From: Josh Berkus <josh@agliodbs.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: PostgreSQL-development <pgsql-hackers@postgresql.org>
Subject: Re: Return of the Solaris vacuum polling problem -- anyone remember this?
Date: Wed, 18 Aug 2010 12:02:34 -0700
Message-ID: <4C6C2E4A.1010506@agliodbs.com> (raw)
In-Reply-To: <8599.1282158010@sss.pgh.pa.us>
References: <4C69827A.409@agliodbs.com>
<19969.1281986537@sss.pgh.pa.us>
<4C6C2B2B.9060501@agliodbs.com>
<8599.1282158010@sss.pgh.pa.us>
> On further reflection, though: since we put in the BufferAccessStrategy
> code, which was in 8.3, the background writer isn't *supposed* to be
> very much involved in writing pages that are dirtied by VACUUM. VACUUM
> runs in a small ring of buffers and is supposed to have to clean its own
> dirt most of the time. So it's wrong to blame this on the bgwriter not
> holding up its end. Rather, what you need to be thinking about is how
> come vacuum seems to be making lots of pages dirty on only one of these
> machines.
This is an anti-wraparound vacuum, so it could have something to do with
the hint bits. Maybe it's setting the freeze bit on every page, and
writing them one page at a time? Still don't understand the call to
pollsys, even so, though.
--
-- Josh Berkus
PostgreSQL Experts Inc.
http://www.pgexperts.com
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To: pgsql-hackers@postgresql.org
Cc: josh@agliodbs.com, tgl@sss.pgh.pa.us
Subject: Re: Return of the Solaris vacuum polling problem -- anyone remember this?
In-Reply-To: <4C6C2E4A.1010506@agliodbs.com>
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