DB2 - Problem description
Problem IT09281 | Status: Closed |
OPTIMIZER FAVOURS HSJOIN OVER A BETTER NLJOIN WHEN JOIN COLUMN HAS LESS | |
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 |