DB2 FOR LUW / DB2FORLUW / 980 - DB2

To improve performance, when the registry variable DB2_ANTIJOIN 
is set to anything other than NO, DB2 should convert an eligible 
 
OUTER JOIN into an ANTIJOIN. 
To be eligible, all the following must be true: 
 
1. The OUTER JOIN must have an IS NULL predicate on a column 
from the NULL producing side. 
If the column is not the join column then it must be marked NOT 
NULL. 
2. Null producing side of the OUTER JOIN must be a base table 
with no local predicates except for the IS NULL predicate. 
3. It is not a federated query. 
4. The select clause of the query must not reference any column 
from the null producing side of the left outer join. 
 
example: 
select t1.* from t1 left outer join t2 on t1.c1 = t2.c1 where 
t2.c2 IS NULL.

**************************************************************** 
* USERS AFFECTED:                                              * 
* All                                                          * 
**************************************************************** 
* PROBLEM DESCRIPTION:                                         * 
* See problem description                                      * 
**************************************************************** 
* RECOMMENDATION:                                              * 
* Please upgrade to DB2 v9.8 fix pack 4                        * 
****************************************************************

DB2 Version 9.8 Fix Pack 4 for AIX and Linux
 DB2 Version 9.8 Fix Pack 5 for AIX and Linux
 

Fix in DB2 v9.8 fix pack 4

not known / see Local fix

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

06.05.2010
14.02.2011
14.02.2011

9.8.FP4