Re: DBMS_STATS

From: Mogens Nørgaard <mln_at_miracleas.dk>
Date: Wed, 16 Jun 2004 09:55:54 +0200
Message-ID: <40CFFD0A.4090801@miracleas.dk>

Can't remember if you got any responses on this - if you did, then I apologize for any repetitions...

There's no correct answer to this question - if there was, it would be part of the DBMS_STATS thing now, I bet :-)

I would suggest the following (subject to debate, please):

Collect stats (sample 1 percent) on all your objects OR
Import stats from your test system (or another similar system)
If there are performance problems somewhere, fix them with either SQL statement tuning or Breitlings methods, or whatever
If a table grows a LOT in size, re-analyze.
Otherwise, don't touch anything until somebody complains. What Peter Gram from Miracle has called Compulsive Analyze DisOrder (CADO) is perhaps fun, but mostly not needed.

Why the 1 percent sample? Because that's what the Oracle benchmark guys do, so I figured it might be good enough. From a purely statistical point of view it ought to be, too.

Special problems exist, but this is my first suggestion.

Mogens

April Wells wrote:

> Carel-Jan
>
> It is a really good paper, one that I will now read over pretty
> extensively... but I'm not sure it answers her questions on DBMS_STATS and
> how best to collect statistics effectively.
>
> I do want to see any good doc on it to. We are using DBMS_STATS in
> production, in all of our instances, but I'm not comfortable that we are
> implementing as well as we could, either.
>
> ajw
>
> April Wells
> Oracle DBA/Oracle Apps DBA
> Corporate Systems
> Amarillo Texas
> @>-->-->--
> "Few people really enjoy the simple pleasure of flying a kite"
> Adam Wells age 11
> "Imagination is the highest kite one can fly."
> Lauren Bacall
>
>

Please see the official ORACLE-L FAQ: http://www.orafaq.com

To unsubscribe send email to: oracle-l-request_at_freelists.org put 'unsubscribe' in the subject line.

--
Archives are at http://www.freelists.org/archives/oracle-l/
FAQ is at http://www.freelists.org/help/fom-serve/cache/1.html
-----------------------------------------------------------------

Received on Wed Jun 16 2004 - 14:18:39 CDT