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  1. Hive
  2. HIVE-3562

Some limit can be pushed down to map stage

    Details

    • Type: Bug Bug
    • Status: Closed
    • Priority: Trivial Trivial
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 0.12.0
    • Component/s: None
    • Labels:
      None

      Description

      Queries with limit clause (with reasonable number), for example

      select * from src order by key limit 10;
      

      makes operator tree,
      TS-SEL-RS-EXT-LIMIT-FS

      But LIMIT can be partially calculated in RS, reducing size of shuffling.
      TS-SEL-RS(TOP-N)-EXT-LIMIT-FS

      1. HIVE-3562.D5967.1.patch
        19 kB
        Phabricator
      2. HIVE-3562.D5967.2.patch
        43 kB
        Phabricator
      3. HIVE-3562.D5967.3.patch
        66 kB
        Phabricator
      4. HIVE-3562.D5967.4.patch
        83 kB
        Phabricator
      5. HIVE-3562.D5967.5.patch
        91 kB
        Phabricator
      6. HIVE-3562.D5967.6.patch
        86 kB
        Phabricator
      7. HIVE-3562.D5967.7.patch
        103 kB
        Phabricator
      8. HIVE-3562.D5967.8.patch
        105 kB
        Phabricator
      9. HIVE-3562.D5967.9.patch
        104 kB
        Phabricator

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            • Assignee:
              Navis
              Reporter:
              Navis
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              Dates

              • Created:
                Updated:
                Resolved:

                Development