What is the purpose of data normalization in database design?

What is the purpose of data normalization in database design?

• A. To speed up database queries by caching results.
• B. To reduce data redundancy and improve data integrity by organizing data into related tables.
• C. To encrypt data to protect privacy.
• D. To store data in a single large table to simplify access.

Answer: (B)

Data normalization is about organizing data so it’s stored in a structured, logical way that minimizes repetition and keeps related information connected. By splitting data into related tables and using keys to link them, you avoid storing the same fact in multiple places. This means when something changes, you update it in one place, preventing inconsistencies or anomalies that can occur during insertions, updates, or deletions. For example, instead of putting a customer’s address in every order record, you store the address in a separate customer table and reference the customer from orders using a key. This reduces redundancy and ensures data integrity across the database. Caching data for speed, encrypting data for security, or putting everything in one big table do not achieve this structured, redundancy-reducing organization.

Data normalization is about organizing data so it’s stored in a structured, logical way that minimizes repetition and keeps related information connected. By splitting data into related tables and using keys to link them, you avoid storing the same fact in multiple places. This means when something changes, you update it in one place, preventing inconsistencies or anomalies that can occur during insertions, updates, or deletions. For example, instead of putting a customer’s address in every order record, you store the address in a separate customer table and reference the customer from orders using a key. This reduces redundancy and ensures data integrity across the database. Caching data for speed, encrypting data for security, or putting everything in one big table do not achieve this structured, redundancy-reducing organization.