DB2 FOR LUW / DB2FORLUW / A10 - DB2

Under rare scenarios, DB2 might produce a sub-optimal query plan 
if the following conditions are satisfied: 
1. There are 3 or more inner joined tables in the query (say T1, 
T2, T3) 
2. The query contains a OR predicate with two or more subterms 
consisting of subqueries 
3. The subqueries can be of type Exists, Not Exists or IN 
4. One of the tables (T1) in the inner join is also the source 
for the subquery. 
5. There is only a single join predicate between Table T1 and 
one of the other tables (T2) 
6. (optional) There may be  local predicates on tables not 
directly connect to T1. 
 
eg. select * from t1, t2, t3 where 
t1.c1 = t2.c1 and t2.c2 = t3.c2 and t3.c1 = 1 and 
exists (select c1 from T4 where t1.c2 = t4.c2) or 
exists (select c1 from T5 where t1.c2 = t5.c2);

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* USERS AFFECTED:                                              * 
* All                                                          * 
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* PROBLEM DESCRIPTION:                                         * 
* See Error Description                                        * 
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* RECOMMENDATION:                                              * 
* Upgrade to  DB2 version 101 fixpack 3                        * 
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db2set -im DB2COMPOPT=327685,524288

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
 

The problem is fixed in DB2 version 101 fixpack 3

not known / see Local fix

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

24.07.2013
24.10.2013
24.10.2013