In some cases, NOT IN is better than NOT EXISTS. In
other cases, the opposite is true.
Moral: It never pays to discount an option out of hand
- eg, NOT IN often works very very nicely for
uncorrelated subqueries
hth
connor
- "Post, Ethan" <Ethan.Post_at_ps.net> wrote: > Hold
the press. NOT IN better than NOT EXISTS? Is
> this theory or fact? If
> so is there any supporting evidence out there? This
> is the first I have
> heard of this.
>
> Thanks!
>
> -----Original Message-----
> Sent: Friday, November 15, 2002 11:35 AM
> To: Multiple recipients of list ORACLE-L
>
>
> Jerry,
>
> I suspect that the improvments are more likely due
> to your
> rewriting the WHERE clause rather than the use of
> NOT EXISTS.
>
> Especially if the database were 9i, where NOT IN
> actually
> seems get a better execution path than NOT EXISTS.
>
> That original WHERE clause is really a piece of
> work.
>
> Jared
>
>
>
> --
> Please see the official ORACLE-L FAQ:
> http://www.orafaq.com
> --
> Author: Post, Ethan
> INET: Ethan.Post_at_ps.net
>
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Received on Sat Nov 16 2002 - 12:08:24 CST
