| From: | Christopher Kings-Lynne <chriskl(at)familyhealth(dot)com(dot)au> |
|---|---|
| To: | Joe Conway <mail(at)joeconway(dot)com> |
| Cc: | Becky Neville <rebecca(dot)neville(at)yale(dot)edu>, <andrew(at)libertyrms(dot)info>, <pgsql-performance(at)postgresql(dot)org> |
| Subject: | Re: NOT IN doesn't use index? (fwd) |
| Date: | 2003-05-04 04:05:42 |
| Message-ID: | 20030504120511.M43020-100000@houston.familyhealth.com.au |
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| Thread: | |
| Lists: | pgsql-performance |
AFAIK, it's only the IN (large subquery) form that is slow...
Chris
On Sat, 3 May 2003, Joe Conway wrote:
> Becky Neville wrote:
> > Here is the EXPLAIN output from the two queries. The first is the one
> > that uses WHERE field NOT IN ( 'a','b' etc ). The second is the (much
>
> Unless you are working with Postgres 7.4devel (i.e. cvs HEAD), the IN
> construct is notoriously slow in Postgres. In cvs it is vastly improved.
>
> Also, as I mentioned in the other reply, send in "EXPLAIN ANALYZE"
> results instead of "EXPLAIN" (and make sure you run "VACUUM ANALYZE" first).
>
> Joe
>
>
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