Which statement correctly contrasts normalization and denormalization in MDC3?

• A. Normalization increases redundancy.
• B. Denormalization always improves write performance.
• C. Normalization reduces redundancy; Denormalization introduces redundancy for read performance; MDC3 uses normalization for data integrity and selective denormalization when reporting demands.
• D. Denormalization eliminates data integrity concerns.

Answer: (C)

The main concept here is the trade-off between normalization and denormalization and how MDC3 uses them. Normalization reduces redundancy by structuring data into related tables and using keys to link them, which helps prevent update anomalies and preserves data integrity. Denormalization, on the other hand, adds controlled redundancy to speed up reads and reporting by avoiding complex joins and queries. In MDC3, the system relies on normalization to maintain data integrity and applies selective denormalization only when reporting demands require faster or simpler access. This captures the idea that normalization keeps data clean, while denormalization is used strategically to improve read performance. The other statements don’t fit: normalization does not increase redundancy; denormalization does not always improve write performance (it can complicate updates); and denormalization does not eliminate data integrity concerns.