On Wed, Jan 18, 2012 at 10:34 AM, Elmar Haneke <elmar@...> wrote:

>
>
> Problems may arise since the Server is not fully compatible - SQL
> working on 1.5 might fail on 2.5.
>

That's an application problem, not related to the fbclient version.
The project goal, generally, is to allow gradual upgrades rather than
requiring that every part of the system be upgraded simultaneously.
So you can use the 1.5 client with a 2.5 server, but you'll get better
performance and possibly some additional features with the 2.5 client.
Similarly, you can use the 2.5 server with a database create by 1.5,
but you'll get better performance and more features if you backup and
restore the database with 2.5 to get the most recent on disk
structure.

Note that there's some limit to the flexibility of the system and that
a new major release (e.g. V3.0) may well break compatibility with very
old versions of the database or client.

Good luck,

Ann