Re: Load Distributed Checkpoints, take 3

Magnus Hagander wrote:
> On Mon, Jun 25, 2007 at 10:15:07AM +0100, Simon Riggs wrote:
>> As you say, we can put comments in the release notes to advise people of
>> 50% increase in recovery time if the parameters stay the same. That
>> would be balanced by the comment that checkpoints are now considerably
>> smoother than before and more frequent checkpoints are unlikely to be a
>> problem, so it is OK to reduce the parameters from the settings you used
>> in previous releases.
>
> Didn't we already add other featuers that makes recovery much *faster* than
> before?

Yes, we no longer read in a page just to overwrite it with a full page
image.

> In that case, are they faster enugh to neutralise this increased
> time (a guestimate, of course)

It depends a lot on your workload. Under the right circumstances, it
will more than offset any increase caused by LDC, but sometimes it won't
make any difference at all (for example with full_page_writes=off).

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com