DB2 - Problembeschreibung
Problem IC63200 | Status: Geschlossen |
INCORRECT XML CARDINALITY ESTIMATIONS SEEN WHEN EXECUTING CERTAIN TYPES OF XML QUERIES | |
Produkt: | |
DB2 FOR LUW / DB2FORLUW / 970 - DB2 | |
Problembeschreibung: | |
This defects addresses a number of XML cardinality estimation problems that are known to affect customer XML queries' performance. 1) Failure to exploit BETWEEN predicate in XPath expression in XSCAN causes incorrect estimation. 2) Incorrect XPath steps reconstruction when functional steps are present rendered xmlstats non-exploitable. 3) Failure to recognize INLIST predicate as OR predicate results in extreme underestimation. 4) Failure to recognized predicate of type <$I = XML2SQL($j)> asa local predicate results in overestimation. 5) Incorrect comparison operator used when range predicate is written as <const op col> results in mis-estimation. 6) Incorrect comparison operator used when BETWEEN predicate is written as <stop_search AND start_search> results in mis-estimation. 7) Incorrect assumption when '//" is used in a predicate resultsin mis-estimation. | |
Problem-Zusammenfassung: | |
**************************************************************** * USERS AFFECTED: * * All * **************************************************************** * PROBLEM DESCRIPTION: * * INCORRECT XML CARDINALITY ESTIMATIONS SEEN WHEN EXECUTING * * CERTAIN TYPES OF XML QUERIES * **************************************************************** * RECOMMENDATION: * * Upgrade to V9.7 FP1 * **************************************************************** | |
Local-Fix: | |
verfügbare FixPacks: | |
DB2 Version 9.7 Fix Pack 1 for Linux, UNIX, and Windows | |
Lösung | |
Workaround | |
keiner bekannt / siehe Local-Fix | |
Weitere Daten | |
Datum - Problem gemeldet : Datum - Problem geschlossen : Datum - der letzten Änderung: | 15.09.2009 04.02.2010 04.02.2010 |
Problem behoben ab folgender Versionen (IBM BugInfos) | |
9.7.FP1 | |
Problem behoben lt. FixList in der Version | |
9.7.0.1 |