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  1. Derby
  2. DERBY-4050

Multithreaded clob update causes growth in table that does not get reclaimed

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    • Issue & fix info:
      High Value Fix, Release Note Needed

      Description

      Doing a multithreaded update of a Clob table causes table growth that does not get reclaimed except by compressing the table. The reproduction has a table with two threads. One thread updates row 1 repeatedly with 33,000 character clob. The other thread updates row 2 with a small clob, "hello". The problem occurs back to 10.2 but seems much worse on trunk than 10.2. The trunk database grew to 273MB on trunk after 10000 updates of each row. The 10.2 database grew only to 25MB. If the update is synchronized there is no growth.
      I will attach the repro.

        Attachments

        1. ClobGrowth.java
          4 kB
          Katherine Marsden
        2. derby.log.growth
          94 kB
          Katherine Marsden
        3. derby.log.nogrowth
          70 kB
          Katherine Marsden
        4. derby-4050_more_debug.diff
          3 kB
          Mike Matrigali
        5. derby-4050_diff.txt
          9 kB
          Katherine Marsden
        6. releaseNote.html
          3 kB
          Katherine Marsden
        7. derby-4050_diff2.txt
          10 kB
          Katherine Marsden
        8. derby.log-32w100t.txt
          5 kB
          Kristian Waagan
        9. releaseNote.html
          3 kB
          Myrna van Lunteren

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              • Assignee:
                kmarsden Katherine Marsden
                Reporter:
                kmarsden Katherine Marsden
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                • Created:
                  Updated:
                  Resolved: