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Problem IT34242
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Status: Closed |
BAD PERFORMANCE DUE TO DELAYED JOIN PREDICATE PUSHDOWN THROUGH UNION ALL PREVENTS JOIN ELIMINATION
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| product: |
DB2 FOR LUW / DB2FORLUW / B50 - DB2 |
| Problem description: |
Db2 query may perform slowly when the following conditions are
met:
-The query has multiple joins.
-One or more joins are on UNIONs on large number of tables.
-There are check constraints defined on the tables used with
UNION.
-There are one or more predicates that may filter out one or
more tables from the UNIONs. |
| Problem Summary: |
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* USERS AFFECTED: *
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* PROBLEM DESCRIPTION: *
* See Error Description *
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* RECOMMENDATION: *
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| Local Fix: |
|
| Solution |
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| Workaround |
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* USERS AFFECTED: *
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* PROBLEM DESCRIPTION: *
* See Error Description *
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* RECOMMENDATION: *
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| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 16.09.2020
24.03.2021
24.03.2021 |
| Problem solved at the following versions (IBM BugInfos) |
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| Problem solved according to the fixlist(s) of the following version(s) |
