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IT01073: INCORRECT RESULTS MIGHT BE PRODUCED WITH PREDICATES INVOLVING NULL CONSTANTS

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APAR status

  • Closed as program error.

Error description

  • Under rare scenarios, DB2 might produce an incorrect result if
    the following conditions are true:
    1) The query contains a NULL constant in predicate
    2) The predicate is of the form expression <relop> NULL where
    <relop> can be =,>=,<=
    3) The expression is either a CASE expression or a NULLIF
    function
    4) The output of the expression is guaranteed to be NULL
    
    eg.
    select * from t1 where NULLIF (c1, c1) >= Cast(NULL as int);
    select * from t1 where case when c1 = c1 then NULL else c1 end
    >= cast(NULL as BIGINT);
    

Local fix

  • 1) drop the redundant predicate
    2) Change the query optimization level to 0
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * All users                                                    *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Upgrade to DB2 version 10.1.0.4.                             *
    ****************************************************************
    

Problem conclusion

  • The problem is first fixed in DB2 version 10.1.0.4.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT01073

  • Reported component name

    DB2 FOR LUW

  • Reported component ID

    DB2FORLUW

  • Reported release

    A10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2014-04-15

  • Closed date

    2014-05-08

  • Last modified date

    2015-04-21

Fix information

  • Fixed component name

    DB2 FOR LUW

  • Fixed component ID

    DB2FORLUW

Applicable component levels

  • RA10 PSN

       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":"10.1","Edition":"","Line of Business":{"code":"LOB10","label":"Data and AI"}}]

Document Information

Modified date:
21 April 2015