DB2 - Problembeschreibung
Problem IC78123 | Status: Geschlossen |
AN APPLICATION MAY APPEAR TO BE STUCK IN "UOW EXECUTING" STATE WHEN EXECUTING A PLAN CONTAINING AN INDEX AND OPERATION. | |
Produkt: | |
DB2 CONNECT / DB2CONNCT / 950 - DB2 | |
Problembeschreibung: | |
An application may appear to be stuck in "UOW Executing" state when executing query with an execution plan that includes an index AND operation. It will be characterised by high CPU usage for one or more EDUs processing the query on behalf of the application. Index ANDing represents the logical AND of results from multiple index scans on the same source object to satisfy the filtering criteria or to merge the results of semi-joins used in star joins. Examination of the stack for an EDU involved in this processing will be similar to the following: ========================================== sqlri_BFBandP sqliScanLeaf2NoLocking sqlifnxt sqlirdk sqldIndexFetch sqldIndexFetch sqldRowFetch ...... ========================================== The application isn't truly hung but may take an unrealistic amount of time to complete and may be forced using the FORCE APPLICATION command. | |
Problem-Zusammenfassung: | |
**************************************************************** * USERS AFFECTED: * * All users of version 9.5 on Linux, Unix and Windows * * platforms. * **************************************************************** * PROBLEM DESCRIPTION: * * An application may appear to be stuck in "UOW Executing" * * state when executing query with an execution plan that * * includes an index AND operation. It will be characterised by * * high CPU usage for one or more EDUs processing the query on * * behalf of the application. * * * * Index ANDing represents the logical AND of results from * * multiple index scans on the same source object to satisfy * * the filtering criteria or to merge the results of semi-joins * * used in star joins. * * * * Examination of the stack for an EDU involved in this * * processing will be similar to the following: * * ========================================== * * sqlri_BFBandP * * sqliScanLeaf2NoLocking * * sqlifnxt * * sqlirdk * * sqldIndexFetch * * sqldIndexFetch * * sqldRowFetch * * ...... * * ========================================== * * * * The application isn't truly hung but may take an unrealistic * * amount of time to complete and may be forced using the FORCE * * APPLICATION command. * **************************************************************** * RECOMMENDATION: * * Upgrade to DB2 LUW Version 9.5 FixPak 9 or higher levels. * **************************************************************** | |
Local-Fix: | |
Use the query explain tools to check the access plan for the executing SQL and create necessary indices to avoid the index AND operations. | |
verfügbare FixPacks: | |
DB2 Version 9.5 Fix Pack 9 for Linux, UNIX, and Windows | |
Lösung | |
First fixed in DB2 LUW Version 9.5 FixPak 9. | |
Workaround | |
Use the query explain tools to check the access plan for the executing SQL and create necessary indices to avoid the index AND operations. | |
Bug-Verfolgung | |
Vorgänger : APAR is sysrouted TO one or more of the following: IC78143 Nachfolger : | |
Weitere Daten | |
Datum - Problem gemeldet : Datum - Problem geschlossen : Datum - der letzten Änderung: | 14.08.2011 12.03.2012 12.03.2012 |
Problem behoben ab folgender Versionen (IBM BugInfos) | |
9.0., 9.5. | |
Problem behoben lt. FixList in der Version | |
9.5.0.9 |