Re: autovacuum next steps, take 2

From: "Matthew T(dot) O'Connor" <matthew(at)zeut(dot)net>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: "Jim C(dot) Nasby" <jim(at)nasby(dot)net>, Alvaro Herrera <alvherre(at)commandprompt(dot)com>, Hackers <pgsql-hackers(at)postgresql(dot)org>, Gregory Stark <stark(at)enterprisedb(dot)com>
Subject: Re: autovacuum next steps, take 2
Date: 2007-02-27 05:57:13
Message-ID: 45E3C839.3000105@zeut.net
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

Tom Lane wrote:
> "Jim C. Nasby" <jim(at)nasby(dot)net> writes:
>> The proposal to save enough state to be able to resume a vacuum at
>> pretty much any point in it's cycle might work; we'd have to benchmark
>> it. With the default maintenance_work_mem of 128M it would mean writing
>> out 64M of state every minute on average, which is likely to take
>> several seconds to fsync (though, maybe we wouldn't need to fsync it...)
>
> Which is exactly why we needn't bother benchmarking it. Even if it
> weren't complex and unsafe, it will be a net loss when you consider the
> fact that it adds I/O instead of removing it.

I'm not sure what you are saying here, are you now saying that partial
vacuum won't work for autovac? Or are you saying that saving state as
Jim is describing above won't work?

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Tom Lane 2007-02-27 06:20:30 Re: autovacuum next steps, take 2
Previous Message Tom Lane 2007-02-27 05:55:21 Re: Dead Space Map version 2