DB2 FOR LUW / DB2FORLUW / A50 - DB2

Users might observe performance regression when upgrading from 
V9.7 and running queries with the following characteristics: 
1. Queries contain NOT EXISTS or NOT IN predicates 
2. Sub-queries in the NOT EXISTS or NOT IN predicates contain 
correlated sub-queries 
3. The correlation sources of these correlated sub-queries are 
local to the NOT EXISTS or NOT IN sub-queries 
 
An example of such a query is: 
 
select p1 
from   p 
where not exists 
(select * 
-- This NOT EXISTS sub-query contains correlated sub-queries 
from (select * 
       from a 
      where exists (select 1                              -- 
This correlated sub-query has correlation source from Table A 
which is local to the NOT EXISTS sub-query 
                           from b 
                           where b1=a1 order by b1) 
      fetch first 1 row only) q 
where q.a2 = p.p1)

**************************************************************** 
* USERS AFFECTED:                                              * 
* ALL                                                          * 
**************************************************************** 
* PROBLEM DESCRIPTION:                                         * 
* See Error Description                                        * 
**************************************************************** 
* RECOMMENDATION:                                              * 
* Upgrade to Db2 10.5 Fix Pack 9 or higher                     * 
****************************************************************

First fixed in Db2 10.5 Fix Pack 9

not known / see Local fix

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

18.05.2017
29.09.2017
08.01.2018

9.0.