DB2 - Problembeschreibung
Problem IT00648 | Status: Geschlossen |
Query with joins and subquery predicates hangs when dbm config parm INTRA_PARALLEL is YES | |
Produkt: | |
DB2 FOR LUW / DB2FORLUW / A50 - DB2 | |
Problembeschreibung: | |
A query with joins and subquery predicates may hang with intraquery parallelism enabled. Whether the hang occurs depends on the access plan chosen by the optimizer and the table data the query is acting on. Vulnerable access plans can be identified by examining formatted EXPLAIN output. If an access plan has the following pattern it might be vulnerable: an NLJOIN or ZZJOIN operator with at least one NLJOIN, MSJOIN or ZZJOIN operator somewhere within its inner plan subtree, and then a subquery predicate subplan somewhere within the inner subtree of the nested join. | |
Problem-Zusammenfassung: | |
**************************************************************** * USERS AFFECTED: * * Users with intra-query parallelism enabled * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to DB2 Cancun Release 10.5.0.4. * **************************************************************** | |
Local-Fix: | |
Disable intraquery parallelism for the specific query by setting the CURRENT DEGREE special register to 1 prior to issuing the query, or, for static SQL, by setting the DEGREE bind option to 1. Alternatively, set the DFT_DEGREE database configuration parameter to 1 to disable intraquery parallelism by default for the database (and for static SQL, BIND again). | |
Lösung | |
Problem first fixed in DB2 Cancun Release 10.5.0.4. | |
Workaround | |
See local fix | |
Weitere Daten | |
Datum - Problem gemeldet : Datum - Problem geschlossen : Datum - der letzten Änderung: | 27.03.2014 08.09.2014 08.09.2014 |
Problem behoben ab folgender Versionen (IBM BugInfos) | |
Problem behoben lt. FixList in der Version | |
10.5.0.4 |