91Ó°ÊÓ

Discuss what is meant by each of the following terms: database authorization, access control, data encryption, privileged (system) account, database audit, audit trail. a. Discuss the types of privileges at the account level and those at the relation level.

How is the view mechanism used as an authorization mechanism?

What is meant by revoking a privilege?

Discuss the system of propagation of privileges and the restraints imposed by horizontal and vertical propagation limits.

List the types of privileges available in SQL.

Describe the multilevel relational data model. Define the following terms: apparent key, polyinstantiation, filtering.

What are covert channels? Give an example of a covert channel.