Which statement about denormalization is true?

Which statement about denormalization is true?

• A. Normalization reduces redundancy.
• B. Denormalization improves write performance.
• C. Normalization eliminates redundancy.
• D. Denormalization optimizes read performance; use-case: data warehousing.

Answer: (D)

Denormalization is the deliberate introduction of redundancy in a database to speed up read operations. In contexts like data warehousing, analytic queries benefit from fewer joins and simpler data access paths, so denormalized designs speed up reads. That’s why the statement about denormalization optimizing read performance, with a use-case in data warehousing, is true. Normalization focuses on reducing redundancy to improve data integrity, so statements about normalization reducing (or eliminating) redundancy describe a different approach, not denormalization. Denormalization can slow down writes because the same information may be duplicated, making updates more complex.

Denormalization is the deliberate introduction of redundancy in a database to speed up read operations. In contexts like data warehousing, analytic queries benefit from fewer joins and simpler data access paths, so denormalized designs speed up reads. That’s why the statement about denormalization optimizing read performance, with a use-case in data warehousing, is true. Normalization focuses on reducing redundancy to improve data integrity, so statements about normalization reducing (or eliminating) redundancy describe a different approach, not denormalization. Denormalization can slow down writes because the same information may be duplicated, making updates more complex.