IBM Support

JR27846: A 'NOT IN' SUBQUERY HAS BEEN INTERNALLY REWRITTEN TO FORM A COMMON SUBEXPRESSION AND PREVENT FURTHER OPTIMIZATION.

Subscribe

You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • A 'NOT IN' subquery has been internally rewritten to form a
    common subexpression and prevent further optimization.
    
    This can lead to a rewritten query that prohibits potentially
    beneficial access plans.
    
    In some cases this can be avoided by using :
    db2set DB2_ANTIJOIN=EXTEND
    

Local fix

  • db2set DB2_ANTIJOIN=EXTEND
    

Problem summary

  • Users Affected : users with queries having NOT IN subqueries
     Problem Description : possible suboptimal performance
     Problem Summary : This apar will ensure optimal performance for
    such queries.
    

Problem conclusion

  • First fixed in DB2 UDB Version 9.5, FixPak 1
    

Temporary fix

Comments

APAR Information

  • APAR number

    JR27846

  • Reported component name

    DB2 UDB ESE WIN

  • Reported component ID

    5765F4101

  • Reported release

    950

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2007-11-14

  • Closed date

    2008-05-05

  • Last modified date

    2008-05-05

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

    JR25451

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

Fix information

  • Fixed component name

    DB2 UDB ESE WIN

  • Fixed component ID

    5765F4101

Applicable component levels

  • R950 PSY

       UP

[{"Business Unit":{"code":"BU048","label":"IBM Software"},"Product":{"code":"SSEPGG","label":"DB2 for Linux, UNIX and Windows"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"950","Edition":"","Line of Business":{"code":"LOB10","label":"Data and AI"}}]

Document Information

Modified date:
05 May 2008