Re: oracle very slow after computing stats

You're probably better off doing a full compute, not an estimate of your statistics as well.

In article <8hjmru$rd0$1_at_flood.xnet.com>,   "Jason Kratz" <jkratz_at_rctanalytics.com> wrote:
> Thanks Dave. I'll give that a shot tonight and see what happens.
>
> Jason
>
> <ddf_dba_at_my-deja.com> wrote in message news:8hje3h$bn7
 $1_at_nnrp1.deja.com...
> > Jason,
> >
> > Once statistics are computed for a schema they must be kept current
 or
> > performance will suffer. At some point during the day statistics
 should
> > be computed again, usually during a period of low activity. I have
 run
> > into this problem before and it was due to initially computing
> > statistics on a schema and then never re-computing them. You
 mention
> > nightly data loads; this type of activity can quickly invalidate
> > computed statistics and create slow response from the database on
> > inserts, updates and queries. Create a script to compute
 statistics on
> > your tables and schedule it to run early in the morning. This will
> > improve performance considerably.
> >
> > David Fitzjarrell
> > Oracle DBA
> >
> > In article <8hj6vs$ivf$1_at_flood.xnet.com>,
> > "Jason Kratz" <jkratz_at_rctanalytics.com> wrote:
> > > We have an Oracle instance that is running considerably slower
 after
> > > computing stats. Heres the situation: I estimated stats at 25%
 on
 all
> > > tables in a schema (not SYS) and computed stats on all of the
 indexes
 in
> > > that schema (primary keys, etc are all seperated out from the data
 into
> > > seperate tablespaces). At first our nightly loads ran fine.
 After a
 day or
> > > so of the database up and running with stats the dataloads are
 running
> > > several times slower. We had this problem before but I had only
 computed
> > > stats on a few tables. When I dropped them before everything
 worked
 fine
> > > again. I was under the impression that most dbs should be running
 with
> > > computed stats. Shouldnt stats help increase db performance?
 Another
 note:
> > > this db is highly normalized resulting in rather large joins
 necessary
 when
> > > joins are done. Help!!!!
> > >
> > > Jason
> > >
> > >
> >
> >
> > Sent via Deja.com http://www.deja.com/
> > Before you buy.
>
>

Sent via Deja.com http://www.deja.com/
Before you buy. Received on Wed Jun 07 2000 - 00:00:00 CDT