IBM Support

IT36937: IF ROW BEING SORTED IS VERY WIDE MEMORY OVERWRITES OR WRONG RESULTS ARE POSSIBLE.

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APAR status

  • Closed as program error.

Error description

  • IF SORT IS DONE IN ROWSTORE LOGIC, NOT UNDER CTQ (COLUMNAR
    LOGIC) AND ROW GOING THROUGH SORT IS VERY WIDE:
    length of all fixed length columns + (number of variable length
    columns)*4 or 5 (depending on null-ability) is wider than 65535,
    then it is possible that during sort we will overwrite memory
    and
    cause traps or SQL0901 errors or wrong results.
    
    Examples of stacks for a trap:
    
    6   __intel_ssse3_rep_memcpy
    7   sqlsUnformatRow
    8   sqlsfetc
    9   sqlriFetch
    10 sqlrita
    11 sqlriSectInvoke
    12 sqlrr_process_fetch_request
    
    
    9         sqle_panic
    10       sqldValidateData
    11       sqldValFromFixed
    12       sqldExtractZvalFromRec
    13       sqldEvalDataPred
    14       sqlsEvalPred
    15       sqlsfetc
    

Local fix

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

    IT36937

  • Reported component name

    DB2 FOR LUW

  • Reported component ID

    DB2FORLUW

  • Reported release

    B50

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2021-05-18

  • Closed date

    2021-06-21

  • Last modified date

    2021-06-23

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

    IT36928

  • 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":"BU029","label":"Software"},"Product":{"code":"SSEPGG","label":"DB2 for Linux- UNIX and Windows"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"11.5"}]

Document Information

Modified date:
24 June 2021