On Thu, 2008-12-11 at 17:07 +0200, Heikki Linnakangas wrote: > Simon Riggs wrote: > > On Thu, 2008-12-11 at 09:27 -0500, Aidan Van Dyk wrote: > > > >> But "catchup" *has* to be *done* before PostgreSQL can enter "sync rep". > > > > Not true. Please reread the thread where Heikki questions that and I > > reply. This was Fujii-san's idea, which I now agree with. > > I think the confusion here is about what exactly "sync rep" means in > this situation. It's true that you can start streaming the WAL before > the standby has fully caught up.
Yep. > But from the client's point of view, > there's not much point in streaming the log *synchronously* and making > the client to wait for the acknowledment from the standby, if the > acknowledgment from the standby that WAL has be streamed up to point X, > doesn't actually guarantee that the slave can recover all the way to > that point. I disagree. This morning I showed it was possible, given the synchronisation I outlined. There is a slight relaxation of that in the current proposal, so you need to take that up if you see any problem there. -- Simon Riggs www.2ndQuadrant.com PostgreSQL Training, Services and Support -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
