On Wed, 2009-01-28 at 22:47 +0200, Heikki Linnakangas wrote: > Simon Riggs wrote: > > The essential choice is "What would you like the max failover time to > > be?". Some users want one server with max 5 mins behind, some want two > > servers, one with 0 seconds behind, one with 12 hours behind > > It's not quite that simple.
In this case, yes it is. > Setting max_standby_delay=5mins means that > you're willing to wait 5 minutes for each query to die. Which means that > in worst case you have to stop for 5 minutes at every single vacuum > record, and fall behind much more than 5 minutes. That's not how this patch works. > You could make it more like that by tracking the timestamps in commit > records Which is what we do. > It should also be noted that the control functions allow you to connect > to the database and manually pause/resume the replay. So you can for > example set max_standby_delay=0 during the day, but pause the replay > manually before starting a nightly report. Yes, thank you for bringing balance to the discussions. Please everybody read this before commenting further. http://wiki.postgresql.org/wiki/Hot_Standby#Usage -- 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
