Oracle RAS provides a declarative model that enables security policies that encompass not only the business objects being protected but also the principals (users and roles) that have permissions to operate on those business objects. RAS is more secure, scalable, and cost effective than traditional Oracle VPD technology.
With Oracle RAS, application users are authenticated in the application-tier as well as in the database. Irrespective of the data access path, the data security policies are enforced in the database kernel based on the end-user native session in the database. The privileges assigned to the user control the type of operations (select, insert, update and delete) that can be performed on rows and columns of the database objects.