Juan Pedro López Sáez wrote:

> Now I'm not sure about the goodness of this schema. I find lots of
> problems when I want to create a new client because I have to shutdown
> the database to create his specific tables.

Why would you have to shutdown?

> I also have problems when I
> have to modify some metadata because it must be done to every client's
> tables.

Well, that's life ;)
You can make scripts that automate it.

> The question is: can anybody tell me if my database design is good
> enough to keep it or should I change it and avoid repeating tables for
> every new client?

Are they all using the same database?
Do those tables' structures differ for different clients?

> Another related issue: sometimes, either if I backup the database or if
> I create lots of new tables (DDL statements), because I need to create
> many new clients, I receive the following exception: lock manager out of
> room.
>
> Why this could be happening and what can I do to solve it?

Can you please explain your problem in a little more detail. I still
don't understand why do you have to create new tables for each client.

--
Milan Babuskov
http://fbexport.sourceforge.net
http://njam.sourceforge.net