On Sat, 2011-02-19 at 22:52 -0500, Robert Haas wrote: > On Sat, Feb 19, 2011 at 3:28 AM, Simon Riggs <si...@2ndquadrant.com> wrote: > > First, we should be clear to explain that you are referring to the fact > > that the request > > synchronous_commit = off > > synchronous_replication = on > > makes no sense in the way the replication system is currently designed, > > even though it is a wish-list item to make it work in 9.2+ > > What exactly do you mean by "make it work"? We can either (1) wait > for the local commit and the remote commit (synchronous_commit=on, > synchronous_replication=on), (2) wait for the local commit only > (synchronous_commit=on, synchronous_replication=off), or (3) wait for > neither (synchronous_commit=off, synchronous_replication=off). > There's no fourth possible behavior, AFAICS.
Currently, no, since as we discussed earlier we currently need to fsync WAL locally before it gets sent to standby. > The question is whether synchronous_commit=off, > synchronous_replication=on should behave like (1) or (3) Yes, that is the right question. > You have it as #1; I'm arguing > it should be #3. I realize it's an arguable point; I'm just arguing > for what makes most sense to me. Various comments follow on thread. We can pick this up once we've committed the main patch. -- Simon Riggs http://www.2ndQuadrant.com/books/ PostgreSQL Development, 24x7 Support, Training and Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
