Message-ID: <4929D923.7050001@zeut.net>
Date: Sun, 23 Nov 2008 17:28:51 -0500
From: "Matthew T. O'Connor" <matthew@zeut.net>
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To: Tom Lane <tgl@sss.pgh.pa.us>
CC: Jeff Davis <pgsql@j-davis.com>,
	Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>,
	PostgreSQL-development <pgsql-hackers@postgresql.org>
Subject: Re: Visibility map, partial vacuums
References: <4905AE17.7090305@enterprisedb.com>
	<491D376B.9000608@enterprisedb.com>
	<491D7F52.6070908@enterprisedb.com>
	<4925664C.3090605@enterprisedb.com>
	<26361.1227467112@sss.pgh.pa.us>
	<1227471538.7370.14.camel@jdavis-laptop>
	<27709.1227475122@sss.pgh.pa.us>
In-Reply-To: <27709.1227475122@sss.pgh.pa.us>
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Tom Lane wrote:
> However, my comment above was too optimistic, because in an insert-only
> scenario autovac would in fact not trigger VACUUM at all, only ANALYZE.
>
> So it seems like we do indeed want to rejigger autovac's rules a bit
> to account for the possibility of wanting to apply vacuum to get
> visibility bits set.

I'm sure I'm missing something, but I thought the point of this was to 
lessen the impact of VACUUM and now you are suggesting that we have to 
add vacuums to tables that have never needed one before.