DB2 FOR LUW / DB2FORLUW / 980 - 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:                                         * 
* DB2 instance may abend due to stack overflow (instead of     * 
* dumping                                                      * 
* SQL0973N) while processing a very large predicate            * 
**************************************************************** 
* RECOMMENDATION:                                              * 
* Upgrade to v9.8 Fixpack 4                                    * 
****************************************************************

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 9.8 Fix Pack 4 for AIX and Linux
 DB2 Version 9.8 Fix Pack 5 for AIX and Linux
 

First fixed in v9.8 Fixpack 4

not known / see Local fix

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

18.06.2010
04.08.2011
04.08.2011

9.8.FP4