On Mon, 2008-09-29 at 08:35 -0400, Tom Lane wrote: > Simon Riggs <[EMAIL PROTECTED]> writes: > > I'm surprised that checkpoint smoothing moves slowly even when it has so > > little to do. > > AFAIK that's operating as designed. The point being that we shouldn't > create any more I/O load than we absolutely have to. > > It's not clear to me that it's a bug for pg_start_backup to take awhile.
> If it is a bug then I'd vote for just making it do an immediate > checkpoint --- that might cause big I/O load but it's hardly likely to > be worse than what will happen when you start taking the subsequent > filesystem backup. It was a clear intention for it to *not* cause a spike if we could avoid it. The idea was if you wanted it to happen quickly then you could do a checkpoint command first... oh well. People might want to I/O limit the backup also, which they can do without needing to let us know. I'm happy to put an option in for this, so we have another function: pg_start_backup(label text, immediate_chkpt boolean). I'll not be rushing to do this though given my current TODO. -- Simon Riggs www.2ndQuadrant.com PostgreSQL Training, Services and Support -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
