Re: *** HELP ABOUT SINTAX *** --> order of predicates in where clause

From: Yong Huang <yong321_at_yahoo.com>
Date: 17 Sep 2004 11:56:49 -0700
Message-ID: <b3cb12d6.0409171056.ce28b30@posting.google.com>

"Mark C. Stock" <mcstockX_at_Xenquery .com> wrote in message news:<juGdnR0c3-acZNfcRVn-gg_at_comcast.com>...
>
> The order of predicates in the where clause is not as big an issue as it
> used to be as far as tuning -- of course, if you are using OR's then
> parenthesis placement is critical.
>
> You should download the Tuning manual and SQL manual at
> http://tahiti.oracle.com
>
> Any tuning gurus got anything to add about the order of where clause
> predicates and any effect on the optimizer?

Can you provide an example where order of predicates USED TO BE a big deal? Oracle9i Database Performance Tuning Guide and Reference, Chapter "Optimizer Hints", talks about ORDERED_PREDICATES hint and the order of evaluating the predicates without using this hint. There's no example in there.

Yong Huang Received on Fri Sep 17 2004 - 13:56:49 CDT