Why would a database be denormalized?

A.
To ensure data integrity.

B.
To increase processing efficiency.

C.
To prevent duplication of data.

D.
To save storage space.

Explanation:
Denormalization is the process of attempting to optimize the performance of data
storage by adding redundant data. It is necessary because current DBMSs are not fully relational.
A fully relational DBMS would be able to preserve full normalization at the logical level, while

allowing it to be mapped to performance-tuned physical level. Database designers often justify
denormalization on performance issues, but they should note that logical denormalization can
easily break the consistency of the database, one of the all-important ACID properties. However, a
designer can achieve the performance benefits while retaining consistency by performing
denormalization at a physical level; such denormalization is often called caching.