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  1. Derby
  2. DERBY-5284

A derby crash at exactly right time during a btree split can cause a corrupt db which can not be booted.



    • Issue & fix info:
      High Value Fix, Patch Available
    • Bug behavior facts:
      Crash, Data corruption


      A derby crash at exactly wrong time during a btree split can cause a corrupt db which can not be booted.

      A problem in the split code and exact wrong timing of a crash can leave the database in as state
      where undo of purge operations corrupts index pages during redo and can cause recovery boot
      to never succeed and thus the database never to be booted. At hight level what happens is that
      a purge happens on a page and before it commits another transactions uses the space of the
      purge to do an insert and then commits, then the system crashes before the purging transactions
      gets a chance to commit. During undo the purge expects there to be space to undo the purge
      but there is not, and it corrupts the page in various ways depending on the size and placement
      of the inserts. The error that actually returns to user varies from sane to insane as the problem
      is actually noticed after the corruption occurs rather than during the undo.


        1. DERBY-5284_diff.txt
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          Mike Matrigali

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              • Assignee:
                mikem Mike Matrigali
                mikem Mike Matrigali
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