"Oliver Elphick" <olly@lfix.co.uk> writes:
> Is it possible to use libpq.so.2.0 to query a remote database whose
> server is running PostgreSQL 6.3?
No. That's why we changed the major version number, to make it
easier to keep an old libpq around if you need it.
> What would be the consequences of
> using libpq.so.1 to query a 6.4 server?
Should work fine. The new server still handles the old FE/BE protocol.
(Or at least, it's supposed to ... I haven't tested that lately, but
I believe Tatsuo-san did.)
regards, tom lane