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IT36320: QUERY EXECUTION MAY FAIL FOR OUTER JOIN QUERIES WITH PREDICATES WITH CAST FUNCTIONS

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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 DPF system and a query that meets the following
    conditions :
    - query references multiple Outer joins
    - predicates in the ON clause reference Cast functions
    it may trap in sqlnr_OJ_semi_join()
    
    Example query:
    SELECT T1.C1
    FROM T1 LEFT OUTER JOIN T2 ON T2.C1 = 'ITRA'
         LEFT OUTER JOIN T3 ON T3.C1 = CAST(T1.C1 AS VARCHAR(200)) ;
    
    
    Example stack trace for the failing query:
    sqlnr_OJ_semi_join
    sqlnr_qrwprep_phase2
    sqlnr_prep2_action
    sqlnr_exe
    sqlnn_cmpl
    

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 11.5.6 or later                                   *
    ****************************************************************
    

Problem conclusion

  • Upgrade to 11.5.6 or later
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT36320

  • 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

    2021-03-23

  • Closed date

    2022-04-18

  • Last modified date

    2022-04-18

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

  • 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

  • RB50 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:
04 May 2022