All, > > For the slave to not interfere with the master at all, we would need to > > delay application of WAL files on each slave until visibility on that > > slave allows the WAL to be applied, but in that case we would have > > long-running transactions delay data visibility of all slave sessions. > > Right, but you could segregate out long-running queries to one slave > server that could be further behind than the others.
I still see having 2 different settings: Synchronous: XID visibility is pushed to the master. Maintains synchronous failover, and users are expected to run *1* master to *1* slave for most installations. Asynchronous: replication stops on the slave whenever minxid gets out of synch. Could have multiple slaves, but noticeable lag between master and slave. -- Josh Berkus PostgreSQL @ Sun San Francisco -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
