Re: improve 'where not exists' query..

On Tue, Oct 25, 2005 at 15:46:52 -0500,
  Noel Whelan <noel.whelan@gmail.com> wrote:
> I'm wondering if there's an ideal way to improve the efficiency of this
> query:
>
> SELECT i.id <http://i.id> FROM items i
> WHERE (NOT (EXISTS (SELECT c.id <http://c.id>
> FROM contacts c WHERE (c.id <http://c.id> = i.id <http://i.id>))));
>
> It takes a while to execute, clearly. Thank you,

On recent versions of postgres, NOT IN is potentially faster.

Have you looked at EXPLAIN ANALYZE output to see if anything looks amiss?