Which statement about normalization and denormalization is true?

• A. Normalization reduces redundancy; denormalization optimizes read performance; use-case: data warehousing.
• B. Denormalization optimizes read performance; use-case: data warehousing.
• C. Normalization eliminates redundancy.
• D. Denormalization enforces referential integrity.

Answer: (B)

Denormalization is used to speed up reads by reducing the number of joins needed to fetch data, which is especially valuable in data warehousing where queries are read-heavy. In normalized designs, data is split into many related tables to minimize redundancy and maintain integrity, but reading across those tables can require costly joins. By denormalizing, you consolidate data into fewer tables or duplicate some values, trading some redundancy for faster query performance. This is why stating that denormalization optimizes read performance and is a common use-case in data warehousing is the most accurate, practical summary.