DB2 FOR LUW / DB2FORLUW / A10 - DB2

Equality join predicates may be pushed down thru an OLAP 
function. 
The columns in the join predicates are required to be a superset 
of a unique index (or a primary key). The join predicates then 
will 
form a correlation, resulting in limiting the only join method 
eligible 
be the NLJOIN. This could cause a performance degradation. 
 
An indicator that a user has hit this problem is to look at the 
Optimized Statement of the db2exfmt output. 
 
   (SELECT ..., <func>(<col> OVER (PARTITION NY <col>,...), ... 
    FROM  Q#3, ... 
    WHERE Q#3.<col> = Q#2.<col> 
    ) AS Q#1, 
    <table> AS Q#2, ... 
 
If a correlated join predicate such as Q#3.<col> = Q#2.<col> is 
seen, 
this SQL statement may hit this problem.

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* USERS AFFECTED:                                              * 
* DB2 UDB Version 10.1                                         * 
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* PROBLEM DESCRIPTION:                                         * 
* See Error Description                                        * 
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* RECOMMENDATION:                                              * 
* Upgrade to Version 10.1 FixPack 1.                           * 
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DB2 Version 10.1 Fix Pack 1 for Linux, UNIX, and Windows
 DB2 Version 10.1 Fix Pack 2 for Linux, UNIX, and Windows
 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
 

Problem was first fixed in DB2 UDB Version 10.1 FixPack 1.

not known / see Local fix

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

14.06.2012
03.11.2012
03.11.2012