DB2 - Problem description
Problem IT33573 | Status: Closed |
POOR PERFORMANCE OF FEDERATED QUERIES IN CERTAIN CASES | |
product: | |
DB2 FOR LUW / DB2FORLUW / B10 - DB2 | |
Problem description: | |
The issue is potential for poor performance of federated queries with a predicate which references a column in a single column unique index or constraint due to cardinality over-estimation. For example, using a hash join instead of nested loop join for a query which joins a local table to a federated table with a predicate which references the primary key of the federated table. | |
Problem Summary: | |
**************************************************************** * USERS AFFECTED: * * all * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * fixed in db2_v111m4fp7 * **************************************************************** | |
Local Fix: | |
Solution | |
Workaround | |
**************************************************************** * USERS AFFECTED: * * all * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * fixed in db2_v111m4fp7 * **************************************************************** | |
Comment | |
fixed in db2_v111m4fp7 | |
Timestamps | |
Date - problem reported : Date - problem closed : Date - last modified : | 16.07.2020 05.07.2021 05.07.2021 |
Problem solved at the following versions (IBM BugInfos) | |
Problem solved according to the fixlist(s) of the following version(s) |