Mark,
> Even though they run on the same machine, run the same version of the
> software, and are used by the same applications, they have NO
> interoperability. For now, lets just accept that they need to be on
> separate physical clusters because some need to be able to started and
> stopped while others need to remain running, there are other reasons,
> but one reason will suffice for the discussion.
Well, to answer your original question, I personally would not see your
general idea as useful at all. I admin 9 or 10 PostgreSQL servers
currently and have never run across a need, or even a desire, to do what
you are doing.
In fact, if there's any general demand, it's to go the opposite way:
patches to lock down the system tables and prevent switching databases to
support ISPs and other shared-hosting situations.
For an immediate solution to what you are encountering, have you looked at
pgPool?
--
--Josh
Josh Berkus
Aglio Database Solutions
San Francisco
