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  1. Derby
  2. DERBY-4849

Re-compilation may cause duplicate entries in the XPLAIN table

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Details

    • Bug
    • Status: Closed
    • Minor
    • Resolution: Fixed
    • 10.6.2.1, 10.7.1.1
    • 10.6.2.2, 10.7.1.1
    • SQL
    • None

    Description

      If happening at the right moment, a re-compilation request may cause duplicate entries in the XPLAIN statement tables.
      I have only confirmed this for the SYSXPLAIN_STATEMENTS table, and I do not know if the other XPLAIN tables are affected.

      The error is highly intermittent, and so far I have only been able to trigger it when testing the automatic index statistics update prototype.
      See the attached stack-trace for some more details.

      Attachments

        1. derby-4849-1a-narrow_fix.diff
          5 kB
          Kristian Waagan
        2. derby-4849-2a-broad_fix.diff
          5 kB
          Kristian Waagan
        3. derby-4849-2b-broad_fix_with_test.diff
          15 kB
          Kristian Waagan
        4. derby-4849-2b-broad_fix_with_test.stat
          0.4 kB
          Kristian Waagan
        5. derby-4849-2c-broad_fix_with_test.diff
          15 kB
          Kristian Waagan
        6. derby-4849-xplain_duplicate_stacktrace.txt
          11 kB
          Kristian Waagan

        Issue Links

          requires

          Bug - A problem which impairs or prevents the functions of the product. DERBY-4881 Deadlock accessing SYS.SYSSTATISTICS

          • Minor - Minor loss of function, or other problem where easy workaround is present.
          • Closed

          Activity

            People

              kristwaa Kristian Waagan
              kristwaa Kristian Waagan
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              Dates

                Created:
                Updated:
                Resolved: