IT25195: QUERIES CONTAINING OUTER JOINS AND GROUP BY CLAUSES MIGHT PRODUCE WRONG RESULTS

Db2 Version 11.1 Mod4 Fix Pack4 iFix001 for Linux, UNIX, and Windows
Db2 Version 11.1 Mod 4 Fix Pack 4 for Linux, UNIX, and Windows
Db2 Version 11.1 Mod 4 Fix Pack 6 for Linux, UNIX, and Windows
Db2 Version 11.1 Mod 4 Fix Pack 5 for Linux, UNIX, and Windows
Db2 Version 11.1 Mod 4 Fix Pack 7 for Linux, UNIX, and Windows

APAR status

• Closed as program error.

Error description

• Users might find wrong results from a query that has the
  following characteristics:
  1. the query has at least one outer join
  2. the row preserving side of this outer join outputs much less
  rows than the other side - the null producing side of the outer
  join
  3. there is group by clause on the null producing side of the
  outer join
  4. the row preserving side of the outer join cannot produce a
  unique key
  

Local fix

• DB2COMPOPT=NO_GBPU
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * Db2 Version 11.1                                             *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * See Error Description                                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Upgrade to Db2 Version 11.1 Mod 4 Fix Pack 4.                *
  ****************************************************************
  

Problem conclusion

• Problem was first fixed in Db2 Version 11.1 Mod 4 Fix Pack 4.
  

Temporary fix

Comments

APAR Information

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

  IT25147

• 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

• RB10 PSN

     UP