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Thread: Checkpoints writes

Checkpoints writes

From
Cyril SCETBON
Date:
Hi guys,

What's the way to count the read/write bytes of the checkpoint process
before 8.3 (no pg_stat_bgwriter view :-[ )
I want to distinguish bytes written by checkpoints and others written by
the background process

thanks
--
Cyril SCETBON

Re: Checkpoints writes

From
Greg Smith
Date:
On Thu, 7 Aug 2008, Cyril SCETBON wrote:

> What's the way to count the read/write bytes of the checkpoint process
> before 8.3 (no pg_stat_bgwriter view :-[ ) I want to distinguish bytes
> written by checkpoints and others written by the background process

The reason that view was added was because it's really hard to figure that
out in earlier versions.  Theoretically you could have some operating
system level program that tracked I/O on a per-process basis, noting which
one was the background writer process and counting those separately.  I
found it easier to work on adding the counters instead.

It's not really complete, but I did have a functional prototype of a
pg_stat_bgwriter implementation that worked against 8.2 if that helps you
any: http://www.westnet.com/~gsmith/content/postgresql/perfmon82.htm

--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD

Re: Checkpoints writes

From
Cyril SCETBON
Date:

Greg Smith wrote:
> On Thu, 7 Aug 2008, Cyril SCETBON wrote:
>
>> What's the way to count the read/write bytes of the checkpoint
>> process before 8.3 (no pg_stat_bgwriter view :-[ ) I want to
>> distinguish bytes written by checkpoints and others written by the
>> background process
>
> The reason that view was added was because it's really hard to figure
> that out in earlier versions.  Theoretically you could have some
> operating system level program that tracked I/O on a per-process
> basis, noting which one was the background writer process and counting
> those separately.  I found it easier to work on adding the counters
> instead.
>
> It's not really complete, but I did have a functional prototype of a
> pg_stat_bgwriter implementation that worked against 8.2 if that helps
> you any: http://www.westnet.com/~gsmith/content/postgresql/perfmon82.htm
a really great job greg. I'll test it.

Thanks
>
> --
> * Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD
>

--
Cyril SCETBON