Protection of intellectual property (Schema & SQL code)

I want to develop an application using a database server. But I am concerned
that installing it at client's sites will mean that I am potentially
exposing my intellectual property to theft. (I'm in Asia where this sort of
thing is rife).

Would it be true to say that for all database servers (Oracle, SQLServer,
PostgreSQL, Interbase etc) it is impossible to absolutely protect the
intellectual property contained in the schema design and sql code ( not to
mention the data itself)?

Is it true that a database backup can always be restored on a different
server and thus the administrator can gain complete access to schema, code
and all data?

If there is a difference in this respect on various server types, is there a
"league table" of which offer the best security?

Can security be enforced in some way by compelling each user (including
administrator) to always have a digital certificate even if using a restored
copy on a different server?