PK56283: AN INCORRECT OUTPUT RETURNED FOR A QUERY CONTAINING SET FUNCTIONS, GROUP BY AND UNION

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• AN INCORRECT OUTPUT RETURNED FOR A QUERY CONTAINING SET
  FUNCTIONS, GROUP BY AND UNION
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: For all DB2 z/OS users who have queries      *
  *                 containing UNION or UNION ALL and at least   *
  *                 one union leg contains join and GROUP BY.    *
  ****************************************************************
  * PROBLEM DESCRIPTION: An incorrect result can occur when a    *
  *                      query has the following conditions      *
  *                      true:                                   *
  *                      1. Contains UNION or UNION ALL; AND     *
  *                      2. At least one UNION leg contains      *
  *                         join and GROUP BY; AND               *
  *                      3. The join column is one of the        *
  *                         grouping columns.                    *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  An incorrect result can occur when a query has the following
  conditions true:
  1. Contains UNION or UNION ALL; AND
  2. At least one UNION leg contains join and GROUP BY; AND
  3. The join column is one of the grouping columns.
  
  For example:
  SELECT T1.C1, SUM(T1.C3)
  FROM   T1, T2
  WHERE  T1.C1 = T2.C1
  GROUP BY T1.C1
  UNION
  SELECT ...
  
  An incorrect result occurs because DB2 may choose an erroneous
  access path in the above situation.  DB2 incorrectly processes
  set function evaluation with the erroneous access path.
  
  Additional Keywords:
  SQLINCORR INCORROUT SQLUNION SQLUNIONALL SQLJOIN SQLGROUPBY
  

Problem conclusion

• With corrected DB2 logic, the erroneous access path, which
  can cause the incorrect result, is avoided.
  

Temporary fix

• *********
  * HIPER *
  *********
  

Comments

APAR Information

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

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

  UK32175 UK32176

Modules/Macros

• DSNXOPRP DSNXOPRS
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• R810 PSY UK32175

     UP07/12/29 P F712

• R910 PSY UK32176

     UP07/12/29 P F712

Fix is available

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