DB2 FOR LUW / DB2FORLUW / 970 - DB2

A LIKE predicate with an escape-expression does not use an 
available index when the match-expression is a GRAPHIC or 
VARGRAPHIC column, and both the pattern-expression and 
escape-expression are CHAR or VARCHAR type.  For example: 
 
   ... WHERE graphiccol LIKE 'abc!_%' ESCAPE '!' 
 
Any index on column graphiccol will not be exploited possibly 
resulting in poor query performance.  This only applies to a 
unicode database, since mixing of graphic and non-graphic types 
is not allowed otherwise.

**************************************************************** 
* USERS AFFECTED:                                              * 
* ALL                                                          * 
**************************************************************** 
* PROBLEM DESCRIPTION:                                         * 
* Internally we treat LIKE just as any other function call, we * 
* follow the function resolution rules to find the best fit    * 
* function.  We have four (internal) versions of LIKE:         * 
*                                                              * 
* LIKE(VC,VC)                                                  * 
* LIKE(VC,VC,VC)                                               * 
* LIKE(VG,VG)                                                  * 
* LIKE(VG,VG,VG)                                               * 
*                                                              * 
* Following the documented function resolution rules, we map   * 
* these calls as follows:                                      * 
*                                                              * 
* VG LIKE VC -> LIKE( VG, VARGRAPH(VC) ) best fit is           * 
* LIKE(VG,VG)                                                  * 
* VG LIKE VC ESCAPE VC -> LIKE( VARCHAR(VG), VC, VC ) this is  * 
* the best fit as there is only one cast                       * 
*                                                              * 
* The behaviour makes sense if we think of LIKE as a function  * 
* call. This APAR will try to avoid a cast on the first        * 
* argument since that is the only argument that can reference  * 
* a column, and hence a cast will hide the column index.       * 
**************************************************************** 
* RECOMMENDATION:                                              * 
* Upgrade to DB2 Version 9.7 and Fix Pack 4                    * 
****************************************************************

Cast the pattern-expression and/or escape-expression to graphic 
type.  For constants, a G prefix can be added: 
 
   ... WHERE graphiccol LIKE G'abc!_%' ESCAPE G'!'

DB2 Version 9.7 Fix Pack 4 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 5 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 6 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 7 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 8 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 9 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 9a for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 10 for Linux, UNIX, and Windows
 

Problem was first fixed in DB2 Version 9.7 and Fix Pack 4

keiner bekannt / siehe Local-Fix

Datum - Problem gemeldet    :
Datum - Problem geschlossen :
Datum - der letzten Änderung:

16.11.2010
28.04.2011
28.04.2011

9.7.