DB2 FOR LUW / DB2FORLUW / 950 - DB2

DB2 Query ReWrite (QRW) may not completely optimize a query 
containing a nodenumber local predicate on a base table. This 
optimization is only valid if the following conditions are 
satisfied: 
1. There is a pair of Base Tables. 
2. The two Base Tables have the same partitioning map id 
3. The tables have equality join predicate on all the columns of 
the 
partitioning keys of the tables. 
4. Each column of the partitioning key of the first table must 
join to the column of the same order of the partitioning keys of 
the other table 
5. There is a local predicate of the form, 
NODENUMBER(<table>.<col>)=<x> where <x> can be a constant, host 
 
variable, parameter marker or a special register. 
 
Sample Query: 
 
create table T1(c11 int,c12 int,c13 int,c14 int) distribute by 
(c12,c13); 
create table T2(c21 int,c22 int,c23 int,c24 int) distribute by 
(c22,c23); 
 
before fix: 
select * from t1,t2 where nodenumber(t1.c11) = 0 and  t1.c12 = 
t2.c22 and  t1.c13 = t2.c23; 
 
after fix: 
select * from t1,t2 where nodenumber(t1.c11) = 0 and  t1.c12 = 
t2.c22 and  t1.c13 = t2.c23 and nodenumber(t2.<any col>) = 0;

**************************************************************** 
* USERS AFFECTED:                                              * 
* ALL                                                          * 
**************************************************************** 
* PROBLEM DESCRIPTION:                                         * 
* See Problem Description above.                               * 
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* RECOMMENDATION:                                              * 
* Upgrade to Version 9.5 Fix Pack 6.                           * 
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Manually rewrite query with additional local predicate 
nodenumber(<table>.<col>)=<x> on other table.

DB2 Version 9.5 Fix Pack 6a for Linux, UNIX, and Windows
 DB2 Version 9.5 Fix Pack 7 for Linux, UNIX, and Windows
 DB2 Version 9.5 Fix Pack 8 for Linux, UNIX, and Windows
 DB2 Version 9.5 Fix Pack 9 for Linux, UNIX, and Windows
 DB2 Version 9.5 Fix Pack 10 for Linux, UNIX, and Windows
 

First fixed in DB2 Version 9.5 Fix Pack 6.

not known / see Local fix

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

16.09.2009
10.06.2010
10.06.2010

9.5.FP6