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DB2 - Problem description

Problem IC63226 Status: Closed

DB2 QUERY REWRITE MAY NOT COMPLETELY OPTIMIZE A QUERY CONTAINING NODENUMBER
LOCAL PREDICATE

product:
DB2 FOR LUW / DB2FORLUW / 910 - DB2
Problem description:
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;
Problem Summary:
**************************************************************** 
* USERS AFFECTED:                                              * 
* All users using DB2 in MPP environment                       * 
**************************************************************** 
* PROBLEM DESCRIPTION:                                         * 
* Please see Problem Description above.                        * 
**************************************************************** 
* RECOMMENDATION:                                              * 
* Upgrade to DB2 Version 9.1 Fix Pack 10                       * 
****************************************************************
Local Fix:
Manually rewrite query with additional local predicate 
nodenumber(<table>.<col>)=<x> on other table.
available fix packs:
DB2 Version 9.1 Fix Pack 10  for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 11  for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 12  for Linux, UNIX and Windows

Solution
First fixed in DB2 Version 9.1 Fix Pack 10
Workaround
not known / see Local fix
Comment
Fix is available in DB2 V9.1 fix pack 10
BUG-Tracking
forerunner  : APAR is sysrouted TO one or more of the following: IC63227 IC63229 IC70344 
follow-up : 
Timestamps
Date  - problem reported    :
Date  - problem closed      :
Date  - last modified       :
16.09.2009
20.06.2011
20.06.2011
Problem solved at the following versions (IBM BugInfos)
9.1.FP10
Problem solved according to the fixlist(s) of the following version(s)
9.1.0.10 FixList