turning on cost-based is easy:  set the optimizer_mode parameter to choose 
in your init.ora, stop and start your database and then analyze all your 
tables.

HOWEVER (and this is a biggie) this will not automatically make all your 
queries run faster. You will need to examine each and every query to see if 
it needs to be rewritten to take advantage of CBO. In fact, sometimes there 
are queries that run faster in rule-based, and I have had to include hints 
in queries to force the optimizer to run rule.

>From: Venkat_Kalepalli <[EMAIL PROTECTED]>
>Reply-To: [EMAIL PROTECTED]
>To: Multiple recipients of list ORACLE-L <[EMAIL PROTECTED]>
>Subject: MTS&Cost based Optimzer
>Date: Tue, 24 Apr 2001 02:25:25 -0800
>
> > Hello folks!
> >
> > I am working in SUN solaris 5.6 with Oracle 8i.  I want to implement MTS
> > on the Oracle server.  Next we are running with Rule based optimizer and
> > we want to change to costbased optimizer.
> >
> > I want to know what are the advantages we get on this and what are the
> > steps to implement this?
> >
> > Any help is grateful...
> >
> > Rgd
> > Venkat
> > DBA.
> >
> >
> >

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