One of the primary security principles is authentication.
Authentication is the process of confirming the identity of a user. Users access the database by way of user accounts. In order to successfully log in to a database, a user must pass through some form of authentication, often by way of a user account name and password. To review what we've learned in previous chapters, there are two major default administrative accounts in Oracle called SYS and SYSTEM. The SYS account is the highest administrative account available. It owns the data dictionary and has the power to do any type of administrative activity. The SYSTEM account is comparable in terms of authority, but does not own the data dictionary. SYSTEM is often used by DBAs to administer the database, although SYS is used in certain cases, such as starting and stopping the database. We can, however, create other database user accounts with varying degrees of access.
Many of the following examples...