A dynamic performance view that has one row for each undo segment in the undo tablespace.
A dynamic performance view that has one row for each active transaction in the database.
A stored query or virtual table. Views don't usually store data but provide access to data in the base tables.
The shared memory structure used by the dispatcher to manage communications between the client and the Oracle server. The shared server processes use virtual circuits to send and receive information to the appropriate dispatcher process.