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Problem IC91303
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Status: Closed |
REMOVE REDUNDANT SUBTERM PREDICATE FROM AN OR PREDICATE |
| product: |
DB2 FOR LUW / DB2FORLUW / A10 - DB2 |
| Problem description: |
An OR(disjunct) predicate has multiple subterm predicates,
called SP1, SP2, and so on. Each OR subterm predicate SP is
either a simple predicate or multiple predicates combined with
AND (conjunct). Given two subterm predicates, SPi and SPj, if
SPi is identical to SPj or SPi is identical to any conjunct
predicate under SPj, SPj has no filtering effect and will be
removed from the parent OR predicate.
As example:
select * from table where ( ( col1 = 1 ) or ( col1 = 2 ) ) or (
( col2 = 1 ) and ( col1 = 2 ) )
P1: ( col1 = 1 ) or
P2: ( col1 = 2 ) ) or
P3: ( ( col2 = 1 ) and ( col1 = 2 ))
Predicate P3 is redundant - it is true only if P2 is true, thus
can be safely removed during query rewrite phase |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* ALL *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Error Description *
****************************************************************
* RECOMMENDATION: *
* Upgrade to DB2 Version 10.1 Fix Pack 3 *
**************************************************************** |
| Local Fix: |
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| available fix packs: |
DB2 Version 10.1 Fix Pack 3 for Linux, UNIX, and Windows
DB2 Version 10.1 Fix Pack 4 for Linux, UNIX, and Windows
DB2 Version 10.1 Fix Pack 3a for Linux, UNIX, and Windows
DB2 Version 10.1 Fix Pack 6 for Linux, UNIX, and Windows
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| Solution |
|
| Workaround |
not known / see Local fix |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 03.04.2013
17.10.2013
17.10.2013 |
| Problem solved at the following versions (IBM BugInfos) |
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| Problem solved according to the fixlist(s) of the following version(s) |
| 10.1.0.3
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| 10.1.0.3
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