Re: Checkpoint Tuning Question - Mailing list pgsql-general

From Tom Lane
Subject Re: Checkpoint Tuning Question
Date
Msg-id 25426.1247078683@sss.pgh.pa.us
Whole thread Raw
In response to Re: Checkpoint Tuning Question  (Dan Armbrust <daniel.armbrust.list@gmail.com>)
Responses Re: Checkpoint Tuning Question
List pgsql-general
Dan Armbrust <daniel.armbrust.list@gmail.com> writes:
> On Wed, Jul 8, 2009 at 1:23 PM, Tom Lane<tgl@sss.pgh.pa.us> wrote:
>> Well, you could increase both those settings so as to put the
>> checkpoints further apart, and/or increase checkpoint_completion_target
>> to spread the checkpoint I/O over a larger fraction of the cycle.

> Wouldn't increasing the length between checkpoints result in the
> checkpoint process taking even longer to complete?

You don't really care how long it takes.  What you want is for it not to
be chewing a bigger fraction of your I/O bandwidth than you can spare.
Hence, you want it to take longer.  Trying to shorten it is just going
to make the spike worse.

            regards, tom lane

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