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PM82258: DROP MAY PERFORM SLOWLY AFTER EXECUTING A LOT OF DROP STATEMENTS IN THE SAME THREAD

A fix is available

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APAR status

  • Closed as program error.

Error description

  • DROP may perform slowly after executing a lot of DROP statements
    in the same thread
    

Local fix

  • N/A
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED: DB2 9 for z/OS and DB2 10 for z/OS users     *
    *                 that specify a Declared Global Temporary     *
    *                 Table (DGTT) in a DROP statement.            *
    ****************************************************************
    * PROBLEM DESCRIPTION: Users may encounter poor performance    *
    *                      for long running threads which          *
    *                      execute DROP statements with DGTT       *
    *                      specified.                              *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    Users may encounter poor performance when a DGTT is specified
    in a DROP statement. This may occur when many DGTTs are being
    dropped in the same long running thread because DB2 keeps a
    DB2 thread/connection-level history of DB2 objects that are
    dropped/altered by applications in a specific DB2 thread.
    This history tracking of dropped/altered objects is thread
    based and normally must persist for the life of the DB2 thread.
    After a very high threshold point on the single long running
    DB2 thread/connection, the DGTT change history may accumulate
    and negatively impact performance.
    

Problem conclusion

  • Performance has been optimized for dropping of DGTTs when
    many DGTTs have been dropped in the same DB2 thread, such that
    the DGTT history will no longer cause the reported performance
    degradation.
    
    ADDITIONAL KEYWORDS:
    SQLDGTT PERFM SQLPERFORMANCE
    

Temporary fix

  • *********
    * HIPER *
    *********
    

Comments

APAR Information

  • APAR number

    PM82258

  • Reported component name

    DB2 OS/390 & Z/

  • Reported component ID

    5740XYR00

  • Reported release

    910

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2013-02-06

  • Closed date

    2013-03-12

  • Last modified date

    2013-04-02

  • APAR is sysrouted FROM one or more of the following:

  • APAR is sysrouted TO one or more of the following:

    UK92479 UK92480

Modules/Macros

  • DSNXISB5
    

Fix information

  • Fixed component name

    DB2 OS/390 & Z/

  • Fixed component ID

    5740XYR00

Applicable component levels

  • RA10 PSY UK92479

       UP13/03/28 P F303

  • R910 PSY UK92480

       UP13/03/28 P F303

Fix is available

  • Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.

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Document Information

Modified date:
02 April 2013