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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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    • 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

        Issue Links

          is related to

          Task - A task that needs to be done. DERBY-5356 Tracking for Derby space reclamation issues

          • Major - Major loss of function.
          • Open
          relates to

          Bug - A problem which impairs or prevents the functions of the product. DERBY-4054 Multithreaded clob update with exclusive table locking causes table growth that is not reclaimed

          • Major - Major loss of function.
          • Open

          Bug - A problem which impairs or prevents the functions of the product. DERBY-4055 Space may not be reclaimed if row locks are not available after three retries

          • Major - Major loss of function.
          • Open

          Bug - A problem which impairs or prevents the functions of the product. DERBY-4056 Space is not reclaimed when attempting to insert row that violates UNIQUE constraint

          • Major - Major loss of function.
          • Closed

          Improvement - An improvement or enhancement to an existing feature or task. DERBY-4057 Space is not reclaimed if transaction is rolled back

          • Major - Major loss of function.
          • Closed

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              kmarsden Katherine Marsden
              kmarsden Katherine Marsden
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              Dates

                Created:
                Updated:
                Resolved: