Обсуждение: About using drivers....

On Tue, 9 Mar 2004, [iso-8859-1] Armando Ba�uelos wrote:

> I have a question that probably must be a FAQ... I didn't see in the
> documentation on in other pages if the driver is always backward
> compatible with any version of the PostgreSQL server... for example if I
> have a server 7.3.3 and I have the driver pg74.1jdbc3.jar (the lastest)
> it is fully backward compatible with that server (I see in the server
> console a FATAL: unsupported frontend protocol ... but the driver seem
> to be working in the client side) or I must use the pg73jdbc3.jar
> instead.  Any information would be appreciated Thankx!!!! Armando
>

In the 7.4 driver and server a new communication protocol was added, so
the 7.4 driver tries to connect using the new V3 protocol and if that
fails it falls back to the V2 protocol, so what you are seeing is all the
initial V3 protocol failures, to prevent this from happening you can add a
compatible=7.3 parameter to your connection url like so:

jdbc:postgresql://localhost:5432/mydb?compatible=7.3

This will make the initial connection attempt use the V2 protocol.

Kris Jurka