DB2 - Problembeschreibung
Problem IT08407 | Status: Geschlossen |
PEFORMANCE IS DEGRADED WITH BLU WHILE COMPARING CHAR with VARCHAR IN WHERE CLAUSE IF DB2_COMPATIBILITY_VECTOR IS SET. | |
Produkt: | |
DB2 FOR LUW / DB2FORLUW / A50 - DB2 | |
Problembeschreibung: | |
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)); | |
Problem-Zusammenfassung: | |
**************************************************************** * USERS AFFECTED: * * All BLU Users prior to DB2 v10.5 FP7 * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Please upgrade to DB2 v10.5 FP7. * **************************************************************** | |
Local-Fix: | |
If possible, please specify same datatype while comparing data in WHERE clause. | |
Lösung | |
Problem is first fixed in DB2 v10.5 FP7. | |
Workaround | |
keiner bekannt / siehe Local-Fix | |
Weitere Daten | |
Datum - Problem gemeldet : Datum - Problem geschlossen : Datum - der letzten Änderung: | 18.04.2015 20.01.2016 20.01.2016 |
Problem behoben ab folgender Versionen (IBM BugInfos) | |
Problem behoben lt. FixList in der Version | |
10.5.0.7 |