Five recovery techniques are listed below. For each situation described, decide which of the following recovery techniques is most appropriate.

• Backward recovery

• Forward recovery (from latest checkpoint)

• Forward recovery (using backup copy of database)

• Reprocessing transactions

• Switch

a. A phone disconnection occurs while a user is entering a transaction.

b. A disk drive fails during regular operations.

c. A lightning storm causes a power failure.

d. An incorrect amount is entered and posted for a student tuition payment. The error is not discovered for several weeks.

e. Data entry clerks have entered transactions for two hours after a full database backup when the database becomes corrupted. It is discovered that the journalizing facility of the database has not been activated since the backup was made.