On Tue, Oct 15, 2013 at 7:26 PM, Andres Freund <and...@2ndquadrant.com> wrote: > On 2013-10-15 10:19:06 -0700, Josh Berkus wrote: >> On 10/15/2013 05:52 AM, Magnus Hagander wrote: >> > But the argument about being friendly for new users should definitely >> > have us change wal_level and max_wal_senders. >> >> +1 for having replication supported out-of-the-box aside from pg_hba.conf. >> >> To put it another way: users are more likely to care about replication >> than they are about IO overhead on a non-replicated server. And for the >> users who care about IO overhead, they are more likely to much about in >> pg.conf *anyway* in order to set a slew of performance-tuning settings. > > But it will hurt people restoring backups using pg_restore -j. I think > people might be rather dissapointed if that slows down by a factor of > three. > > I think we really need to get to the point where we increase the wal > level ondemand...
Yeha, there are really two things. If we can increase wal_level on demand, that would solve one of them. Turning that into a SIGHUP parameter would be great. I have no idea how hard it would be. In theory, couldn't we let it be sighup and then just have do_pg_start_backup() block until all backends have acknowledged that they are on the new WAL level somehow? (Yes, I realize this might be a big simplification, but I'm allowed to hope, no?) The other problem is max_wal_senders. I think that's a much smaller problem - setting that one to 5 or so by default shouldn't have a big impact. But without the wal_level changes, it would also be mostly pointless... -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
