Re: Improve this querry!?

From: Jan van Mourik <jmourik_at_yahoo.com>
Date: 10 Nov 2003 13:39:32 -0800
Message-ID: <ffe966de.0311101339.41fb6c46@posting.google.com>

Lothar Armbruester <lothar.armbruester_at_t-online.de> wrote in message
> Hello Mark,
> maybe you gain some performance using a hash antijoin whith your NOT IN
> clause. Have a look at the docs. Since NOT IN is one of the slowest
> operations one can do with a database, this may boost your performance.
> The HASH_AJ hint has some prerequisites to work properly though.

Lothar,

on my test set with 1m rows in both tables, the CBO chose the hash join for each query shown above, including Mark's original query with the NOT IN. Have to mention this is on 9.2.0.3 though.

jan Received on Mon Nov 10 2003 - 15:39:32 CST