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Problem IT37511
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Status: Closed |
POOR PERFORMANCE OF FEDERATED QUERIES IN CERTAIN CASES
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| product: |
DB2 FOR LUW / DB2FORLUW / B50 - 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 |
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| 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 :
| 05.07.2021
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) |
