DB2 - Problembeschreibung
Problem IC72117 | Status: Geschlossen |
TRUNCATED SORT OF STAR JOIN DIMENSION TABLES CAUSES INCORRECT RESULTS | |
Produkt: | |
DB2 FOR LUW / DB2FORLUW / 970 - DB2 | |
Problembeschreibung: | |
When a query uses Fetch First N Rows Only, and has a series of lossless Referential Integrety (RI) Joins, the optimizer may choose to use a truncated operator, such as a Truncated SORT or a Truncated Table Queue. The optimizer may then incorrectly choose to truncate the join of a series of dimension tables, leading to incorrect results. This can most commonly be identified by looking for the following argument on either a SORT: TRUNCSRT: (Truncated sort (for Fetch First n Rows Only)) TRUE or a TABLE QUEUE (TQ) operator: TRUNCTQ : (Truncated Table Queue (for Fetch First n Rows Only)) <value> where <value> could be any one of "INPUT", "OUTPUT" or "INPUT AND OUTPUT" If either of these operators occur in a plan that contains only the dimension tables, then the plan may return incorrect results, if the join between the dimension tables produces more tuples then the truncated operator will allow to be produced. | |
Problem-Zusammenfassung: | |
APAR fix was provided in Fixpack 4. | |
Local-Fix: | |
Remove Fetch First N Rows from the query | |
verfügbare FixPacks: | |
DB2 Version 9.7 Fix Pack 4 for Linux, UNIX, and Windows | |
Lösung | |
The fix ensures correct result set is returned for the case in question. | |
Workaround | |
keiner bekannt / siehe Local-Fix | |
Weitere Daten | |
Datum - Problem gemeldet : Datum - Problem geschlossen : Datum - der letzten Änderung: | 22.10.2010 09.05.2011 09.05.2011 |
Problem behoben ab folgender Versionen (IBM BugInfos) | |
Problem behoben lt. FixList in der Version | |
9.7.0.4 |