Oracle documentation mention Rule Sets to prevent authorized applications to read data from the database. E.g pl/sql developer.
http://docs.oracle.com/cd/B28359_01/server.111/b31222/cfseappr.htm In Oracle Database Vault, you can create a secure application role that you enable with an Oracle Database Vault rule set. Regular Oracle Database secure application roles are enabled by custom PL/SQL procedures. You use secure application roles to prevent users from accessing data from outside an application. This forces users to work within the framework of the application privileges that have been granted to the role.
But I cannot find an example showing how to set this up? Could anyone point me in the right direction?