DB2 - Problembeschreibung
Problem IC83952 | Status: Geschlossen |
Queries with large IN predicates on the same column as an equality join may perform poorly | |
Produkt: | |
DB2 FOR LUW / DB2FORLUW / 970 - DB2 | |
Problembeschreibung: | |
A query that contains a large IN predicate applied to the same column as an equality join may show a RIDSCAN consuming many IXSCAN inputs instead of using a nested loop join to probe the index with the key values. For example the following query could suffer from this issue when both T1.c1 and T2.c1 have indexes defined. SELECT * FROM T1, T2 WHERE T1.c1 = T2.c1 AND T1.c1 in (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?) Upon examination of the access plan you may see a NLJOIN between T1 and a GENROW operator followed by a subsequent join to T2 that is accessed using RIDSCAN with many IXSCAN input plans. | |
Problem-Zusammenfassung: | |
**************************************************************** * USERS AFFECTED: * * ALL * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to DB2 Version 9.7 Fix pack 7. * **************************************************************** | |
Local-Fix: | |
Create and apply an optimization profile that forces the IN to join plan using the following guideline <OPTGUIDELINES><INLIST2JOIN/></OPTGUIDELINES> | |
verfügbare FixPacks: | |
DB2 Version 9.7 Fix Pack 7 for Linux, UNIX, and Windows | |
Lösung | |
First fixed in DB2 Version 9.7 Fix Pack 7. | |
Workaround | |
keiner bekannt / siehe Local-Fix | |
Bug-Verfolgung | |
Vorgänger : APAR is sysrouted TO one or more of the following: IC88650 IC88680 Nachfolger : | |
Weitere Daten | |
Datum - Problem gemeldet : Datum - Problem geschlossen : Datum - der letzten Änderung: | 05.06.2012 14.12.2012 14.12.2012 |
Problem behoben ab folgender Versionen (IBM BugInfos) | |
9.7.FP7 | |
Problem behoben lt. FixList in der Version | |
9.7.0.7 |