Catalog Views / Data Dictionary Views

Catalog Views / Data Dictionary Views: "The data dictionary views, also known as catalog views, let you monitor the state of the database in real time: * The USER, ALL, and DBA views show information about schema objects that are accessible to you, at different levels of privilege. * The V$ views show performance-related information. * The _PRIVS views show privilege information for different combinations of users, roles, and objects. "