DB2 FOR LUW / DB2FORLUW / A50 - DB2

DB2 should remove single-level correlation of redundant 
predicates within queries. 
 
Example: 
 
SELECT t1.c1 FROM t1 
WHERE t1.c1 IS NULL AND 
EXISTS 
(SELECT 1 FROM t2 
WHERE t1.c1 IS NULL) 
 
This query has a redundant correlated predicate (t1.c1 IS NULL). 
DB2 should eliminate the duplicate predicate as follows: 
 
SELECT t1.c1 FROM t1 
WHERE t1.c1 IS NULL AND 
EXISTS 
(SELECT 1 FROM t2)

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* USERS AFFECTED:                                              * 
* ALL                                                          * 
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* PROBLEM DESCRIPTION:                                         * 
* See Error Description                                        * 
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* RECOMMENDATION:                                              * 
* Update to DB2 Version 10.5 Fix Pack 7.                       * 
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Avoid writing queries containing redundant correlated 
predicates.

This problem is first fixed in DB2 Version 10.5 Fix Pack 7.

not known / see Local fix

Date  - problem reported    :
Date  - problem closed      :
Date  - last modified       :

18.08.2015
20.01.2016
20.01.2016