|
Problem IT21033
|
Status: Closed |
COST OVER-ESTIMATE OF THE REFETCH DURING UPDATE/DELETE/MERGE OPERATION |
| product: |
DB2 FOR LUW / DB2FORLUW / B10 - DB2 |
| Problem description: |
During SQL statements with UPDATE and DELETE operations
(including MERGE) the optimizer can over-estimate the cost of
the reFETCH which can lead to choosing a plan using NLJN below
the UPDATE/DELETE instead of a HSJN.
The HSJN itself is correctly costed lower than the NLJOIN, but
the issue is with the cost of the reFETCH operator below the
UPDATE. |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* ALL *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Error Description *
****************************************************************
* RECOMMENDATION: *
* Upgrade to Db2 Version 11.1 Mod 3 FixPack 3 *
**************************************************************** |
| Local Fix: |
|
| available fix packs: |
Db2 Version 11.1 Mod 3 Fix Pack 3 for Linux, UNIX, and Windows
Db2 Version 11.1 Mod3 Fix Pack3 iFix001 for Linux, UNIX, and Windows
Db2 Version 11.1 Mod3 Fix Pack3 iFix002 for Linux, UNIX, and Windows
|
| Solution |
First fixed in Db2 Version 11.1 Mod 3 FixPack 3 |
| Workaround |
not known / see Local fix |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 14.06.2017
19.03.2018
19.03.2018 |
| Problem solved at the following versions (IBM BugInfos) |
|
| Problem solved according to the fixlist(s) of the following version(s) |
