Re: [PATCHES] Aggressive freezing in lazy-vacuum

From: "Florian G(dot) Pflug" <fgp(at)phlo(dot)org>
To: Heikki Linnakangas <heikki(at)enterprisedb(dot)com>
Cc: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, ITAGAKI Takahiro <itagaki(dot)takahiro(at)oss(dot)ntt(dot)co(dot)jp>, pgsql-hackers(at)postgresql(dot)org, pgsql-patches(at)postgresql(dot)org
Subject: Re: [PATCHES] Aggressive freezing in lazy-vacuum
Date: 2007-03-05 19:41:40
Message-ID: 45EC7274.20502@phlo.org
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Heikki Linnakangas wrote:
> Florian G. Pflug wrote:
>> There could be a GUC vacuum_freeze_limit, and the actual FreezeLimit
>> would be calculated as
>> GetOldestXmin() - vacuum_freeze_limit
>
> We already have that. It's called vacuum_freeze_min_age, and the default
> is 100 million transactions.
>
> IIRC we added it late in the 8.2 release cycle when we changed the clog
> truncation point to depend on freeze limit.

Ok, that explains why I didn't find it when I checked the source - I
checked the 8.1 sources by accident ;-)

Anyway, thanks for pointing that out ;-)

greetings, Florian Pflug

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