DB2 - Problem description
| Problem IC66296 | Status: Closed |
COMPRESSION STATISTIC PCTPAGESSAVED MAY BE INACCURATE. | |
| product: | |
DB2 FOR LUW / DB2FORLUW / 970 - DB2 | |
| Problem description: | |
PCTPAGESSAVED is set to 0 when RUNSTATS is executed on just the
indexes of the table via the FOR INDEXES clause, for example:
RUNSTATS ON TABLE s.t FOR INDEXES ALL
Under rare situations, incorrect intermediate calculations can
lead to an inaccurate PCTPAGESSAVED value, including 0 and
negative values. | |
| Problem Summary: | |
**************************************************************** * USERS AFFECTED: * * Users on V9.7 Fix Pack 1 and Below * **************************************************************** * PROBLEM DESCRIPTION: * * PCTPAGESSAVED is set to 0 when RUNSTATS is executed on just * * the * * indexes of the table via the FOR INDEXES clause, for * * example: * * RUNSTATS ON TABLE s.t FOR INDEXES ALL * * * * * * * * Under rare situations, incorrect intermediate calculations * * can * * lead to an inaccurate PCTPAGESSAVED value, including 0 and * * * * negative values. * **************************************************************** * RECOMMENDATION: * * Upgrade to V9.7 Fix Pack 2 or above * **************************************************************** | |
| Local Fix: | |
Determine compression benefit from other compression statistics
PCTROWSCOMPRESSED and AVGROWCOMPRESSIONRATIO.
If PCTPAGESSAVED is 0 after an index-only RUNSTATS operation,
collect statistics again, ensuring to collect statistics for the
table as well as its indexes, for example:
RUNSTATS ON TABLE s.t AND INDEXES ALL | |
| available fix packs: | |
DB2 Version 9.7 Fix Pack 2 for Linux, UNIX, and Windows | |
| Solution | |
First fixed in V9.7 Fix Pack 2 | |
| Workaround | |
not known / see Local fix | |
| Timestamps | |
Date - problem reported : Date - problem closed : Date - last modified : | 12.02.2010 12.08.2010 12.08.2010 |
| Problem solved at the following versions (IBM BugInfos) | |
9.7., 9.7.FP2 | |
| Problem solved according to the fixlist(s) of the following version(s) | |
| 9.7.0.2 |
|