Samuel Johnson: Dictionary
This chapter describes the central set of read-only reference tables and views of each Oracle database, known collectively as the data dictionary. The chapter includes:
Not only is the data dictionary central to every Oracle database, it is an important tool for all users, from end users to application designers and database administrators. Even beginning users can benefit from understanding and using the data dictionary. However, no user should ever alter (update, delete, or insert) any rows or objects in the data dictionary; such activity can compromise data integrity.