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Thread: Lock problems

  1. #1
    Join Date
    Oct 2004
    Posts
    268

    Unanswered: Lock problems

    DB2 8.1 FP10 on AIX 5.3

    Our client is having lock problems when executing SQL against their database. They have much more data than we have and we are not having the same problem. Is there a way to trick DB2 to make it look like the database has larger volume of data in its tables than there actually is ?

    If there is, how ?

    Thanks for any help.

  2. #2
    Join Date
    Sep 2003
    Posts
    237
    Ask them to increase the database config. parameters LOCKLIST=5000 and MAXLOCKS=80; If their data is 5 times yours, LOCKLIST must be 5 times yours; also their SQLs containing update, delete must have frequent COMMITs.
    mota

  3. #3
    Join Date
    Oct 2004
    Posts
    268
    Any way to make that change I was asking ?

  4. #4
    Join Date
    Sep 2003
    Posts
    237
    You can reduce your LOCKLIST proportionately if you want to reproduce their problem at your site;that is making the db look bigger from a lock standpoint
    mota

  5. #5
    Join Date
    May 2003
    Location
    USA
    Posts
    5,737
    You can update the CARD column in SYSCAT.TABLES to indicate the number of rows you want DB2 to think exists. There are other columns in this and other tables that can also be updated.

    However, I would suggest that if executing runstats does not help (runstats on table table-name with distribution on key columns and indexes all), then I would try to alter the tables to volatile. Doing a reorg before running runstats would be preferable.
    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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