|
Problem IC77848
|
Status: Closed |
DB2 MAY ABEND WHILE OPTIMIZER IS FORCED TO CHOOSE REPLICATED MQT IN DPF |
| product: |
DB2 FOR LUW / DB2FORLUW / 970 - DB2 |
| Problem description: |
When a query is matched to a set of MQTs, optimizer will
determine which MQT to use in the access plan based on costing.
User can override the costing decision and force optimizer to
choose replicated MQT via registry control flag
"FORCE_REPLICATED_MQT_MERGE". Under that setting, query
compilation may crash with call StackTrace having pattern:
sqlnq_qurqtbchild2pp
...
sqlnr_exe
To hit the problem, the following conditions should all be
satisfied:
o Registry variable "DB2_EXTENDED_OPTIMIZATION" setting
includes flag "FORCE_REPLICATED_MQT_MERGE".
o It is a DPF system.
o In addition to REPLICATED MQT, there are non-REPLICATED MQT
online as well.
o The compiled query should contain "SELECT DISTINCT"
operator, or "EXISTS" predicate, or "IN" predicate whose
right operand is a subquery. |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* All *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Error Description above. *
****************************************************************
* RECOMMENDATION: *
* Upgrade to DB2 9.7 Fix Pack 5 or higher *
**************************************************************** |
| Local Fix: |
Reset REPLICATED MQT enforcement. |
| available fix packs: |
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
|
| Solution |
First Fixed in DB2 Version 9.7 Fix Pack 5 |
| Workaround |
not known / see Local fix |
| BUG-Tracking |
forerunner : APAR is sysrouted TO one or more of the following: IC82501
follow-up : |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 29.07.2011
12.03.2012
12.03.2012 |
| Problem solved at the following versions (IBM BugInfos) |
9.7.FP5
|
| Problem solved according to the fixlist(s) of the following version(s) |
| 9.7.0.5
|
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