Uploaded image for project: 'Hive'
  1. Hive
  2. HIVE-17767

Rewrite correlated EXISTS/IN subqueries into LEFT SEMI JOIN

    XMLWordPrintableJSON

Details

    • Improvement
    • Status: Closed
    • Major
    • Resolution: Fixed
    • None
    • 3.0.0
    • Query Planning
    • None

    Description

      Currently such queries are written into group by + inner join with value generator and is inefficient. Value generator consists of join with outer query to fetch all correlated values. This value generator could be completely eliminated if such queries are instead rewritten into LEFT SEMI JOIN.
      Note that to do this first hive need to support LEFT SEMI JOIN with non-equi condition (HIVE-17766).

      Attachments

        1. HIVE-17767.7.patch
          1.26 MB
          Vineet Garg
        2. HIVE-17767.6.patch
          1.26 MB
          Vineet Garg
        3. HIVE-17767.5.patch
          1.25 MB
          Vineet Garg
        4. HIVE-17767.4.patch
          1.11 MB
          Vineet Garg
        5. HIVE-17767.3.patch
          1.18 MB
          Vineet Garg
        6. HIVE-17767.2.patch
          1.18 MB
          Vineet Garg
        7. HIVE-17767.1.patch
          591 kB
          Vineet Garg

        Issue Links

          depends upon

          Improvement - An improvement or enhancement to an existing feature or task. HIVE-17766 Support non-equi LEFT SEMI JOIN

          • Major - Major loss of function.
          • Closed
          links to

          Web Link ReviewBoard

          Activity

            People

              vgarg Vineet Garg
              vgarg Vineet Garg
              Votes:
              0 Vote for this issue
              Watchers:
              3 Start watching this issue

              Dates

                Created:
                Updated:
                Resolved: