Fix AvgHistogramPercentileFunction doesn't have proper field definition for ranks. (#12927)

Author: wu-sheng

docs/en/changes/changes.md

@@ -51,6 +51,7 @@
 * Fix missing remote endpoint IP address in span query of zipkin query module.
 * Fix `hierarchy-definition.yml` config file packaged into start.jar wrongly.
 * Add `bydb.dependencies.properties` config file to define server dependency versions.
+* Fix `AvgHistogramPercentileFunction` doesn't have proper field definition for `ranks`.
 
 #### UI
 

oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/meter/function/avg/AvgHistogramPercentileFunction.java

@@ -109,6 +109,7 @@ public abstract class AvgHistogramPercentileFunction extends Meter implements Ac
     @Getter
     @Setter
     @Column(name = RANKS, storageOnly = true)
+    @BanyanDB.MeasureField
     private IntList ranks = new IntList(10);
 
     private boolean isCalculated = false;

oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/storage/annotation/BanyanDB.java

@@ -124,6 +124,8 @@ enum IndexType {
 
     /**
      * MeasureField defines a column as a measure's field.
+     * The measure field has a significant difference from no-indexing tag.
+     * The measure fields are stored in another file, but no-indexing tag is stored in the same file with the indexing tags.
      * <p>
      * Annotated: the column is a measure field.
      * Unannotated: the column is a measure tag.
@@ -219,6 +221,8 @@ enum AnalyzerType {
     /**
      * IndexMode is used to indicate the index mode of the metric.
      * All columns in the metric will be stored in the index exclusively.
+     * When an entity column is not used in query condition, only {@link Column#storageOnly()} is allowed.
+     * No {@link MeasureField} is allowed for those columns in IndexMode entity.
      *
      * @since 10.2.0
      */