Re: [GENERAL] I feel the need for speed. What am I doing wrong?

From: "Dann Corbit" <DCorbit(at)connx(dot)com>
To: "johnnnnnn" <john(at)phaedrusdeinus(dot)org>, <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: [GENERAL] I feel the need for speed. What am I doing wrong?
Date: 2003-01-07 23:25:06
Message-ID: D90A5A6C612A39408103E6ECDD77B8294CD79F@voyager.corporate.connx.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

> -----Original Message-----
> From: johnnnnnn [mailto:john(at)phaedrusdeinus(dot)org]
> Sent: Tuesday, January 07, 2003 3:33 PM
> To: pgsql-hackers(at)postgresql(dot)org
> Subject: Re: [GENERAL] [HACKERS] I feel the need for speed.
> What am I doing wrong?
>
>
> On Tue, Jan 07, 2003 at 03:10:06PM -0800, Dann Corbit wrote:
> > NOTICE: QUERY PLAN:
> >
> > SetOp Except (cost=202028537.97..202120623.90 rows=1227812
> width=24)
> > -> Sort (cost=202028537.97..202028537.97 rows=12278124 width=24)
> > -> Append (cost=100000000.00..200225099.24 rows=12278124
> > width=24)
> > -> Subquery Scan *SELECT* 1
> > (cost=100000000.00..100112549.62 rows=6139062 width=24)
> > -> Seq Scan on CNX_DS_53_SIS_STU_OPT_FEE_TB a
> > (cost=100000000.00..100112549.62 rows=6139062 width=24)
> > -> Subquery Scan *SELECT* 2
> > (cost=100000000.00..100112549.62 rows=6139062 width=24)
> > -> Seq Scan on CNX_DS2_53_SIS_STU_OPT_FEE_TB b
> > (cost=100000000.00..100112549.62 rows=6139062 width=24)
> >
> > EXPLAIN
>
> Those big round numbers suggest that you haven't run vacuum
> analyze on all of your tables. Since PostgreSQL uses a
> cost-based optimizer, you do actually have to give it some
> idea of what things will cost before it can give you an
> appropriate plan.
>
> Reference for your version:
> http://www14.us.postgresql.org/users-lounge/docs/7.1/reference
/sql-vacuum.html

No analyze for 7.1.3.
Just ran vacuum a few minutes before the query. No boost at all. Even
with SET enable_seqscan = 0 it still does a table scan.

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Larry Rosenman 2003-01-07 23:28:46 Re: [GENERAL] I feel the need for speed. What am I doing
Previous Message scott.marlowe 2003-01-07 23:16:09 Re: [PERFORM] PostgreSQL and memory usage