Uploaded image for project: 'Spark'
  1. Spark
  2. SPARK-32573

Anti Join Improvement with EmptyHashedRelation and EmptyHashedRelationWithAllNullKeys

    XMLWordPrintableJSON

Details

    • Improvement
    • Status: Resolved
    • Minor
    • Resolution: Fixed
    • 3.0.0
    • 3.1.0
    • SQL
    • None

    Description

      InĀ SPARK-32290, we introduced several new types of HashedRelation

      • EmptyHashedRelation
      • EmptyHashedRelationWithAllNullKeys

      They were all limited to used only in NAAJ scenario. These new HashedRelation could be applied to other scenario for performance improvements.

      • EmptyHashedRelation could also be used in Normal AntiJoin for fast stop
      • While AQE is on and buildSide is EmptyHashedRelationWithAllNullKeys, can convert NAAJ to a Empty LocalRelation to skip meaningless data iteration since in Single-Key NAAJ, if null key exists in BuildSide, will drop all records in streamedSide.

      This Patch including two changes.

      • using EmptyHashedRelation to do fast stop for common anti join as well
      • In AQE, eliminate BroadcastHashJoin(NAAJ) if buildSide is a EmptyHashedRelationWithAllNullKeys

      Attachments

        Activity

          People

            leanken Leanken.Lin
            leanken Leanken.Lin
            Votes:
            0 Vote for this issue
            Watchers:
            3 Start watching this issue

            Dates

              Created:
              Updated:
              Resolved: