Re: [SQL] unknown error

Herouth Maoz <herouth@oumail.openu.ac.il> writes:
>> The problem is - I cannot start the frontend psql and have following
>> error messages:
>>  Connection to database 'postgres' failed.
>>  Unsupported frontend protocol.

> The protocol that frontend applications (relying on libraries) use has
> changed some time around 6.4. The message probably means that the frontend
> applications are linked with the newer libraries, and your old 6.3.2
> database can't understand them.

Yes, exactly.  You'll need to use a 6.3.2 psql (or at least a 6.3.2
libpq) to talk to your old server.  The newer servers still talk to
old clients, but not vice versa...
        regards, tom lane