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Home -> Community -> Mailing Lists -> Oracle-L -> RE: MTS&Cost based Optimzer
How would you decide that out of total big and small tables (say 1500) these are the tables need to be analysed and these are not, as in our case Transaction types are both OLTP and DSS ??
-----Original Message-----
Carmichael
Sent: Tuesday, April 24, 2001 6:46 PM
To: Multiple recipients of list ORACLE-L
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 <Venkat_Kalepalli_at_satyam.com>
>Reply-To: ORACLE-L_at_fatcity.com
>To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
>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.
> >
> >
> >
-- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Rachel Carmichael INET: carmichr_at_hotmail.com Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Deepender Kr Gupta INET: deepender.gupta_at_wipro.com Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).Received on Tue Apr 24 2001 - 09:16:51 CDT
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