DB2 FOR LUW / DB2FORLUW / A50 - DB2

You may observe degraded performance if following conditions are 
met: 
 
1. DB2_COMPATIBILITY_VECTOR is set to one of the valid value 
(like ORA, SYB etc). 
2. It has to be column organized table. 
3. We are comparing different datatypes in WHERE clause. 
 
Testcase: 
 
db2stop 
db2set DB2_COMPATIBILITY_VECTOR=ORA 
db2 update dbm cfg using intra_parallel YES 
db2start 
CREATE TABLE tab1 (HASH_DIFF CHARACTER(32) NOT NULL, HASH_KEY 
CHARACTER(32))ORGANIZE BY COLUMN; 
CREATE OR REPLACE VARIABLE parav VARCHAR(32); 
CREATE OR REPLACE VARIABLE parac CHAR(32); 
CREATE OR REPLACE VARIABLE param2 CHAR(32); 
SET parav = '000723afab3fa1cf475a61789e85ba76'; 
SET parac = '000723afab3fa1cf475a61789e85ba76'; 
SET param2 = '5d34a29f43bdfeaed314d51031cfb7f0'; 
-- Following UPDATE will run slower 
UPDATE tab1 SET HASH_DIFF=param2 WHERE HASH_KEY=CAST(parav AS 
CHAR(32)); 
-- Following UPDATE will run faster 
UPDATE tab1 SET HASH_DIFF=param2 WHERE HASH_KEY=CAST(parac AS 
CHAR(32));

**************************************************************** 
* USERS AFFECTED:                                              * 
* All BLU Users prior to DB2 v10.5 FP7                         * 
**************************************************************** 
* PROBLEM DESCRIPTION:                                         * 
* See Error Description                                        * 
**************************************************************** 
* RECOMMENDATION:                                              * 
* Please upgrade to DB2 v10.5 FP7.                             * 
****************************************************************

If possible, please specify same datatype while comparing data 
in WHERE clause.

Problem is first fixed in DB2 v10.5 FP7.

not known / see Local fix

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

18.04.2015
20.01.2016
20.01.2016