Latest versionsfixlist
11.1.0.7 FixList
10.5.0.9 FixList
10.1.0.6 FixList
9.8.0.5 FixList
9.7.0.11 FixList
9.5.0.10 FixList
9.1.0.12 FixList
Have problems? - contact us.
Register for free anmeldung-x26
Contact form kontakt-x26

DB2 - Problem description

Problem IC78830 Status: Closed

CRASH OR WRONG RESULT FOR QUERY CONTAINING LONG STRING IN PREDICATE
"LIKE" IN A MIXED/EUC CODEPAGE.

product:
DB2 FOR LUW / DB2FORLUW / 910 - DB2
Problem description:
If the following conditions are met: 
 
1) A query contains a "like" comparison, where the pattern to 
compare has prefixed characters followed by wildcard such as 
this example: 
select columns from table where pattern like "abc%" 
 
2) The data is in a mixed or EUC codepage 
 
3) The pattern "abc%" has a length that is greater than the 
column data that is being scanned. 
 
Then there exists the possibility that the comparison may do an 
invalid memory access that will crash the instance. In very tiny 
opportunity, a wrong result might return. 
 
If a stack traceback is generated, the function at the top of 
the stack will be an OS memory compare function (differs 
depending on platform, eg. intel_fast_memcmp on Intel platform) 
with sqlv_mixd_short_search() below it.
Problem Summary:
**************************************************************** 
* USERS AFFECTED:                                              * 
* ALL                                                          * 
**************************************************************** 
* PROBLEM DESCRIPTION:                                         * 
* If the following conditions are met:                         * 
*                                                              * 
* 1) A query contains a "like" comparison, where the pattern   * 
* to compare has prefixed characters followed by wildcard such * 
* as this example:                                             * 
*     select columns from table where pattern like "abc%"      * 
*                                                              * 
* 2) The data is in a mixed or EUC codepage                    * 
*                                                              * 
* 3) The pattern "abc%" has a length that is greater than the  * 
* column data that is being scanned.                           * 
*                                                              * 
* Then there exists the possibility that the comparison may do * 
* an invalid memory access that will crash the instance. In    * 
* very tiny opportunity, a wrong result might return.          * 
*                                                              * 
* If a stack traceback is generated, the function at the top   * 
* of the stack will be an OS memory compare function (differs  * 
* depending on platform, eg. intel_fast_memcmp on Intel        * 
* platform) with sqlv_mixd_short_search() below it.            * 
**************************************************************** 
* RECOMMENDATION:                                              * 
* Update to version 9.1 fixpack 11 or later fixpacks.          * 
****************************************************************
Local Fix:
Use shorter string in the LIKE predicate if it is possible.
available fix packs:
DB2 Version 9.1 Fix Pack 11  for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 12  for Linux, UNIX and Windows

Solution
This problem is first fixed in version 9.1 fixpack 11.
Workaround
Use shorter string in the LIKE predicate if it is possible.
Timestamps
Date  - problem reported    :
Date  - problem closed      :
Date  - last modified       :
20.09.2011
29.12.2011
29.12.2011
Problem solved at the following versions (IBM BugInfos)
9.1.FP11
Problem solved according to the fixlist(s) of the following version(s)
9.1.0.11 FixList
This site uses cookies to make it easier for us to provide you with our services. By using our site you agree to the use of cookies.