>
> I have a question about the owner change with gbak. When I set the
> owner of the database to a new user and revoke the privileges from the
> sysdba I can still use gbak to change the owner back to sysdba. I don't
> want my customers which have the database from our software installed
> on their computers to set up a clean firebird server and do a backup of
> the database to change the owner back to sysdba. Is there any chance to
> protect the delivered database from this procedure?
>

restoring a database as USERA or SYSDBA after all or much of it it has been
created by USERB does not set all the object ownership to USERSA.
(just in case you think that's what's happening)

and I think you'd be advised to read this paper,

http://www.firebirdsql.org/manual/fbmetasecur.html

Alan