Query cancellation and OOB

   It just occurred to me, while browsing through the last hacker's
digest, that OOB might be more trouble than it's worth.  What about
having the Postmaster listen on a second socket as an alternative?
Certain commands could be issued there, outside of the main connection
(possibly even via UDP) as one-shot deals (not requiring a persistent
connection) and the postmaster could pass the information on to the
appropriate backend in a nice, intrusive fashion. :)

-Brandon :)