From: "Jason Kratz" <jkratz@rctanalytics.com>
Subject: Re: oracle very slow after computing stats
Date: 2000/06/06
Message-ID: <8hjmru$rd0$1@flood.xnet.com>#1/1
References: <8hj6vs$ivf$1@flood.xnet.com> <8hje3h$bn7$1@nnrp1.deja.com>
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Thanks Dave. I'll give that a shot tonight and see what happens.

Jason

<ddf_dba@my-deja.com> wrote in message news:8hje3h$bn7$1@nnrp1.deja.com...
> Jason,
>
> Once statistics are computed for a schema they must be kept current or
> performance will suffer.  At some point during the day statistics should
> be computed again, usually during a period of low activity.  I have run
> into this problem before and it was due to initially computing
> statistics on a schema and then never re-computing them.  You mention
> nightly data loads; this type of activity can quickly invalidate
> computed statistics and create slow response from the database on
> inserts, updates and queries.  Create a script to compute statistics on
> your tables and schedule it to run early in the morning.  This will
> improve performance considerably.
>
> David Fitzjarrell
> Oracle DBA
>
> In article <8hj6vs$ivf$1@flood.xnet.com>,
>   "Jason Kratz" <jkratz@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
> >
> >
>
>
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