From: | Robert Haas <robertmhaas(at)gmail(dot)com> |
---|---|
To: | Aidan Van Dyk <aidan(at)highrise(dot)ca> |
Cc: | Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>, David Fetter <david(at)fetter(dot)org>, PG Hackers <pgsql-hackers(at)postgresql(dot)org>, jkshah(at)gmail(dot)com |
Subject: | Re: [WIP] Double-write with Fast Checksums |
Date: | 2012-01-11 15:16:59 |
Message-ID: | CA+Tgmoak-0TaEVubypzF05bgFk7nMeRLzyoQXxiD_ykUwN-w2w@mail.gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
On Wed, Jan 11, 2012 at 9:47 AM, Aidan Van Dyk <aidan(at)highrise(dot)ca> wrote:
> It does this by moving the FPW/IO penalty from the commit time of a
> backend dirtying the buffer first, to the eviction time of a backend
> evicting a dirty buffer. And if you're lucky enough that the
> background writer is the only one writing dirty buffers, you'll see
> lots of improvements in your performance (equivilent of running with
> current FPW off). But I have a feeling that many of us see backends
> having to write dirty buffers often enough too that the reduction in
> commit/WAL latency will be offset (hopefully not as much) by increased
> query processing time as backends double-write dirty buffers.
I have that feeling, too. Someone needs to devote some time to
performance testing this stuff.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
From | Date | Subject | |
---|---|---|---|
Next Message | Simon Riggs | 2012-01-11 15:20:24 | Re: [COMMITTERS] pgsql: Send new protocol keepalive messages to standby servers. |
Previous Message | Robert Haas | 2012-01-11 15:15:39 | Re: JSON for PG 9.2 |