IT31146: ANTIJOIN BLOCKED WHEN QUERY HAS SIDE EFFECTS

Db2 Version 11.1 Mod 4 Fix Pack 6 for Linux, UNIX, and Windows
Db2 Version 11.1 Mod 4 Fix Pack 6 for Linux, UNIX, and Windows

APAR status

• Closed as program error.

Error description

• Db2 query may show poor performance since antijoin is not formed
  due to presence of side effect in the query, although the side
  effect is not dependent on the query block that can be
  considered for antijoin.
  

Local fix

• Add select * on the subquery having not exists and also add
  order by to the end of that added select. In column store along
  with that, use registry setting DB2COMPOPT=NO_OBELIM
  

Problem summary

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  * USERS AFFECTED:                                              *
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  * PROBLEM DESCRIPTION:                                         *
  * See Error Description                                        *
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  * RECOMMENDATION:                                              *
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Problem conclusion

Temporary fix

Comments

APAR Information

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

  IT31138

• 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 PSY

     UP