BTW, What I'd like to see as a very first patch first is to change the
current poll loops in walreceiver and walsender to, well, not poll.
That's a requirement for synchronous replication, is very useful on its
own, and requires a some design and implementation effort to get right.
It would be nice to get that out of the way before/during we discuss the
more user-visible behavior.
-- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com