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  1. #1
    Join Date
    Jun 2003

    Question Unanswered: rollforward backward recovery

    Using db2 7.2 DMS
    We restored and rolled forward a database up to a point in time. About a week's worth of data was rolled forward using the logs.
    The rollforward was successful, but we are missing some data that was entered in the database some 5 hours before the time given in rollforward command.

    The db2diag.log file has entries in this sequence (between the start and finish of this rollforward) -

    Rollforward has been initiated

    Using parallel recovery with 5 agents 64 QSets 448 queues and 2 chunks

    Invoking database rollforward forward recovery,
    lowtranlsn 00278353E556 minbufflsn 002783149E7A

    Invoking database rollforward backward recovery, nextlsn: 002a 611a 8ab3 .*a.

    Rollforward iteration completed

    I want to know what is meant by "rollforward backward recovery". Does it mean that it encountered a damaged or missing log and stopped somewhere in the middle before the specified roll forward time?
    If yes, is there a way to know the time up to which it actually rolled forward?

    Thanks in advance.

  2. #2
    Join Date
    Nov 2005
    rollforward backward recovery is the second phase in rollforward. To keep database in consistance status, it need to rollforward all the commited transaction and leave all the uncommited transaction out. In REDO phase it will rollforward everything and in UNDO phase it will clean up uncommited transactions.

    I'm not sure how to know the time up to which it actually rolled forward

  3. #3
    Join Date
    Nov 2004


    you specified you did pit recovery. in V7 the date/time is expressed in universal time and not local time..
    have a look up of this date time format, or do rollforward end of logs..(if possible)
    Best Regards, Guy Przytula
    DB2/ORA/SQL Services
    DB2 DBA & Advanced DBA Certified
    DB2 Dprop Certified

  4. #4
    Join Date
    Jun 2003
    Thanks for your responses.
    Good to know that a rollforward backward recovery is not an error situation.

    I did use the universal time instead of local.

    It looks like something done 5 hours ago might not be committed at the time given in rollforwad command. So it rolled back and thus not present in the recovered database.

    My guess was that some transactions that took place around the time given in rollforward would be inconsistent. But it turned out to be a far longer time.

    The "last committed transaction" time provided in the result of rollforward was 14:35, but the database doesnt have the data that was added at 10:00.

    I would like to know if someone has more information on how to estimate the time up to which the database is recovered after a rollforward.

    Thanks again.
    Last edited by preetim; 11-16-05 at 11:43.

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