Distinguish between normalization and denormalization and give MDC3 context.

• A. Normalization reduces redundancy by organizing data into related tables with keys.
• B. Denormalization reduces redundancy but can slow writes.
• C. MDC3 uses only normalization and never denormalizes.
• D. Normalization reduces redundancy; Denormalization introduces redundancy for read performance; MDC3 uses normalization for integrity and selective denormalization where reporting demands.

Answer: (D)

Normalization reduces redundancy by organizing data into related tables with keys, which helps enforce data integrity and prevent update anomalies. Denormalization, on the other hand, is the deliberate introduction of redundancy to speed up read performance and simplify queries, though it requires extra storage and careful maintenance to keep data consistent.

In MDC3, the practice is to rely on normalization to ensure data integrity, but when reporting or read-heavy operations demand quicker access, selective denormalization is used. This might mean creating denormalized structures or materialized views that speed up reads while the underlying data remains normalized to preserve consistency.

So, the best choice reflects both parts: normalization to maintain integrity, denormalization to boost read performance when needed, and the MDC3 approach of using normalization plus selective denormalization tailored to reporting needs. The other options cover only part of the picture or misstate MDC3’s approach.