Palle Girgensohn <girgen@pingpong.net> writes:
> Surely, I can use an postgresql 7.2 client to connect to a 7.3.x or 7.4
> server, right?
It will work unless the client makes now-obsolete assumptions about the
layout of the system catalogs.
As an example, a 7.2 psql will work for issuing regular user queries
against a newer server, but its catalog inquiry stuff (\d and friends)
will work poorly or not at all.
regards, tom lane