DB2 - Problembeschreibung
| Problem IC84565 | Status: Geschlossen |
ESTIMATED CARDINALITY OF UNNEST FUNCTION FOR ARRAY DATATYPE IS NOT USED DURING QUERY PLANNING | |
| Produkt: | |
DB2 FOR LUW / DB2FORLUW / A10 - DB2 | |
| Problembeschreibung: | |
The DB2 optimizer uses the maximum cardinality of an array during plan generation. In many cases the maximum cardinality is not a good indicator of the real array size, especially when arrays are used in stored procedures or packages. As a result, queries that use the UNNEST function with an array as input may have poor plans due to the high maximum array cardinality. | |
| Problem-Zusammenfassung: | |
**************************************************************** * USERS AFFECTED: * * All users in DB2 V10 GA * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to DB2 v10 FP1 * **************************************************************** | |
| Local-Fix: | |
As a workaround, the user may specify an estimated cardinality for the array by updating the statistics of the array cast function in SYSSTAT.ROUTINES table: db2 "update sysstat.routines set cardinality=<cardinality_of_array> where routineschema='<schema_name_of_array>' and routinename='<array_name>'" Dynamic statements will use the new cardinality at the next compile. Static packages will need to be rebound to use the new cardinality. | |
| verfügbare FixPacks: | |
DB2 Version 10.1 Fix Pack 1 for Linux, UNIX, and Windows | |
| Lösung | |
First Fixed in DB2 v10 FP1 | |
| Workaround | |
keiner bekannt / siehe Local-Fix | |
| Weitere Daten | |
Datum - Problem gemeldet : Datum - Problem geschlossen : Datum - der letzten Änderung: | 14.06.2012 01.11.2012 01.11.2012 |
| Problem behoben ab folgender Versionen (IBM BugInfos) | |
| Problem behoben lt. FixList in der Version | |
| 10.1.0.1 |
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| 10.5.0.1 |
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