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  1. Hive
  2. HIVE-23042

Merge queries to a single one for updating MIN_OPEN_TXNS table

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    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 4.0.0
    • Component/s: Transactions
    • Labels:
      None

      Description

      When opening a new transaction we issue 2 queries to update the MIN_OPEN_TXN table.

      <SELECT MIN("TXN_ID") FROM "TXNS" WHERE "TXN_STATE" = 'o'>
      <insert into "MIN_HISTORY_LEVEL" ("MHL_TXNID", "MHL_MIN_OPEN_TXNID") values(763, 763)>
      

      This could be archived with a single query faster, if we do not open transactions in batch, like:

      <INSERT INTO "MIN_HISTORY_LEVEL" ("MHL_TXNID", "MHL_MIN_OPEN_TXNID")
        SELECT ?, MIN("TXN_ID") FROM "TXNS" WHERE "TXN_STATE" = 'o'>
      

        Attachments

        1. HIVE-23042.2.patch
          13 kB
          Peter Vary
        2. HIVE-23042.3.patch
          13 kB
          Peter Vary
        3. HIVE-23042.4.patch
          13 kB
          Peter Vary
        4. HIVE-23042.patch
          13 kB
          Peter Vary

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            People

            • Assignee:
              pvary Peter Vary
              Reporter:
              pvary Peter Vary
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              Dates

              • Created:
                Updated:
                Resolved: