|
Problem IC66440
|
Status: Closed |
STATEMENT COMPILATION MAY FAIL TO USE THE STATISTICS COLLECTED FOR A GLOBAL TEMPORARY TABLE. |
| product: |
DB2 FOR LUW / DB2FORLUW / 950 - DB2 |
| Problem description: |
In some situations, statement compilation may fail to use the
statistics collected for a global temporary table. This may
lead to a non optimal access plan. For example, in the sequence
of:
1. declare global temporary table
2. insert data into the global temporary table
3. runstats on the global temporary
4. use the global temporary table in a query
the statement compilation in step4 may not use the statistics
collected in step3. |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* All *
****************************************************************
* PROBLEM DESCRIPTION: *
* In some situations, statement compilation may fail to *
* usethestatistics collected for a global temporary table. *
* This maylead to a non optimal access plan. For example, in *
* thesequenceof:1. declare global temporary table2. insert *
* data into the global temporary table3. runstats on the *
* global temporary4. use the global temporary table in a *
* querythe statement compilation in step4 may not use *
* thestatisticscollected in step3. *
****************************************************************
* RECOMMENDATION: *
* Upgrade to DB2 version 9.5 FP6 *
**************************************************************** |
| Local Fix: |
- After observing the problem, repeating the RUNSTATS operation
typically clears the problem.
- Querying the global temporary table prior to the RUNSTATS
operation, for example with "select 1 from session.t1 fetch
first 1 row only", typically avoids the problem. |
| available fix packs: |
DB2 Version 9.5 Fix Pack 6a for Linux, UNIX, and Windows
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
|
| Solution |
First fixed in DB2 version 9.5 FP6 |
| Workaround |
not known / see Local fix |
| BUG-Tracking |
forerunner : APAR is sysrouted TO one or more of the following: IC66441 IC66442 IC66443
follow-up : |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 18.02.2010
14.06.2010
14.06.2010 |
| Problem solved at the following versions (IBM BugInfos) |
9.5.FP6
|
| Problem solved according to the fixlist(s) of the following version(s) |
