Explanation:
Prior to Oracle9i, DDL statements were recorded as a set of DML statements on internal tables. It was no simple task to review these DML statements and realize that a DDL operation had been performed. You could almost forget this when trying to determine the actual DDL statement that sourced these DML statements. Oracle 9i records the original DDL statement in the redo logs, and LogMiner lists this DDL statement followed by the set of generated DML statements. When you query V$LOGMNR_CONTENTS, you can see DDL under the OPERATION column, and the DDL statement itself under the SQL_REDO column.
Incorrect Answers:
2: This view does not provide the requested information. There are no USERNAME, OPERATION, SQL_REDO and OPERATION columns in this view.
3: You don’t need to wait until after hours, shutdown database to retrieve this information. The V$LOGMNR_CONTENTS dynamic view can be used for this purpose.
4: This task can be done with the V$LOGMNR_CONTENTS dynamic view.
Reference:
OCP Oracle9i Database: New Features for Administrators, Daniel Benjamin, p. 100-110
Chapter 2: Availability Enhancements
Oracle 9i New Features, Robert Freeman, p. 68-72
Chapter 3: New Oracle9i Availability and Recoverability Features

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