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IT00336: STMM MAY UNNECESSARILY INCREASE PACKAGE CACHE SIZE

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You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • STMM may incorrectly calculate performance benefits for package
    cache when statements are invalidated.  For example, cached
    statements may be invalidated because of dependencies on dropped
    objects, and when those statements are executed again -
    necessitating recompilation, STMM may incorrectly calculate the
    compilation could be avoided with a larger package cache.
    
    The most obvious sign of this is that STMM increase the package
    cache configured size before it is reached.  This can be seen by
    comparing the logical usage high water mark in db2pd -db
    <database> -mempools against its configured size (current
    PCKCACHESZ setting, or the "configured size" from db2pd -db
    <database> -mempools on Version 10.1 and higher).
    

Local fix

  • use manual tuning of package cache
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * systems with self-tuning (STMM) of package cache enabled     *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Upgrade to DB2 Version 9.7 Fix Pack <n>                      *
    ****************************************************************
    

Problem conclusion

  • Problem first fixed in DB2 Version 9.7 Fix Pack 10
    

Temporary fix

  • see Local Fix
    

Comments

APAR Information

  • APAR number

    IT00336

  • Reported component name

    DB2 FOR LUW

  • Reported component ID

    DB2FORLUW

  • Reported release

    970

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2014-03-18

  • Closed date

    2014-11-11

  • Last modified date

    2014-11-11

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

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

    IT00363 IT00377

Modules/Macros

  • sqra
    

Fix information

  • Fixed component name

    DB2 FOR LUW

  • Fixed component ID

    DB2FORLUW

Applicable component levels

  • R970 PSN

       UP

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Document Information

Modified date:
11 November 2014