| From: | Jeff Janes <jeff(dot)janes(at)gmail(dot)com> |
|---|---|
| To: | Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com> |
| Cc: | Willy-Bas Loos <willybas(at)gmail(dot)com>, "pgsql-performance(at)postgresql(dot)org" <pgsql-performance(at)postgresql(dot)org> |
| Subject: | Re: seqscan for 100 out of 3M rows, index present |
| Date: | 2013-06-26 20:31:29 |
| Message-ID: | CAMkU=1xzMULy-Ag=h_XK12MhnDtX=qus5YuiO1UV_TQ-c=dL9A@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-performance |
On Wed, Jun 26, 2013 at 12:07 PM, Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com>wrote:
> On Wed, Jun 26, 2013 at 9:45 AM, Willy-Bas Loos <willybas(at)gmail(dot)com>
> wrote:
> >
> > Aggregate (cost=60836.71..60836.72 rows=1 width=0) (actual
> > time=481.526..481.526 rows=1 loops=1)
> > -> Hash Join (cost=1296.42..60833.75 rows=1184 width=0) (actual
> > time=317.403..481.513 rows=17 loops=1)
> > Hash Cond: (d2.gid = g2.gid)
> > -> Seq Scan on d2 (cost=0.00..47872.54 rows=3107454 width=8)
> > (actual time=0.013..231.707 rows=3107454 loops=1)
>
> But this plan isn't retrieving just a few rows from d2, it's
> retreiving 3.1 Million rows.
>
But I think that that is the point. Why is it retrieving 3.1 million, when
it only needs 17?
Cheers,
Jeff
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Willy-Bas Loos | 2013-06-26 20:36:10 | Re: seqscan for 100 out of 3M rows, index present |
| Previous Message | Willy-Bas Loos | 2013-06-26 20:12:02 | Re: seqscan for 100 out of 3M rows, index present |