In databases, what is data normalization?

• A. Organizing data to reduce redundancy and improve integrity by structuring tables and relationships.
• B. Changing data to a standard format for display.
• C. Deleting all duplicates from all records.
• D. Encrypting data at rest.

Answer: (A)

Data normalization is the process of organizing data in a database to reduce redundancy and improve data integrity by structuring tables and relationships. This means splitting information into related, smaller tables and using keys to link them so each fact is stored once. For example, keep a Customers table with customer_id, name, and address, and a separate Orders table with order_id, order_date, and customer_id; the two tables connect through the customer_id. If a customer’s address changes, you update it in one place, which prevents inconsistencies and anomalies that can happen when the same data is repeated in multiple records. Normalization guides how data dependencies are arranged to keep data consistent, and it’s different from simply formatting data for display, deleting duplicates in bulk, or encrypting data at rest.