|
Problem IC62213
|
Status: Closed |
THE SQL QUERY OPTIMIZER MAY ADD AN UNNECESSARY TABLE QUEUE OPERATION UNDER CERTAIN CONDITIONS |
| product: |
DB2 FOR LUW / DB2FORLUW / 950 - DB2 |
| Problem description: |
In a DPF environment, the optimizer may choose to perform an
unnecessary table queue operation which may lead to a
non-optimal query execution plan. This can occur if a table
that is hash partitioned across multiple database partitions is
referenced in a statement with multiple joins, and the table's
partitioning key is not of interest to the query. For example,
the partitioning key is not part of any join, nor a group by or
order by clause. |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* ALL *
****************************************************************
* PROBLEM DESCRIPTION: *
* In a DPF environment, the optimizer may choose to perform an *
* unnecessary table queue operation which may lead to a *
* non-optimal query execution plan. This can occur if a table *
* that is hash partitioned across multiple database partitions *
* is referenced in a statement with multiple joins, and the *
* table's *
* partitioning key is not of interest to the query. For *
* example, the partitioning key is not part of any join, nor a *
* group by or order by clause. *
****************************************************************
* RECOMMENDATION: *
* Upgrade To DB2 Version 9.5 Fix Pack 6 *
**************************************************************** |
| Local Fix: |
|
| 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 Fix Pack 6 |
| Workaround |
not known / see Local fix |
| BUG-Tracking |
forerunner : APAR is sysrouted TO one or more of the following: IC62473 IC62474 IC62475 IC68455
follow-up : |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 24.07.2009
14.10.2010
14.10.2010 |
| Problem solved at the following versions (IBM BugInfos) |
9.5.FP6
|
| Problem solved according to the fixlist(s) of the following version(s) |
