DB2 - Problembeschreibung
Problem IC81623 | Status: Geschlossen |
EQUALITY JOIN PREDICATES PUSHED DOWN THRU OLAP FUNCTION FORMING A CORRELATION MAY CAUSE A PERFORMANCE DEGRADATION. | |
Produkt: | |
DB2 FOR LUW / DB2FORLUW / 970 - DB2 | |
Problembeschreibung: | |
Equality join predicates may be pushed down thru an OLAP function. The columns in the join predicates are required to be a superset of a unique index (or a primary key). The join predicates then will form a correlation, resulting in limiting the only join method eligible be the NLJOIN. This could cause a performance degradation. An indicator that a user has hit this problem is to look at the Optimized Statement of the db2exfmt output. (SELECT ..., <func>(<col> OVER (PARTITION NY <col>,...), ... FROM Q#3, ... WHERE Q#3.<col> = Q#2.<col> ) AS Q#1, <table> AS Q#2, ... If a correlated join predicate such as Q#3.<col> = Q#2.<col> is seen, this SQL statement may hit this problem. | |
Problem-Zusammenfassung: | |
**************************************************************** * USERS AFFECTED: * * DB2 UDB Version 9.7 * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to Version 9.7 FixPack 6. * **************************************************************** | |
Local-Fix: | |
verfügbare FixPacks: | |
DB2 Version 9.7 Fix Pack 6 for Linux, UNIX, and Windows | |
Lösung | |
Problem was first fixed in DB2 UDB Version 9.7 FixPack 6. | |
Workaround | |
keiner bekannt / siehe Local-Fix | |
Bug-Verfolgung | |
Vorgänger : APAR is sysrouted TO one or more of the following: IC84454 Nachfolger : | |
Weitere Daten | |
Datum - Problem gemeldet : Datum - Problem geschlossen : Datum - der letzten Änderung: | 23.02.2012 06.06.2012 06.06.2012 |
Problem behoben ab folgender Versionen (IBM BugInfos) | |
9.7.FP6 | |
Problem behoben lt. FixList in der Version | |
9.7.0.6 |