IT08458: NON-OPTIMAL ACCESS PLAN MIGHT BE GENERATED FOR A COMPLEX QUERY THAT PRODUCES A SQL0437W WITH RC=1

IT08458: NON-OPTIMAL ACCESS PLAN MIGHT BE GENERATED FOR A COMPLEX QUERY THAT PRODUCES A SQL0437W WITH RC=1

 https://www.ibm.com/support/pages/apar/IT08458

Fixes are available

DB2 Version 10.5 Fix Pack 9 for Linux, UNIX, and Windows
DB2 Version 10.5 Fix Pack 10 for Linux, UNIX, and Windows
DB2 Version 10.5 Fix Pack 11 for Linux, UNIX, and Windows

APAR status

• Closed as program error.

   

Error description

• The DB2 optimizer might generate a non-optimal access plan for
  complex queries containing one or more equality join predicates.
  This problem is more likely to occur when STMTHEAP is set to
  AUTOMATIC and after applying DB2 Version 9.7 Fix Pack 8,9, or
  10.
  
  You can identify this issue by gathering an EXPLAIN of the
  query.  If the problem is hit, you will receive a SQL0437W with
  rc=1 during query compilation, and the EXPLAIN output will
  include filter factor estimates and cardinality estimates of 0.
  

   

Local fix

• You can increase the STMTHEAP to avoid the problem.  To identify
  an appropriate size, you can gather an EXPLAIN of the query and
  set it to a value larger than the one shown under the HEAPUSE
  argument of the RETURN operator.
  

   

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * all                                                          *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * See Error Description                                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * db2_v105fp7                                                  *
  ****************************************************************
  

   

Problem conclusion

• db2_v105fp7
  

   

Temporary fix

Comments

APAR Information

• APAR number

  IT08458

• Reported component name

  DB2 FOR LUW

• Reported component ID

  DB2FORLUW

• Reported release

  A50

• Status

  CLOSED PER

• PE

  NoPE

• HIPER

  NoHIPER

• Special Attention

  NoSpecatt / Xsystem

• Submitted date

  2015-04-22

• Closed date

  2022-06-20

• Last modified date

  2022-06-20

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

  IT08036

• 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