DB2 - Problembeschreibung
Problem IC91223 | Status: Geschlossen |
INACCURATE DENSITY AND SEQUENTIAL_PAGES STATISTICS FOR PARTITIONED INDEXES MIGHT LEAD TO NON-OPTIMAL ACCESS PLANS | |
Produkt: | |
DB2 FOR LUW / DB2FORLUW / A10 - DB2 | |
Problembeschreibung: | |
DENSITY for partitioned indexes might be inaccurate when the partitioned table has a significant number of empty partitions. SEQUENTIAL_PAGES for partitioned indexes might be inaccurate and inconsistent with NLEAF when the partitioned table has a significant number of empty or near empty partitions. | |
Problem-Zusammenfassung: | |
**************************************************************** * USERS AFFECTED: * * ALL * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to DB2 Version 10.1 Fixpack 3. * **************************************************************** | |
Local-Fix: | |
1. Use optimization guidelines to direct the query optimizer to different access plans. 2. Alternately, provide the query optimizer with more accurate statistics via manually updating the relevant SYSSTAT.INDEXES rows. To determine what statistical values to use, one approach is to examine the per-partition index statistics in SYSCAT.INDEXESPARTITIONS and use a value representative from the majority of partitions with data. You can use the NUMRIDS statistics to assess if a partition is empty or near empty. When updating SEQUENTIAL_PAGES, a further consideration is its relationship to NLEAF. For example, if the majority of data holding partitions have SYSCAT.INDEXESPARTITIONS.SEQUENTIAL_PAGES near SYSCAT.INDEXESPARTITIONS.NLEAF, then update SYSTAT.INDEXES.SEQUENTIAL_PAGES so that it is near SYSTAT.INDEXES.NLEAF. | |
verfügbare FixPacks: | |
DB2 Version 10.1 Fix Pack 3 for Linux, UNIX, and Windows | |
Lösung | |
Fixed in Version 10.1 Fixpack 3. | |
Workaround | |
keiner bekannt / siehe Local-Fix | |
Weitere Daten | |
Datum - Problem gemeldet : Datum - Problem geschlossen : Datum - der letzten Änderung: | 02.04.2013 10.10.2013 10.10.2013 |
Problem behoben ab folgender Versionen (IBM BugInfos) | |
Problem behoben lt. FixList in der Version | |
10.1.0.3 | |
10.1.0.3 |