Skip site navigation (1) Skip section navigation (2)

Re: Strange cost computation?

From: Stephan Szabo <sszabo(at)megazone23(dot)bigpanda(dot)com>
To: Ives Landrieu <ives(dot)landrieu(at)ua(dot)ac(dot)be>
Cc: <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Strange cost computation?
Date: 2002-10-30 16:12:12
Message-ID: 20021030081123.H31599-100000@megazone23.bigpanda.com (view raw or flat)
Thread:
Lists: pgsql-hackers
On Wed, 30 Oct 2002, Stephan Szabo wrote:

> On 29 Oct 2002, Ives Landrieu wrote:
>
> > Hi,
> >
> > Can anybody explain the following results when using EXPLAIN,
> > one time with enable_seqscan=on and one time with enable_seqscan=off.
> > What I don't understand is that the nodes created are the same
> > (index scan, seq scan), but the costs differ.
>
> Enable seq scan actually just sets a large cost disbenefit to seq scans.

Boy, that sentence sure didn't make sense.  enable_seqscan=off actually
gives a large cost disbenefit to seqscans.


In response to

pgsql-hackers by date

Next:From: Paul RamseyDate: 2002-10-30 16:24:56
Subject: Re: OO future
Previous:From: Stephan SzaboDate: 2002-10-30 15:59:56
Subject: Re: Strange cost computation?

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group