From: Peter Eisentraut <peter_e@gmx.net>
To: Steinar H. Gunderson <sgunderson@bigfoot.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Index scan startup time
Date: Thu, 30 Mar 2006 14:59:02 +0200
Message-ID: <200603301459.03011.peter_e@gmx.net> (raw)
In-Reply-To: <20060330123134.GA13408@uio.no>
References: <200603301359.11038.peter_e@gmx.net>
<200603301423.54510.peter_e@gmx.net>
<20060330123134.GA13408@uio.no>
Am Donnerstag, 30. März 2006 14:31 schrieb Steinar H. Gunderson:
> Well, it's logical enough; it scans along activity_id until it finds one
> with state=10000 or state=10001. You obviously have a _lot_ of records with
> low activity_id and state none of these two, so Postgres needs to scan all
> those records before it founds 100 it can output. This is the “startup
> cost” you're seeing.
The startup cost is the cost until the plan is set up to start outputting
rows. It is not the time until the first row is found.
--
Peter Eisentraut
http://developer.postgresql.org/~petere/
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To: pgsql-performance@postgresql.org
Cc: peter_e@gmx.net, sgunderson@bigfoot.com
Subject: Re: Index scan startup time
In-Reply-To: <200603301459.03011.peter_e@gmx.net>
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