DB2 FOR LUW / DB2FORLUW / 970 - DB2

If you issue a query with an IN-list predicate and apply a 
statement-level optimization guideline to the query, and if the 
chosen access plan has a star join index-ANDing access with the 
IN-list predicate applied in one of the star join semi-join 
subplans, then the optimizer might not choose an in-to-join 
access for applying the IN-list predicate even if that would 
have been the optimal choice. As a result, the query might not 
perform as well as expected. 
 
This might occur whether or not the optimization guideline 
itself includes a join request for the in-to-join access or a 
star join index ANDing access request. 
 
You might or might not receive an SQL0437W warning sqlcode 
("Performance of this complex query may be sub-optimal.") with 
reason code 13 when this occurs. 
 
Since the Access Plan Reuse feature makes use of optimization 
guideline functionality, this might also result in Access Plan 
Reuse not being fully successful. If this occurs you will 
receive an SQL20516W warning sqlcode ("The statement compilation 
was successful but the access plan for this statement could not 
be preserved.") with reason code 107.

**************************************************************** 
* USERS AFFECTED:                                              * 
* ALL                                                          * 
**************************************************************** 
* PROBLEM DESCRIPTION:                                         * 
* Under some circumstances the query optimizer will fail to    * 
* consider in-to-join access plans for applying IN-list        * 
* predicates within a star join index-ANDing semijoin subplan  * 
* when a statement-level optimization guideline is present. As * 
* a result, the generated access plan may be suboptimal.       * 
*                                                              * 
* You might or might not receive an SQL0437W warning sqlcode   * 
* ("Performance of this complex query may be sub-optimal.")    * 
* with reason code 13 when this occurs.                        * 
*                                                              * 
*                                                              * 
*                                                              * 
* Since the Access Plan Reuse feature makes use of             * 
* optimization guideline functionality, this might also result * 
* in Access Plan Reuse not being fully successful. If this     * 
* occurs you will receive an SQL20516W warning sqlcode ("The   * 
* statement compilation was successful but the access plan for * 
* this statement could not be preserved.") with reason code    * 
* 107.                                                         * 
**************************************************************** 
* RECOMMENDATION:                                              * 
* Upgrade to Version 9.7 Fix Pack 2.                           * 
****************************************************************

DB2 Version 9.7 Fix Pack 2 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 3 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 3a for Linux, UNIX, and Windows
 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 9a 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 10 for Linux, UNIX, and Windows
 

Problem was first fixed in Version 9.7 Fix Pack 2. The fix is to 
be applied to the database server.

keiner bekannt / siehe Local-Fix

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

18.12.2009
14.05.2010
14.05.2010

9.7.FP2