|
Problem IC63200
|
Status: Closed |
INCORRECT XML CARDINALITY ESTIMATIONS SEEN WHEN EXECUTING CERTAIN TYPES OF XML QUERIES |
| product: |
DB2 FOR LUW / DB2FORLUW / 970 - DB2 |
| Problem description: |
This defects addresses a number of XML cardinality estimation
problems that are known to affect customer XML queries'
performance.
1) Failure to exploit BETWEEN predicate in XPath expression in
XSCAN causes incorrect estimation.
2) Incorrect XPath steps reconstruction when functional steps
are present rendered xmlstats non-exploitable.
3) Failure to recognize INLIST predicate as OR predicate
results in extreme underestimation.
4) Failure to recognized predicate of type <$I =
XML2SQL($j)> asa local predicate results in overestimation.
5) Incorrect comparison operator used when range
predicate is written as <const op col> results in
mis-estimation.
6) Incorrect comparison operator used
when BETWEEN predicate is written as <stop_search AND
start_search> results in mis-estimation.
7) Incorrect assumption when
'//" is used in a predicate resultsin mis-estimation. |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* All *
****************************************************************
* PROBLEM DESCRIPTION: *
* INCORRECT XML CARDINALITY ESTIMATIONS SEEN WHEN EXECUTING *
* CERTAIN TYPES OF XML QUERIES *
****************************************************************
* RECOMMENDATION: *
* Upgrade to V9.7 FP1 *
**************************************************************** |
| Local Fix: |
|
| available fix packs: |
DB2 Version 9.7 Fix Pack 1 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 2 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 3 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 3a for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 4 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 5 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 7 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 9a for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 6 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 8 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 9 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 10 for Linux, UNIX, and Windows
|
| Solution |
|
| Workaround |
not known / see Local fix |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 15.09.2009
04.02.2010
04.02.2010 |
| Problem solved at the following versions (IBM BugInfos) |
9.7.FP1
|
| Problem solved according to the fixlist(s) of the following version(s) |
| 9.7.0.1
|
 |
