Re: "NOT IN" predicate hangs result

On Thu, Apr 11, 2002 at 09:42:59AM -0700, Stephan Szabo wrote:

> It probably would have finished eventually, but right now NOT IN has
> serious performance problems.  I believe that it's running the inner
> select once for every row in user_profile or something to that effect.
> And it's a known deficiency, it's even got its own FAQ question.

Just out of curiosity, is there a fundamental reason the optimiser
doesn't just rewrite NOT IN queries to use the NOT EXISTS form, or is
it simply that, since there's a well-known workaround, nobody's
bothered to improve this area?

A

--
----
Andrew Sullivan                               87 Mowat Avenue
Liberty RMS                           Toronto, Ontario Canada
<andrew@libertyrms.info>                              M6K 3E3
                                         +1 416 646 3304 x110