Re: Analyze problem?

Thank you very much! I will try it.

"Robert Fazio" <rfazio_at_home.com.nospam> wrote in message news:3pN17.4224$Y6.1343308_at_news1.rdc2.pa.home.com...
> The statistics are based upon what it sees at the time they are run. Any
 of
> the following could be your cause.
>
> 1) The stats get out of date due to the deletes.
> 2) The data layout is much better suited for index access, but basic stats
> don't show it.
> For example: table with a is_true column (boolean value) true or
 false.
> 90% of the rows are True, but you always query on False. Index access
 would
> be faster, but Oracle will choose Full Table Scan. 2 values yields 50%
> rows, hence a full table scan. Rule will naturally use index so it runs
> better.
>
> Consider adding histograms.
>
> sql> analyze table t_name compute statistics for all indexed columns;
>
> See if that helps.
>
> "Little Prince" <milan1810_at_geocities.com> wrote in message
> news:9i3lam$24818_at_ctmsun0.macau.ctm.net...
> > I use ANALYZE...COMPUTER STATISTICS command to analyze two tables which
 are
> > used in a DELETE statement in a batch job. The performance of the job
> > obviously drops a lot. The execution time is server times longer than
> > before. But, after I use ANALYZE...DELETE STATISTICS to remove the
> > statistics, the execution time of the job is much shorter. Anyone can
 give
> > me some advices? As I know statistics can improve performance, why is my
> > case?
> >
> > Andrew
> >
> >
>
>
Received on Mon Jul 09 2001 - 11:22:45 CDT