Yu-Wen Lai created HIVE-23846:
---------------------------------

             Summary: Avoid unnecessary serialization and deserialization of 
bitvectors
                 Key: HIVE-23846
                 URL: https://issues.apache.org/jira/browse/HIVE-23846
             Project: Hive
          Issue Type: Bug
          Components: Standalone Metastore
            Reporter: Yu-Wen Lai
            Assignee: Yu-Wen Lai


In the method *getNdvEstimator* of <datatype>*ColumnStatsDataInspector*, it 
will call isSetBitVectors(), in which it serializes the bitvectors again when 
we already have deserialized bitvectors _ndvEstimator_. For example, we can see 
this pattern from 
[LongColumnStatsDataInspector|[https://github.com/apache/hive/blob/master/standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/columnstats/cache/LongColumnStatsDataInspector.java#L106]].

This method could check if the _ndvEstimator_ is set first so that it won't 
need to serialize and deserialize back.



--
This message was sent by Atlassian Jira
(v8.3.4#803005)

Reply via email to