Any system that allows individual users to be created must also have some form of user access control. This prevents users from accessing or affecting components that should not be available to them. Access control is critical to establishing system security and contributes to the overall health and safety of a computer system. We see examples of access control in everything from operating systems to web mail accounts. In Oracle, we administer access control using a number of methods, the most primary of which is through the use of privileges.
The first type of privilege we will examine is a
system privilege. System privileges define a class of wide-reaching privileges that affect the ability to do certain operations across the entire database. They do not tend to apply to any single user or object. In our previous login example that generated an error, we found that our new user lacked a system privilege called CREATE SESSION. When we...