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Go Back  dBforums > Database Server Software > DB2 > softmax 200 : crash recovery

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Old 08-11-11, 22:41
blazer789 blazer789 is offline
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softmax 200 : crash recovery

DB2 is has a transcation which is spanned across 5 log files before it has crashed. Softmax value set on the database is just 200 which means it requires only 2 log files during crash recovery. So does that mean that the transaction which is spanned across 5 log files cannot be recovered during a crash recovery.
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Old 08-12-11, 00:03
n_i n_i is offline
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No connection between the two statements. It's true that the database will try to ensure that only the two log files' worth of log records will need to be redone during recovery by writing bufferpool pages out to disk when the gap between logged changes and persisted changes exceeds 2 log files in your example (LSN gap page cleaning trigger).

However, whether the "long" (5 log files long) transaction can be recovered or not depends only on whether it was committed before the crash or not. If it was committed, DB2 will only need to replay 2 log files. If it was not committed, it will still replay 2 log files, but then undo the changes made by the uncommitted transaction, going back 5 log files.
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