|
Problem IC98878
|
Status: Geschlossen |
DB2 OPTIMIZER CAN CHOOSE A SUB-OPTIMAL PLAN FOR A TABLE THAT HAS A HIGH ROWS-PER-PAGE NUMBER |
| Produkt: |
DB2 FOR LUW / DB2FORLUW / A10 - DB2 |
| Problembeschreibung: |
When a table has a high rows-per-page number, DB2 optimizer can
be too conservative with the estimate and as a result,
prefetching may not occur for a IXSCAN-FETCH operation on such a
table, even when the index has a high cluster ratio. This can
result in a sub-optimal query plan. |
| Problem-Zusammenfassung: |
****************************************************************
* USERS AFFECTED: *
* All users *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Error Description *
****************************************************************
* RECOMMENDATION: *
* Upgrade to version 10.1 Fix Pack 1 or later. *
**************************************************************** |
| Local-Fix: |
|
| Lösung |
Problem was first fixed in Version 10.1 Fix Pack 1.
The fix is not enabled by default. To enable it, set the
following registry:
DB2_EXTENDED_OPTIMIZATION=PG_CR |
| Workaround |
keiner bekannt / siehe Local-Fix |
| Weitere Daten |
Datum - Problem gemeldet :
Datum - Problem geschlossen :
Datum - der letzten Änderung:
| 21.01.2014
21.01.2014
28.01.2014 |
| Problem behoben ab folgender Versionen (IBM BugInfos) |
9.7.FP6
|
| Problem behoben lt. FixList in der Version |
