DB2 FOR LUW / DB2FORLUW / 970 - DB2

DB2 Query ReWrite may be able to improve the performance of a 
query by optimizing it during compilation if it satisfies the 
following conditions: 
- The query refers to 3 or more UNION ALL views (UAV) 
- Each UAV branch or operand is a select over a base table or 
nickname 
- The UAVs all have the same number of branches or operands 
- The UAVs are all joined to each other 
- The joins between the UAVs are either all inner joins or joins 
on columns that source from row-preserving sides of any outer 
joins 
- At least one join column from each branch or operand of each 
UAV has the same local predicate as corresponding branches from 
other UAVs 
- A one-to-one join mapping can be derived from all of the 
previous conditions 
 
This enhancement is only available under registry variable 
control. To enable it, issue: 
db2set 
DB2_UNION_OPTIMIZATION=[<other-values>,]COMPLEX_DISJOINT_UA_JPPD 
[,<other-values>] 
and restart the database manager for settings to take effect.

**************************************************************** 
* USERS AFFECTED:                                              * 
* NA                                                           * 
**************************************************************** 
* PROBLEM DESCRIPTION:                                         * 
* DB2 Query ReWrite may be able to improve the performance of  * 
* a query by optimizing it during compilation see above for    * 
* condition details                                            * 
**************************************************************** 
* RECOMMENDATION:                                              * 
* Upgrade to DB2 Version 9.7 Fix Pack 4 or manually rewrite    * 
* any applicable queries as explained above.                   * 
****************************************************************

Manually rewrite any applicable queries to be of the form 
derived through this enhancement.

DB2 Version 9.7 Fix Pack 4 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 5 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 6 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 7 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 8 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 9 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 9a for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 10 for Linux, UNIX, and Windows
 

First fixed in DB2 Version 9.7 Fix Pack 4.

keiner bekannt / siehe Local-Fix

Vorgänger  : APAR is sysrouted TO one or more of the following: IC69294 
Nachfolger : 

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

03.06.2010
02.05.2011
02.05.2011

9.7.FP4