| From: | Sean Chittenden <sean(at)chittenden(dot)org> |
|---|---|
| To: | Clay Luther <claycle(at)cisco(dot)com> |
| Cc: | pgsql-general(at)postgresql(dot)org |
| Subject: | Re: left outer join terrible slow compared to inner join |
| Date: | 2003-08-28 18:31:39 |
| Message-ID: | 20030828183139.GL83759@perrin.nxad.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-general |
> Actually, I was about to post some problems we have with large left
> outer joins as well we've discovered in a porting project from
> NT/SQL Server -> Linux/Postgres.
>
> We have a particular query that is rather large, left outer joining
> across several tables. Under SQL Server, with identical data and
> schema, this particular query takes 2 seconds.
>
> Under PostgreSQL, this same query takes 90 seconds -- that's right,
> 90 seconds. 45x longer than SQL Server. This was quite a shock to
> us (we'd not seen such a performance deficit between the two dbs
> until this) and could, in fact, force us away from Postgres.
>
> I'd be happy to forward the explain to anyone who'd care to look at
> it...
Post an EXPLAIN ANALYZE of the query...
-sc
--
Sean Chittenden
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Clay Luther | 2003-08-28 18:47:28 | Re: left outer join terrible slow compared to inner join |
| Previous Message | Clay Luther | 2003-08-28 18:26:16 | Re: left outer join terrible slow compared to inner join |