From: Scott Marlowe <scott.marlowe@gmail.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Josh Berkus <josh@agliodbs.com>
Cc: Rick <richard.branton@ca.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: autovacuum strategy / parameters
Date: Sat, 1 May 2010 13:19:47 -0600
Message-ID: <i2gdcc563d11005011219wd97f29a3l4eec3eefbed07a77@mail.gmail.com> (raw)
In-Reply-To: <m2mdcc563d11005011217nb578578bz68c99276ceaf0e45@mail.gmail.com>
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<y2g603c8f071004221155h3874a3c0ybbe2c790e3c1bf80@mail.gmail.com>
<65d9d15d-41d2-4bfa-8cc3-6148b4fb9022@z3g2000yqz.googlegroups.com>
<h2o603c8f071004271755v3e56a408hbd23b5c355058aa@mail.gmail.com>
<4BDB5ECE.4010607@agliodbs.com>
<y2gdcc563d11005010913w3a24a73dl9e6c5e0ae174f730@mail.gmail.com>
<AANLkTimzCzICjjgrhGukmYX8adpzRDYhsEqD9s_80Dhy@mail.gmail.com>
<m2mdcc563d11005011217nb578578bz68c99276ceaf0e45@mail.gmail.com>
On Sat, May 1, 2010 at 1:17 PM, Scott Marlowe <scott.marlowe@gmail.com> wrote:
> On Sat, May 1, 2010 at 1:08 PM, Robert Haas <robertmhaas@gmail.com> wrote:
>> On Sat, May 1, 2010 at 12:13 PM, Scott Marlowe <scott.marlowe@gmail.com> wrote:
>>> On Fri, Apr 30, 2010 at 4:50 PM, Josh Berkus <josh@agliodbs.com> wrote:
>>>> Which is the opposite of my experience; currently we have several
>>>> clients who have issues which required more-frequent analyzes on
>>>> specific tables. Before 8.4, vacuuming more frequently, especially on
>>>> large tables, was very costly; vacuum takes a lot of I/O and CPU. Even
>>>> with 8.4 it's not something you want to increase without thinking about
>>>> the tradeoff
>>>
>>> Actually I would think that statement would be be that before 8.3
>>> vacuum was much more expensive. The changes to vacuum for 8.4 mostly
>>> had to do with moving FSM to disk, making seldom vacuumed tables
>>> easier to keep track of, and making autovac work better in the
>>> presence of long running transactions. The ability to tune IO load
>>> etc was basically unchanged in 8.4.
>>
>> What about http://www.postgresql.org/docs/8.4/static/storage-vm.html ?
>
> That really only has an effect no tables that aren't updated very
> often. Unless you've got a whole bunch of those, it's not that big of
> a deal.
sigh, s/ no / on /
Anyway, my real point was that the big improvements that made vacuum
so much better came in 8.3, with HOT updates and multi-threaded vacuum
(that might have shown up in 8.2 even) 8.3 was a huge improvement and
compelling upgrade from 8.1 for me.
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To: pgsql-performance@postgresql.org
Cc: scott.marlowe@gmail.com, robertmhaas@gmail.com, josh@agliodbs.com, richard.branton@ca.com
Subject: Re: autovacuum strategy / parameters
In-Reply-To: <i2gdcc563d11005011219wd97f29a3l4eec3eefbed07a77@mail.gmail.com>
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