i analyzed some tables/indexes in my RULE based instance..
because i wanted to use the INDEX DESC hint in sql
> ----------
> From: John J. Kanagaraj[SMTP:john.j.kanagaraj_at_shell.com.bn]
> Sent: 26 April 2000 12:47
> To: oracledba_at_lazydba.com
> Cc: rajagopalvr_at_hotmail.com
> Subject: RE: Analyze in a Rule based Instance
>
> <<File: ATT350269.txt>>
> > Looks like all of u have concluded that CBO is not useful!
> <Snip>
> >
> > Regards
> > Rajagopal Venkataramany
>
> Hi Rajagopal,
>
> No offense meant, but I think this was not what the discussion was
> about! The subject at hand is not whether CBO is useful or not. The
> subject is :
>
> What happens if you analyze tables in a rule based instance (i.e.
> OPTIMIZER_MODE = RULE)?
>
> The general view seems to be that analyzing tables in a RULE based is
> bad. A test in one of my 'old' 7.3.4 RULE based instance (no Parallel
> query!) showed that the optimizer always chose RULE regardless of
> whether statistics were available or not. I would be interested in
> knowing more about the experience of others, i.e. how they determined
> that queries screwed up when stats were present, etc... Note that SYS
> schema should never have it's tables analyzed (was that the problem?)
>
> John Kanagaraj
> Brunei Shell Petroleum
> http://www.geocities.com/john_sharmila
>
> God so loved the world that He didn't send a committee! (See John 3:16
> for details)
> ** Opinions expressed here are solely mine and not necessarily those of
> my employer **
>
>
>
> > Subject: Re: Analyze in a Rule based Instance
> > Date: Mon, 24 Apr 2000 15:08:23 -0400
> >
> > I agree. We run a 7.3.4.4 Rule based instance and made the
> > mistake of
> > analyzing the tables. We will not be doing that again. All
> > users noticed a
> > big performance hit. As soon as we deleted the stats we were
Received on Wed Apr 26 2000 - 01:46:38 CDT
