|
Problem IT09281
|
Status: Closed |
OPTIMIZER FAVOURS HSJOIN OVER A BETTER NLJOIN WHEN JOIN COLUMN HAS LESS THAN 3 DISTINCT VALUES |
| product: |
DB2 FOR LUW / DB2FORLUW / 970 - DB2 |
| Problem description: |
The optimizer might favour a HSJOIN over a better performing
NLJOIN if there are one or more equality join preds where the
join column on the outer input of the NLJOIN has less than 3
distinct values and the other has a large number of distinct
values. |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* All *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Error Description *
****************************************************************
* RECOMMENDATION: *
* Upgrade to inclusive fixpack. *
**************************************************************** |
| Local Fix: |
You can apply an optimization profile to request the optimizer
to choose a NLJOIN |
| Solution |
|
| Workaround |
not known / see Local fix |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 04.06.2015
07.10.2015
07.10.2015 |
| Problem solved at the following versions (IBM BugInfos) |
|
| Problem solved according to the fixlist(s) of the following version(s) |
| 9.7.0.11
|
 |
