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Problem IC69330
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Status: Closed |
DB2 instance may abend due to stack overflow (instead of dumping SQL0973N) while processing a very large predicate |
| product: |
DB2 FOR LUW / DB2FORLUW / 970 - DB2 |
| Problem description: |
During SQL/XQuery compilation, a very large and complex
expression 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 expression,
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 thousands of times>
sqlnr_sinlist2or
sqlnr_optprep
sqlnr_optprep_action
sqlnr_comp
or
sqlnr_pullup_trans_pid <repeated thousands of times>
sqlnr_compensate_prd
sqlnr_subsume_prds
sqlnr_subsume_derived_match
sqlnr_subsume_match
sqlnr_compute_matchinfo
sqlnr_optprep |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* ALL *
****************************************************************
* PROBLEM DESCRIPTION: *
* During SQL/XQuery compilation, a very large and *
* complexexpression 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 expression,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 *
* thousands of *
* times>sqlnr_sinlist2orsqlnr_optprepsqlnr_optprep_actionsqlnr_c
* <repeated thousands of *
* times>sqlnr_compensate_prdsqlnr_subsume_prdssqlnr_subsume_deri
****************************************************************
* RECOMMENDATION: *
* Look to Upgrade to a Version 9.7 Fix Pack 3 or later *
**************************************************************** |
| Local Fix: |
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 may help workaround the issue. |
| available fix packs: |
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 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
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| Solution |
Problem was first fixed in Version 9.7 Fix Pack 3 |
| Workaround |
not known / see Local fix |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 18.06.2010
27.09.2010
27.09.2010 |
| Problem solved at the following versions (IBM BugInfos) |
9.7.FP3
|
| Problem solved according to the fixlist(s) of the following version(s) |
| 9.7.0.3
|
 |
| 9.7.0.3
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