DB2 - Problembeschreibung
Problem IC80673 | Status: Geschlossen |
WRONG PREFETCH SIZE CALCULATION FOR AUTOMATIC STORAGE | |
Produkt: | |
DB2 FOR LUW / DB2FORLUW / 970 - DB2 | |
Problembeschreibung: | |
In case you use PREFETCHSIZE AUTOMATIC with AUTOMATIC STORAGE, there could be a miscalculation of the PREFETCH SIZE used. The intention of this APAR is to fix the the prefetch size calculation. However, there is a more subtle and complex issue here. In our design, each table has a packed descriptor and the packed descriptor contains a bunch of information including the tablespace's prefetch size. When the tablespace's prefetch size changes, we need to update the packed descriptors of ALL the tables and indexes within this tablespace. This is a complex issue because the packed descriptors are stored in the system catalog. This is how it's done in the ALTER TABLESPACE PREFETCHSIZE codepath. However, the automatic storage codepath does not have the infrastructure to do all these. Fixing this is too risky to be done in an APAR fix. There is a simple workaround available: 1. ALTER TABLESPACE PREFETCHSIZE <some number> 2. ALTER TABLESPACE PREFETCHSIZE AUTOMATIC " | |
Problem-Zusammenfassung: | |
**************************************************************** * USERS AFFECTED: * * All * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to DB2 Version 9.7 Fix Pack 6. * **************************************************************** | |
Local-Fix: | |
1. ALTER TABLESPACE PREFETCHSIZE <some number> 2. ALTER TABLESPACE PREFETCHSIZE AUTOMATIC " NOTE: Workaround is good till new stripe set is not created. Once containers get filled and new stripe set needs to be created, then prefetch size will be miscalculated again. | |
verfügbare FixPacks: | |
DB2 Version 9.7 Fix Pack 6 for Linux, UNIX, and Windows | |
Lösung | |
First fixed in DB2 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: IC84583 Nachfolger : | |
Weitere Daten | |
Datum - Problem gemeldet : Datum - Problem geschlossen : Datum - der letzten Änderung: | 05.01.2012 06.06.2012 22.06.2012 |
Problem behoben ab folgender Versionen (IBM BugInfos) | |
9.7.FP6 | |
Problem behoben lt. FixList in der Version | |
9.7.0.6 |