Derby
  1. Derby
  2. DERBY-3934

Improve performance of reading modified Clobs

    Details

    • Type: Improvement Improvement
    • Status: Closed
    • Priority: Major Major
    • Resolution: Fixed
    • Affects Version/s: 10.5.1.1
    • Fix Version/s: 10.5.1.1
    • Component/s: JDBC
    • Labels:
      None
    • Bug behavior facts:
      Performance

      Description

      The performance of reading modified Clobs is poor, which is demonstrated by running a test program selecting a 10 MB Clob and then getting the contents using getSubString:

      • unmodified Clob (StoreStreamClob) : ~1 300 ms
      • modified Clob (TemporaryClob): ~156 000 ms

      In this case, the Clob was modified by changing the first character.

      A number of subtasks will be created to handle the various issues, which will be related to both performance and code cleanup.
      For a brief overview, see http://www.nabble.com/Suggestion-for-improving-ClobUpdatableReader-and-related-code-to20308303.html

      1. derby-3934-1a-clob_replace_test.diff
        3 kB
        Kristian Waagan
      2. derby-3934-2a-intclob_new_methods.diff
        4 kB
        Kristian Waagan
      3. derby-3934-3a-clobupdreader_utf8reader.diff
        30 kB
        Kristian Waagan
      4. derby-3934-3a-clobupdreader_utf8reader.stat
        0.3 kB
        Kristian Waagan
      5. derby-3934-4a-getinternalreader_cachedlength.diff
        12 kB
        Kristian Waagan
      6. derby-3934-5a-UTF8Reader_cleanup.diff
        8 kB
        Kristian Waagan
      7. derby-3934-6a-UTF8Reader_remove_method.diff
        1 kB
        Kristian Waagan

        Activity

        Kristian Waagan created issue -
        Kristian Waagan made changes -
        Field Original Value New Value
        Status Open [ 1 ] In Progress [ 3 ]
        Kristian Waagan made changes -
        Attachment derby-3934-1a-clob_replace_test.diff [ 12394660 ]
        Kristian Waagan made changes -
        Derby Info [Patch Available]
        Kristian Waagan made changes -
        Attachment derby-3934-2a-intclob_new_methods.diff [ 12394677 ]
        Kristian Waagan made changes -
        Derby Info [Patch Available]
        Kristian Waagan made changes -
        Kristian Waagan made changes -
        Kristian Waagan made changes -
        Fix Version/s 10.5.0.0 [ 12313010 ]
        Kristian Waagan made changes -
        Attachment derby-3934-5a-UTF8Reader_cleanup.diff [ 12398233 ]
        Kristian Waagan made changes -
        Derby Info [Patch Available]
        Kristian Waagan made changes -
        Derby Info [Patch Available]
        Kristian Waagan made changes -
        Kristian Waagan made changes -
        Status In Progress [ 3 ] Closed [ 6 ]
        Resolution Fixed [ 1 ]
        Myrna van Lunteren made changes -
        Affects Version/s 10.5.1.1 [ 12313771 ]
        Affects Version/s 10.5.0.0 [ 12313010 ]
        Fix Version/s 10.5.1.1 [ 12313771 ]
        Fix Version/s 10.5.0.0 [ 12313010 ]
        Gavin made changes -
        Workflow jira [ 12445637 ] Default workflow, editable Closed status [ 12799049 ]

          People

          • Assignee:
            Kristian Waagan
            Reporter:
            Kristian Waagan
          • Votes:
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            Watchers:
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            Dates

            • Created:
              Updated:
              Resolved:

              Development