Explanation:
Inconsistent database backups are required for the database available 24 hours a day, 7 days a week. An inconsistent backup is a backup of one or more database files that you make while the database is open or after the database has shut down abnormally. Whether you make consistent or inconsistent backups depends on a number of factors. If your database must be open and available all the time, then inconsistent backups are your only option. If there are recurring periods of minimal use, then you may decide to take regular consistent backups of the whole database and supplement them with online backups of often-used table spaces. Incorrect Answer:
1: User-managed backups will not provide 24 hours a day, 7 days a week database availability.
2: Database backup should be inconsistent, not partial.
3: Database backup should be inconsistent. A consistent backup is a backup of one or more database files that you make after the database has been closed with a clean SHUTDOWN command. Unlike an inconsistent backup, a consistent, whole database backup does not require recovery after it is restored.
Reference:
OCP Oracle 9i Database: Fundamentals II Exam Guide, Rama Velpuri, p. 187-189
Chapter 8: Configuring the Database Archive Mode

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