OCA Oracle Database 11g Administration I Exam Guide (Exam 1Z0-052)

11 Managing Undo Data

CERTIFICATION OBJECTIVES

11.01 Explain the Purpose of Undo

11.02 Understand How Transactions Generate Undo

11.03 Manage Undo

Two-Minute Drill

Self Test

Chapter 10 described what happens in memory, and on disk, when you execute INSERT, UPDATE, or DELETE statements—the manner in which changed data is written to blocks of table and index segments, and the old version of the data is written out to blocks of an undo segment. It also covered the theory behind this, summarized as the ACID test, which every relational database must ...