DB2 FOR LUW / DB2FORLUW / 970 - DB2

The Query Rewrite component of the DB2 Query compiler will 
perform a cost based evaluation to see whether pushing down an 
inner join into a left outer join 
is beneficial for query performance. Due to a problem introduced 
by the fix of APAR IC83902, V9.7 Fix Pack 9 may wrongly 
calculate this cost and hence make the wrong decision. 
This may lead to performance regression of some statements in 
V9.7 Fix Pack 9 compared to earlier Fix Pack releases. 
 
You may be able to identify this issue by comparing the 
"Optimized Statement" section in the db2exfmt output of a 
statement with the same generated on an earlier Fix Pack.

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* USERS AFFECTED:                                              * 
* All                                                          * 
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* PROBLEM DESCRIPTION:                                         * 
* See Error Description                                        * 
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* RECOMMENDATION:                                              * 
* Upgrade to DB2 Version 9.7 Fix Pack 10                       * 
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Setting : 
db2set DB2COMPOPT=327685,268435456 
and restarting the DB2 instance, will disable the fix for APARr 
IC83902. 
 
However as it also disables the fix for APAR 
http://www-01.ibm.com/support/docview.wss?uid=swg1IC79170 
the workaround should be used with caution.

First fixed in DB2 Version 9.7 Fix Pack 10

keiner bekannt / siehe Local-Fix

Datum - Problem gemeldet    :
Datum - Problem geschlossen :
Datum - der letzten Änderung:

27.02.2014
11.11.2014
11.11.2014

9.7.FP10