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Thread: Oracle V DB2

  1. #1
    Join Date
    Apr 2004
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    Unanswered: Oracle V DB2

    Can someone confirm DB2 does not act like Oracle in the case below with the settings below?


    2. If DB2 behaves like Oracle, then the committed transaction is placed on a queue to be updated and that did not occur before the next query.


    [i] DB2_SKIPINSERTED=ON
    [i] DB2_SKIPDELETED=ON

    Thanks

  2. #2
    Join Date
    Jun 2003
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    Toronto, Canada
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    Provided Answers: 1
    Quote Originally Posted by redwolf
    Can someone confirm DB2 does not act like Oracle in the case below with the settings below?


    2. If DB2 behaves like Oracle, then the committed transaction is placed on a queue to be updated and that did not occur before the next query.


    [i] DB2_SKIPINSERTED=ON
    [i] DB2_SKIPDELETED=ON

    Thanks
    No, it does not.

    This affects the rows that have been inserted or deleted but not committed yet. These rows are locked, and normally a query with a sufficient isolation level would block when hit one of such rows. The two registry variables change that behaviour so that the query skips uncommitted rows.

    When the transaction commits all its locks are released.
    ---
    "It does not work" is not a valid problem statement.

  3. #3
    Join Date
    May 2003
    Location
    USA
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    5,737
    As already noted, the two environment settings do not make DB2 work the same as Oracle with regard to locking. However, the parameters do have the benefit of increasing concurrency and reducing DB2 lock contention, so it shares some advantages with Oracle in that regard. An even though these parameters do not make DB2 the same as Oracle, they increase concurrency a lot more efficiently than the Oracle optimistic locking and read consistency scheme.
    M. A. Feldman
    IBM Certified DBA on DB2 for Linux, UNIX, and Windows
    IBM Certified DBA on DB2 for z/OS and OS/390

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