Oracle Database Data Dictionary
Remarks
The data dictionary views, also known as catalog views, let you monitor the state of the database in real time:
The views prefixed with USER_, ALL_, and DBA_, show information about schema objects that are owned by you (USER_), accessible by you (ALL_) or accessible by a user with SYSDBA privilege (DBA_). For example, the view ALL_TABLES shows all tables that you have privileges on.
The V$ views show performance-related information.
The _PRIVS views show privilege information for different combinations of users, roles, and objects.
