|
Problem IC70249
|
Status: Closed |
STATVIEW COLUMN STATISTICS NOT USED FOR CARDINALITY ESTIMATE FOR COMPLEX AND/OR PREDICATES |
| product: |
DB2 FOR LUW / DB2FORLUW / 950 - DB2 |
| Problem description: |
DB2 uses the individual column statistics to correct the
cardinality estimate for predicates applied to columns in views
enabled for optimization (statistical views, or statviews for
short). When the predicate involves combinations of AND and OR
predicates, the correction is not applied properly.
For example, the statview column statistics would be used to
estimate the filtering for predicates like:
"column1 >= 7 and column1 <= 9", or
"column1 = 7 or column1 = 9"
However, it would not be used to estimate the filtering for
predicates like:
"column1 >= 7 and column1 <= 9 or
column1 >= 15 and column1 <= 18"
This fix addresses the filtering estimate for the more complex
predicate with predicates combined with OR and AND. |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* ALL *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Problem Description above. *
****************************************************************
* RECOMMENDATION: *
* Upgrade to DB2 Version V9.5 Fix Pack 8. *
**************************************************************** |
| Local Fix: |
|
| available fix packs: |
DB2 Version 9.5 Fix Pack 8 for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 9 for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 10 for Linux, UNIX, and Windows
|
| Solution |
First fixed in DB2 Version V9.5 Fix Pack 8. |
| Workaround |
not known / see Local fix |
| BUG-Tracking |
forerunner : APAR is sysrouted TO one or more of the following: IC70255 IC70256
follow-up : |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 28.07.2010
05.07.2011
05.07.2011 |
| Problem solved at the following versions (IBM BugInfos) |
9.5.FP8
|
| Problem solved according to the fixlist(s) of the following version(s) |
| 9.5.0.8
|
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