From: Mark Kirkwood <mark.kirkwood@catalyst.net.nz>
To: Scott Marlowe <scott.marlowe@gmail.com>
Cc: Josh Berkus <josh@agliodbs.com>
Cc: Robert Haas <robertmhaas@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Bloat issue on 8.3; autovac ignores HOT new pages?
Date: Wed, 02 Feb 2011 12:37:30 +1300
Message-ID: <4D48993A.30207@catalyst.net.nz> (raw)
In-Reply-To: <AANLkTikw9e8-DwL8vVX=yOLOUiO5E4vjCkk4HhhXU-Lt@mail.gmail.com>
References: <4D3E34C8.9040209@agliodbs.com>
<AANLkTi=n6RCz_RSGhY4+AG6CbYWjLbKX6ohEvHoKNE+N@mail.gmail.com>
<4D3F163E.100@agliodbs.com>
<4D3F40BD.4040504@catalyst.net.nz>
<4D46FF15.7090606@agliodbs.com>
<AANLkTikw9e8-DwL8vVX=yOLOUiO5E4vjCkk4HhhXU-Lt@mail.gmail.com>
On 01/02/11 10:57, Scott Marlowe wrote:
> On Mon, Jan 31, 2011 at 11:27 AM, Josh Berkus<josh@agliodbs.com> wrote:
>> Robert, Mark,
>>
>> I have not been able to reproduce this issue in a clean test on 9.0. As
>> a result, I now think that it was related to the FSM being too small on
>> the user's 8.3 instance, and will consider it resolved.
> I used to try and size free space map to be a little bigger than it
> needed to be. I now size 4 or 5 times what it needs to be. shared
> memory is cheap. So is going to 8.4, but on legacy systems that you
> can't upgrade, 8.3 with a huge FSM works well enough (with suitably
> aggressive autovac).
>
Yeah, 8.3 with very aggressive autovac my experience too - I've had the
naptime cranked down to 10s or even 1s in some cases, to try to tame
bloat growth for web cache or session type tables that are heavily
volatile.
regards
Mark
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To: pgsql-performance@postgresql.org
Cc: mark.kirkwood@catalyst.net.nz, scott.marlowe@gmail.com, josh@agliodbs.com, robertmhaas@gmail.com
Subject: Re: Bloat issue on 8.3; autovac ignores HOT new pages?
In-Reply-To: <4D48993A.30207@catalyst.net.nz>
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