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IT38495: DB2 MIGHT TERMINATE ABNORMALLY FOR QUERIES WITH MULTIPLE OUTER JOINS

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You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • If you have a a query that meets the following characteristics:
    1. Query with multiple Outer join and equi-join predicates
    2. Null producing side is a complex view
    3. Where clause with equality predicates referencing the join
    columns and constants
    4. Cost based
    
    it may trap in sqlnr_OJ_semi_join() with the following stack:
    
    sqlnr_OJ_semi_join
    sqlnr_qrwprep_phase2
    sqlnr_prep2_action
    sqlnr_comp
    sqlnr_seq
    sqlnr_rcci
    sqlnr_exe
    
    This problem starts to happen on v11.1.4.6, doesn't happen on
    previous versions.
    

Local fix

  • Set the following registry
    - with the optimization guideline to the affected queries:
    /* <OPTGUIDELINES>
            <REGISTRY>
               <OPTION NAME='DB2COMPOPT' VALUE='NOOJSJ'/>
            </REGISTRY>
    </OPTGUIDELINES> */
    or
    - at the instance level:
    db2set DB2COMPOPT=NOOJSJ -im
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * all                                                          *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Upgrade to 11.1.4.7                                          *
    ****************************************************************
    

Problem conclusion

  • Upgrade to 11.1.4.7
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT38495

  • 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

    2021-09-25

  • Closed date

    2022-04-17

  • Last modified date

    2022-04-17

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

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

    IT38518

Fix information

  • Fixed component name

    DB2 FOR LUW

  • Fixed component ID

    DB2FORLUW

Applicable component levels

  • RB10 PSN

       UP

[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSEPGG","label":"DB2 for Linux- UNIX and Windows"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"11.1","Line of Business":{"code":"LOB10","label":"Data and AI"}}]

Document Information

Modified date:
03 May 2022