DB2 FOR LUW / DB2FORLUW / 950 - DB2

During SQL/XQuery compilation, a very large and complex 
predicate in the query being compiled may cause the DB2 
instance to abend due to a stack overflow exception. Although 
new  behaviour in DB2 Version 9.5 should ideally cause 
the DB2 agent to dump an sqlcode SQL0973N upon detecting such a 
scenario, this may not happen when a very large predicate, 
e.g., deeply nested series of ORs, etc., is present in the 
query. 
The stack trace from such an abend will look something like: 
 
sqlnr_in2or_cond_traverse <repeated 60,000 or more times> 
sqlnr_sinlist2or 
sqlnr_optprep 
sqlnr_optprep_action 
sqlnr_comp 
 
Note that the number 60,000 mentioned above 
is from scenarios observed with default database 
configuration values.

**************************************************************** 
* USERS AFFECTED:                                              * 
* All Platforms                                                * 
**************************************************************** 
* PROBLEM DESCRIPTION:                                         * 
* During SQL/XQuery compilation, a very large and              * 
* complexpredicate in the query being compiled may cause the   * 
* DB2instance to abend due to a stack overflow                 * 
* exception.Althoughnew  behaviour in DB2 Version 9.5 should   * 
* ideally causethe DB2 agent to dump an sqlcode SQL0973N upon  * 
* detectingsuch ascenario, this may not happen when a very     * 
* large predicate,e.g., deeply nested series of ORs, etc., is  * 
* present in thequery.The stack trace from such an abend will  * 
* look something like:sqlnr_in2or_cond_traverse <repeated      * 
* 60,000 or more                                               * 
* times>sqlnr_sinlist2orsqlnr_optprepsqlnr_optprep_actionsqlnr_c 
* that the number 60,000 mentioned aboveis from scenarios      * 
* observed with default databaseconfiguration values.          * 
**************************************************************** 
* RECOMMENDATION:                                              * 
* Upgrade to Db2 v9.5 Fixpak 7 or higher                       * 
****************************************************************

In DB2 Version 9.5, users have the ability to control the size 
of the runtime stack used by a DB2 agent. Consequently, 
increasing 
the value for the "agent_stack_sz" database configuration 
parameter will help workaround the issue.

DB2 Version 9.5 Fix Pack 7 for Linux, UNIX, and Windows
 DB2 Version 9.5 Fix Pack 8 for Linux, UNIX, and Windows
 DB2 Version 9.5 Fix Pack 9 for Linux, UNIX, and Windows
 DB2 Version 9.5 Fix Pack 10 for Linux, UNIX, and Windows
 

First Fixed in DB2 v9.5 Fixpak 7

not known / see Local fix

forerunner  : APAR is sysrouted TO one or more of the following: IC69330 IC69331 
follow-up : 

Date  - problem reported    :
Date  - problem closed      :
Date  - last modified       :

17.06.2010
15.11.2010
15.11.2010

9.5.