A fix is available
APAR status
Closed as program error.
Error description
On a system with INTRA_PARALLEL enabled, the execution of a query that requires a sort (for example, due to a SELECT DISTINCT, ORDER BY, or aggregation operator) may cause the database to abend. A message similar to the following will be seen in the db2diag.log . 2007-09-08-08.43.55.642903-240 I23338A2173 LEVEL: Severe PID : 11111 TID : 1 PROC : db2agntp (xxxxxxx) 0 INSTANCE: xxxxxxxx NODE : 000 APPHDL : 0-484 APPID: 112.32.74.52.39558.070905064434 AUTHID : XXXXXXX FUNCTION: DB2 UDB, buffer pool services, sqlbufix, probe:155 DATA #1 : String, 40 bytes sqlbufix : Page and Object do not Match! . The mismatch is between the page header information, which will appear in the diag log similar to this: . DATA #2 : Page header, PD_TYPE_SQLB_PAGE_HEAD, 48 bytes pageHead: {pool:4;obj:11;type:128} PPNum:1 OPNum:1 . and the buffer page descriptor, which will appear in the diag log similar to this: . DATA #3 : Buffer page descriptor, PD_TYPE_SQLB_BPD, 152 bytes Pagekey: {pool:4;obj:0;type:128} PPNum:1 . The most important pieces of information are that the page type is a temporary page (type is 128) and that the object ID is set to 0 in the BPD. . The stack will show function sqlbufix and lower in the stack you will see sort functions such as sqlsmergerec.
Local fix
The problem can be worked around by disabling INTRA_PARALLEL.
Problem summary
Users affected: all users of INTRA_PARALLEL Problem description: During execution of a query that uses a sort, the database may crash and the db2diag.log will show an error from sqlbufix probe 155. Problem summary: With INTRA_PARALLEL enabled, it is possible that a temporary page may be freed twice by different subagents, resulting in the crash. This APAR fixes the problem by serializing access to the temp page.
Problem conclusion
First fixed in DB2 UDB Version 8, Fix Pack 16.
Temporary fix
Problem can be avoided by disabling INTRA_PARALLEL
Comments
APAR Information
APAR number
IZ05977
Reported component name
DB2 UDB ESE SOL
Reported component ID
5765F4102
Reported release
810
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2007-10-04
Closed date
2008-02-07
Last modified date
2008-02-07
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Modules/Macros
ENGN_SQS
Fix information
Fixed component name
DB2 UDB ESE SOL
Fixed component ID
5765F4102
Applicable component levels
R810 PSN
UP
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Document Information
Modified date:
07 February 2008