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IT34063: BOOLEAN PREDICATES RETURN WRONG RESULT WITH NULL INPUT

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APAR status

  • Closed as program error.

Error description

  • The boolean predicates (IS TRUE, IS NOT FALSE etc.) are
    returning a NULL result with NULL input.  Boolean predicates
    should never return a NULL result.  When used in a where-clause,
    the problem may not be noticeable since a NULL (UNKNOWN) result
    in a where-clause returns 0 rows.  However, the problem is
    apparent if the boolean predicate is preceded with NOT in the
    where-clause:
    
         create table T (B boolean)
         DB20000I  The SQL command completed successfully.
    
         insert into T values (NULL)
         DB20000I  The SQL command completed successfully.
    
         select * from T where not(B is false)
    
         B
         ------
                <-- Wrong, one row should be returned
           0 record(s) selected.
    
    Also, the problem can be seen when the boolean predicate is
    referenced in a select-list:
    
         select B is true from T
    
         1
         ------
              - <-- Wrong, should be 0
    
           1 record(s) selected.
    

Local fix

  • Use the corresponding built-in functions instead: SYSIBM.ISTRUE,
    SYSIBM.ISNOTTRUE etc.
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * ALL                                                          *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Upgrade to Db2 version 11.1 fix pack 6                       *
    ****************************************************************
    

Problem conclusion

  • First fixed in Db2 version 11.1 fix pack 6
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT34063

  • Reported component name

    DB2 FOR LUW

  • Reported component ID

    DB2FORLUW

  • Reported release

    B10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2020-08-31

  • Closed date

    2021-03-17

  • Last modified date

    2021-03-29

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

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

    IT35060

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