Re: 7.4 Checkpoint Question - Mailing list pgsql-performance

From Andrew Sullivan
Subject Re: 7.4 Checkpoint Question
Date
Msg-id 20071129160219.GJ6226@crankycanuck.ca
Whole thread Raw
In response to 7.4 Checkpoint Question  (Brad Nicholson <bnichols@ca.afilias.info>)
List pgsql-performance
On Thu, Nov 29, 2007 at 10:10:54AM -0500, Brad Nicholson wrote:
> This is a _really _low volume system, less than 500 writes/hour.  Normal
> operation sees checkpoint related spikes of around 200-300 milliseconds.
> We always checkpoint at the checkpoint timeout (every 5 minutes).
> During this one checkpoint, I'm seeing transactions running 2-3 seconds.
> During this time, writes are < 5/minute.

> What gives?

pg_dump?  Remember that it has special locks approximately equivalent
(actually eq?  I forget) with SERIALIZABLE mode, which makes things rather
different.

A

--
Andrew Sullivan
Old sigs will return after re-constitution of blue smoke

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