Are you planning to take the SY0-501 Security+ exam? If so, you should understand some database concepts that weren't tested in the SY0-401 exam.
See if you can you answer this question?
Q. Database administrators have created a database used by a web application. However, testing shows that the application is taking a significant amount of time accessing data within the database. Which of the following actions is MOST likely to improve the overall performance of a database?
A. Normalization
B. Client-side input validation
C. Server-side input validation
D. Obfuscation
Check out the answer and full explanation here.