DB2 - Problembeschreibung
| Problem IC98655 | Status: Geschlossen |
SUBQUERIES REFERENCING AN ALWAYS FALSE PREDICATE MIGHT NOTICE BAD PERFORMANCE | |
| Produkt: | |
DB2 FOR LUW / DB2FORLUW / A10 - DB2 | |
| Problembeschreibung: | |
Under rare scenarios, a query executing on DB2 might take a long
time if the following conditions are true:
1) The query contains one or more subqueries of the type NOT
EXISTS/NOT IN.
2) The subqueries contains predicates which can be proven to be
ALWAYS FALSE and
produce an empty result set.
eg. Select * from T1
Where Not Exists (select * from T2
where T1.c1 = T2.c1 and
1=0) | |
| Problem-Zusammenfassung: | |
**************************************************************** * USERS AFFECTED: * * ALL * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to DB2 version 10.1 fixpack 4 * **************************************************************** | |
| Local-Fix: | |
Workaround: 1) Manually rewrite the query to remove the subquery 2) db2set -im DB2_ANTIJOIN=NO | |
| verfügbare FixPacks: | |
DB2 Version 10.1 Fix Pack 4 for Linux, UNIX, and Windows | |
| Lösung | |
Upgrade to DB2 version 10.1 fixpack 4 | |
| Workaround | |
keiner bekannt / siehe Local-Fix | |
| Bug-Verfolgung | |
Vorgänger : APAR is sysrouted TO one or more of the following: IC98750 Nachfolger : | |
| Weitere Daten | |
Datum - Problem gemeldet : Datum - Problem geschlossen : Datum - der letzten Änderung: | 09.01.2014 02.06.2014 02.06.2014 |
| Problem behoben ab folgender Versionen (IBM BugInfos) | |
| Problem behoben lt. FixList in der Version | |
| 10.1.0.4 |
|