Re: seq scan issue...

From: "Jeffrey Baker" <jwbaker(at)gmail(dot)com>
To: "kevin kempter" <kevin(at)kevinkempterllc(dot)com>, pgsql-performance(at)postgresql(dot)org
Subject: Re: seq scan issue...
Date: 2008-04-17 18:30:15
Message-ID: fd145f7d0804171130g6549ace3u14876385420f8c11@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-performance

On Thu, Apr 17, 2008 at 11:24 AM, kevin kempter
<kevin(at)kevinkempterllc(dot)com> wrote:
> Hi List;
>
> I have a large tble (playback_device) with 6million rows in it. The
> aff_id_tmp1 table has 600,000 rows.
> - why am I still getting a seq scan ?
>

You're selecting almost all the rows in the product of aff_id_tmp1 *
playback_fragment. A sequential scan will be far faster than an index
scan. You can prove this to yourself using 'set enable_seqscan to
false' and running the query again. It should be much slower.

In response to

Browse pgsql-performance by date

  From Date Subject
Next Message Rodrigo Gonzalez 2008-04-17 18:31:10 Re: seq scan issue...
Previous Message kevin kempter 2008-04-17 18:24:26 seq scan issue...