DB2 - Problembeschreibung
Problem IC76337 | Status: Geschlossen |
THE OPTIMIZER MIGHT CHOOSE A SUB-OPTIMAL ACCESS PLAN FOR SQL USI NG RANGE PREDICATES WITH PLACE HOLDER VARIABLE. | |
Produkt: | |
DB2 FOR LUW / DB2FORLUW / 970 - DB2 | |
Problembeschreibung: | |
The optimizer might choose a sub-optimal nested loop join (NLJOIN) access plan for an SQL statement containing range predicates with place holder variables, where the inner input of the NLJOIN is an index-anding (IXAND) access of the base table; e.g. . select ... from tab1, tab2 where tab1.COLA=tab2.COLA and tab1.COLB >=? and tab1.COLC < ?; You can collect an EXPLAIN of the statement to verify the access plan chosen by the optimizer shows an NLJOIN with an IXAND over a single base table access on the inner (right) input where the index scans below the IXAND apply the join and range predicates. If the inner input includes a TEMP, and the statement includes an IN predicate with place holder variables in the values list such as "tab1.COLD IN (?,?,?,?)" then APAR IC73877 is a likely candidate. . You can use the REOPT ONCE/ALWAYS option to solve this issue. The sub-optimal access plan can be chosen as a result of errors in the cardinality estimate due to the unknown values to be used in the range predicates such as tab1.COLB >=? and tab1.COLC < ?. | |
Problem-Zusammenfassung: | |
**************************************************************** * USERS AFFECTED: * * ALL * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to product v9.7 Fix Pack 6. * **************************************************************** | |
Local-Fix: | |
You can use the REOPT ONCE/ALWAYS option to solve this issue. | |
verfügbare FixPacks: | |
DB2 Version 9.7 Fix Pack 6 for Linux, UNIX, and Windows | |
Lösung | |
First fixed in Version 9.7 Fix Pack 6. | |
Workaround | |
keiner bekannt / siehe Local-Fix | |
Bug-Verfolgung | |
Vorgänger : APAR is sysrouted TO one or more of the following: IC84493 Nachfolger : | |
Weitere Daten | |
Datum - Problem gemeldet : Datum - Problem geschlossen : Datum - der letzten Änderung: | 11.05.2011 19.06.2012 19.06.2012 |
Problem behoben ab folgender Versionen (IBM BugInfos) | |
9.7.FP6 | |
Problem behoben lt. FixList in der Version | |
9.7.0.6 |