Explanation:
Time-based recovery will stop after the database has committed all changes up to the specified point in time. If uncommitted data was written in order to supply the database with all committed information to the time named, then the uncommitted transaction data will be rolled back before the recovery ends. You might use changes or dropped a table, and you know approximately what time the mishap occurred; a redo log that is not multiplexed is discovered to be corrupt, and you know what time the redo log was archived.
Incorrect Answers:
1: If recovery is stopped by entering CANCEL at the recovery prompt, it's cancel-based recovery.
2: Recovery is stopped by pressing at <CTL-C> the recovery prompt is not time-based recovery, but just user interrupted recovery of any type.
4: If recovery is stopped when the database has committed all changes up to the specified system changes number (SCN), it is change-based incomplete recovery.
5: In the situation when recovery is stopped when the specified method of recovery (CANCEL, TIME, or CHANGE), it is incomplete recovery, but not definitely time-based recovery: it can be also cancel-based and change-based recovery.
Oracle 8, DBA Certification Exam Guide, Jason S. Couchman, p. 703-706
Chapter 15: Advanced Topics in Data Recovery

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