Explanation:
To end the backup for the USER_DATA table space use the ALTER DATABASE command. If this file was not copied before the instance failure it is not unusable for future recoveries.At the database open fails because the header of the user_data01.dbf is not synchronized with the other database files. Incorrect Answer:
1: This file does not require to be restored and recovered.
5: It is not corrupt.
Reference:
OCP Oracle 9i Database: Fundamentals II Exam Guide, Rama Velpuri, p. 241-244
Chapter 10: User-Managed Backups

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