"Greg Sabino Mullane" <greg(at)turnstep(dot)com> writes:
>> When connecting from a psql client version xyz to a postgresql server
>> version zyx across the network, what are the rules to follow for
>> assuring compatibility between different versions?
> [snip]
> ... In general, going from an older psql to a newer server will cause
> less problems than going the other way.
One other point is that just connecting and issuing SQL queries should
work, more or less independently of which psql and backend mix you're
using. What is likely to fail is psql's backslash commands, because
those have hard-wired knowledge about the system catalogs, which change
from version to version.
regards, tom lane