IBM Support

IT31146: ANTIJOIN BLOCKED WHEN QUERY HAS SIDE EFFECTS

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APAR status

  • Closed as program error.

Error description

  • Db2 query may show poor performance since antijoin is not formed
    due to presence of side effect in the query, although the side
    effect is not dependent on the query block that can be
    considered for antijoin.
    

Local fix

  • Add select * on the subquery having not exists and also add
    order by to the end of that added select. In column store along
    with that, use registry setting DB2COMPOPT=NO_OBELIM
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    

Problem conclusion

Temporary fix

Comments

APAR Information

  • APAR number

    IT31146

  • Reported component name

    DB2 FOR LUW

  • Reported component ID

    DB2FORLUW

  • Reported release

    B10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2019-12-03

  • Closed date

    2021-03-15

  • Last modified date

    2021-03-15

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

    IT31138

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

Fix information

  • Fixed component name

    DB2 FOR LUW

  • Fixed component ID

    DB2FORLUW

Applicable component levels

[{"Line of Business":{"code":"LOB10","label":"Data and AI"},"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSEPGG","label":"Db2 for Linux, UNIX and Windows"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"11.1"}]

Document Information

Modified date:
16 March 2021