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@@ -69,21 +69,33 @@ Suggest an appropriate recovery technique that a database administrator could us
 
 **A network disconnection occurs while a user is entering a transaction at an ATM bank machine.**
 
-Rollback the transaction.
+Perform a `Backward Recovery` i.e. rollback the transaction.
 
 **A disk drive fails during regular operations while a clerk is entering data about newly registered students.**
 
+If disk mirroring is enabled then one of the secondary nodes can be promoted to become the new primary.
+If mirroring is not enabled, then replacing the drive and restoring from the most recent backup can
+help to restore service. The failed drive can be analyzed to see what bin/transaction logs can be
+recovered so that they can be replayed against the new primary from the time of the last backup.
+
 **The registration office at a university entered an incorrect amount for a student tuition payment. The error was discovered by the financial services department several weeks later.**
 
+Apply a compensating transaction to correct the error.
+
 **The database administrator of a financial institution performed a full database backup, but forgot to activate the journalizing facility. Afterwards, data entry clerks at the financial institution entered transactions for two hours before the database became corrupt. It is discovered that the journalizing facility of the database has not been activated since the backup was made.**
 
+Restore the database to the most recent database backup and apply the after images from the database change log.
+
 ## Question 3
 
 Suggest the most appropriate security measures for each of the situations described below.
 
 **The Western Union bank uses an electronic funds transfer (EFT) system to transmit sensitive financial data between its branches all over the world.**
+
 **A fighter jet simulation company has set up an off-site computer-based training centre for the F35. The company wishes to restrict access to the site to authorized employees. Since each employee's use of the centre is occasional, it does not wish to provide the employees with keys to access the centre.**
+
 **A golf club uses a simple password system to protect its database. The club has created a new Web site to allow both its members and its employees to use the new Web-based system to access and update information. The club finds that it needs a more comprehensive security system to grant different privileges (such as read-only versus create or update) to different users.**
+
 **A training centre at the Northern Technical University has experienced considerable difficulty with unauthorized users who access files and databases by appropriating passwords from legitimate users.**
 
 ## Question 4