IBM Support

IZ01924: QUERY PERFORMANCE MAY BE SLOW WHEN DB2 FAILS TO CONVERT IN SUBQUERY TO INNER JOIN.

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You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • In some cases, the columns derived from the null producing side
    of the outer join trigger other query rewrites, DB2 may fail to
    convert IN subquery predicates to inner joins. As a result,
    the subquery predicate (seen as EXISTS in the db2exfmt output)
    remains unchanged and the query may run slow.
    

Local fix

  • Not available
    

Problem summary

  • Users affected: All
    

Problem conclusion

  • Problem was first fixed in Version 9.1 Fix Pack 5 (s080512).
    

Temporary fix

Comments

APAR Information

  • APAR number

    IZ01924

  • Reported component name

    DB2 CEE AIX

  • Reported component ID

    5765F3000

  • Reported release

    910

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2007-07-27

  • Closed date

    2008-06-23

  • Last modified date

    2008-06-23

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

    IZ01771

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

    IZ11439

Fix information

  • Fixed component name

    DB2 CEE AIX

  • Fixed component ID

    5765F3000

Applicable component levels

  • R910 PSN

       UP

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Document Information

Modified date:
23 June 2008