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From: cluster <skrald@amossen.dk>
To: Tom Lane <tgl@sss.pgh.pa.us>
Subject: Re: Query only slow on first run
Date: Thu, 29 Nov 2007 12:07:37 +0100
Message-ID: <474E9D79.6000407@amossen.dk> (raw)
In-Reply-To: <24967.1196288664@sss.pgh.pa.us>
References: <fihgt1$1mmh$1@news.hub.org>
	<20071127165543.GY11978@crankycanuck.ca>
	<23999.1196184368@sss.pgh.pa.us>
	<fihn7h$2jrn$1@news.hub.org>
	<056501c83128$55d58a90$8e00a8c0@tridecap.com>
	<fii71p$oc1$1@news.hub.org>
	<20071127233833.GA24031@uio.no>
	<15029.1196209554@sss.pgh.pa.us>
	<474CBF98.6070508@amossen.dk>
	<fikia6$26ql$1@news.hub.org>
	<20071128203442.GB30600@uio.no>
	<474DDA8F.3070801@amossen.dk>
	<24967.1196288664@sss.pgh.pa.us>

> You're essentially asking for a random sample of data that is not
> currently in memory.  You're not going to get that without some I/O.

No, that sounds reasonable enough. But do you agree with the statement 
that my query will just get slower and slower over time as the number of 
posts increases while the part having status = 1 is constant?
(Therefore, as the relevant fraction becomes smaller over time, the 
"Filter: status = 1" operation becomes slower.)



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