DB2 FOR LUW / DB2FORLUW / A50 - DB2

Db2 may produce wrong result when the following conditions are
met:
1) The query has an equality predicate
2) The equality predicate has a constant string in one side and
   a constant concatenated with a fixed length character column
on the other side
3) The number of characters in the constant part of
concatenation is less than the
   number of characters in the constant used in the other side
of the predicate.
4) SYSIBM.NLS_STRING_UNITS is set to 'CODEUNITS32'

Example:
CREATE TABLE T (C CHAR(4 CODEUNITS32) NOT NULL);
insert into T values('BCD');
select * from T where 'ABCD'='A'||C;

The expected result is 1 row :
C
----------------
BCD

  1 record(s) selected.

and it generates 0 rows, which is wrong.

****************************************************************
* USERS AFFECTED:                                              *
* All DB2 LUW Users                                            *
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* PROBLEM DESCRIPTION:                                         *
* See Error Description                                        *
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* RECOMMENDATION:                                              *
* Upgrade to DB2 10.5 Fix Pack 10 or later.                    *
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Rewrite the query by splitting the predicate so that
concatenation gets removed:

select * from T where 'A'='A' and 'BCD'=C;

or rewrite to remove the constant part of the predicate as:
select * from T where 'BCD'=C;

not known / see Local fix

forerunner  : 
follow-up : IT22826 

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

18.10.2017
12.07.2018
12.07.2018