Advantages of encrypting data stored in the database

1. What are two advantages of encrypting data stored in the database? (2 points)
2. RAID systems typically allow you to replace failed disks without stopping access to the
system. Thus, the data in the failed disk must be rebuilt and written to the replacement disk while
the system is in operation. Which of the RAID levels yields the least amount of interference
between the rebuild and ongoing disk accesses? Explain your answer. (4 points)
3. In the sequential file organization, why is an overflow block used even if there is, at the
moment, only one overflow record? (4 points)