From: Mikko Partio <mpartio@gmail.com>
To: Alvaro Herrera <alvherre@commandprompt.com>
Cc: Pallav Kalva <pkalva@livedatagroup.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-performance@postgresql.org
Subject: Re: 8.2 Autovacuum BUG ?
Date: Fri, 31 Aug 2007 21:31:47 +0300
Message-ID: <2ca799770708311131r5ae5e3eera66a7cea1fc5917d@mail.gmail.com> (raw)
In-Reply-To: <20070831161158.GD8046@alvh.no-ip.org>
References: <46D83427.60001@livedatagroup.com>
<25038.1188574775@sss.pgh.pa.us>
<46D83C50.3040409@livedatagroup.com>
<20070831161158.GD8046@alvh.no-ip.org>
On 8/31/07, Alvaro Herrera <alvherre@commandprompt.com> wrote:
>
> Pallav Kalva wrote:
> > Tom Lane wrote:
>
> >> Probably represents freezing of old tuples, which is a WAL-logged
> >> operation as of 8.2. Is it likely that the data is 200M transactions
> >> old?
> >>
> > If nothing changed on these tables how can it freeze old tuples ?
> > Does it mean that once it reaches 200M transactions it will do the same
> > thing all over again ?
>
> No -- once tuples are frozen, they don't need freezing again (unless
> they are modified by UPDATE or DELETE).
>
>
Off-topic question: the documentation says that XID numbers are 32 bit.
Could the XID be 64 bit when running on a 64 bit platform? That would
effectively prevent wrap-around issues.
Regards
MP
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To: pgsql-performance@postgresql.org
Cc: mpartio@gmail.com, alvherre@commandprompt.com, pkalva@livedatagroup.com, tgl@sss.pgh.pa.us
Subject: Re: 8.2 Autovacuum BUG ?
In-Reply-To: <2ca799770708311131r5ae5e3eera66a7cea1fc5917d@mail.gmail.com>
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