On Thu, Oct 6, 2011 at 12:44 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Robert Haas <robertmh...@gmail.com> writes: >> I'm not entirely sure I understand the rationale, though. I mean, if >> very little has happened since the last checkpoint, then the >> checkpoint will be very cheap. In the totally degenerate case Fujii >> Masao is reporting, where absolutely nothing has happened, it should >> be basically free. We'll loop through a whole bunch of things, decide >> there's nothing to fsync, and call it a day. > > I think the point is that a totally idle database should not continue to > emit WAL, not even at a slow rate. There are also power-consumption > objections to allowing the checkpoint process to fire up to no purpose.
Hmm, OK. I still think it's a little funny to say that checkpoint_timeout will force a checkpoint every N minutes except when it doesn't, but maybe there's no real harm in that as long as we document it properly. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
