> I needed know if is possible to assign all SYSDBA's privileges to
> another user and if is possible how I can do?

No, but you do not need it, because most objects (tables, procedures, etc)
have its owner who has rights to manipulate data/metadata of that object.

You need SYSDBA only to add/alter users, and even this requirement
can be easily changed.

> Again I can prohibit access at my database from another SYSDBA ?

You can create role SYSDBA, which prevents user SYSDBA from logging
into the database (provided that nobody has direct access to database file itself)

Ivan
http://www.volny.cz/iprenosil/interbase/