We've had a couple of cases recently where we had to advise DBAs to make
manual changes in the system catalogs --- see for instance the 7.4.2
release notes or
http://archives.postgresql.org/pgsql-announce/2005-05/msg00001.php
It'd be nicer if this sort of thing could be handled automatically
by a software update. There are good reasons why it's not trivial,
but having been burnt twice in recent memory, I'm starting to think
it'd be worth setting up a mechanism to handle such changes
automatically. Anyone up for working on it?
regards, tom lane