f466ea 100644
--- a/bundles/sirix-core/src/test/java/io/sirix/settings/VersioningTest.java
+++ b/bundles/sirix-core/src/test/java/io/sirix/settings/VersioningTest.java
@@ -323,7 +323,8 @@ public void test() {
         assertEquals((Constants.NDP_NODE_COUNT * 10) - 1, wtx.getNodeKey());
         try (final XmlNodeReadOnlyTrx rtx = manager.beginNodeReadOnlyTrx()) {
           for (int i = 0; i < Constants.NDP_NODE_COUNT - 1; i++) {
-            assertTrue(rtx.moveToFirstChild());
+            final boolean moved = rtx.moveToFirstChild();
+            assertTrue(moved);
           }
           move(rtx);
           move(rtx);