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  1. Hive
  2. HIVE-1194

sorted merge join

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Details

    • New Feature
    • Status: Closed
    • Major
    • Resolution: Fixed
    • None
    • 0.6.0
    • Query Processor
    • None
    • Reviewed

    Description

      If the input tables are sorted on the join key, and a mapjoin is being performed, it is useful to exploit the sorted properties of the table.
      This can lead to substantial cpu savings - this needs to work across bucketed map joins also.

      Since, sorted properties of a table are not enforced currently, a new parameter can be added to specify to use the sort-merge join.

      Attachments

        1. hive-1194-2010-02-28.patch
          84 kB
          He Yongqiang
        2. hive-1194-2010-3-2.2.patch
          304 kB
          He Yongqiang
        3. hive-1194-2010-3-2.patch
          304 kB
          He Yongqiang
        4. hive-1194-2010-3-3.patch
          380 kB
          He Yongqiang
        5. hive-1194-2010-3-3-2.patch
          380 kB
          He Yongqiang
        6. hive-1194-2010-3-4.patch
          396 kB
          He Yongqiang

        Issue Links

          relates to

          Bug - A problem which impairs or prevents the functions of the product. HIVE-1210 code cleanup for sort-merge join

          • Major - Major loss of function.
          • Open

          Bug - A problem which impairs or prevents the functions of the product. HIVE-1213 sort-merge join does not work for sub-queries

          • Major - Major loss of function.
          • Open

          Bug - A problem which impairs or prevents the functions of the product. HIVE-1552 Nulls are not handled in Sort Merge MapJoin

          • Major - Major loss of function.
          • Resolved

          Improvement - An improvement or enhancement to an existing feature or task. HIVE-1214 sort-merge join should work for descending sort also

          • Major - Major loss of function.
          • Open

          Activity

            People

              he yongqiang He Yongqiang
              namit Namit Jain
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              Dates

                Created:
                Updated:
                Resolved: