B. You cannot insert into a view that contains a CONNECT BY, ORDER BY, or GROUP BY clause.
C. A commit makes pending DML changes permanent. When a checkpoint occurs, DBWR flushes dirty buffers to disk, which is independent of transaction boundaries.
A. A library can be a database object, but is associated with an operating system shared library. PL/SQL programs include procedures, functions, packages, package bodies, and triggers.
D. Using CREATE OR REPLACE PROCEDURE is less typing, but, more importantly, when you drop an object, all privileges granted on that object are dropped as well. When you perform a CREATE OR REPLACE, you do not lose privileges granted on that object.
B. You can create a trigger for just ...