Advanced Database and Design.Professor : K.Teng

01) Briefly describe what is role?

• Database provides for easy and controlled privilege management through roles.

• Roles are named groups of related privileges that are granted to users or other roles.

• They are designed to ease the administration of privileges in the database.

02) Briefly describe about characteristics of role?

• Granted to and revoked from users with the same commands used to grant and revoke system privileges.

• May be granted to any user or role. However, a role cannot be granted to itself and cannot be granted circularly.

• Can consist of both system and object privileges

• May be enabled or disabled for each user granted the role

• Can require a password to enable.

• Each role name must be unique among existing usernames and role names

• Are not owned by anyone, are not in any schema

• Have their description stored in the data dictionary.

03) Briefly describe what are benefits of role?

❖ Easier privilege management

❖ Dynamic privilege management

❖ Selective availability of privileges

❖ Can be granted through the operating system

• improved performance

• Easier Privilege Management

Use roles to simplify privilege management. Rather than granting the same set of privileges to several users, you can grant the privileges to a role, and then grant the role to each user.

• Dynamic Privilege Management

If the privileges associated with a role are modified, all the users who are granted the role automatically and immediately acquire the modified privileges.

• Selective Availability of Privileges

Roles can be enabled and disabled to turn privileges on and off temporarily.

Enabling a role can also be used to verify that a user has been granted that role.

• Can be granted Through the Operating System

Operating system commands or utilities can be used to assign roles to users in the database.

• Improved Performance

By disabling roles, there are fewer privileges to verify during statement...