Which of the following statements is incorrect regarding differential backups?

• A. They can be more challenging to manage than full backups
• B. They allow for a fast recovery in case of data loss
• C. They require the most recent full backup to restore
• D. They require a complete set of backup files for each restoration

Answer: (D)

The statement regarding differential backups that is considered incorrect is that they require a complete set of backup files for each restoration. This is not the case because differential backups work by saving only the changes made since the last full backup. To perform a restoration, you only need the most recent full backup and the latest differential backup. This process simplifies restoration, as it avoids the need to manage multiple incremental backups that would be required if using incremental backup strategies.

Differential backups are practical because they strike a balance between the speed of recovery and the amount of data backed up. They allow for faster recovery than a full backup alone because, in the event of data loss, you do not have to restore all the data at once; instead, you can restore from the last full backup and the differential backup that contains the changes since that full backup.

While it's true that differential backups can be more challenging to manage than full backups, and they do indeed require the most recent full backup to restore, the statement that they require a complete set of backup files for each restoration is misleading and reflects an incorrect understanding of how differential backups operate.