What is normalization in relational databases and why is it used?

What is normalization in relational databases and why is it used?

• A. Normalization merges all data into one table for faster access.
• B. Normalizing organizes data into related tables to reduce redundancy and improve data integrity; uses normal forms and dependency rules.
• C. Normalization uses denormalization to duplicate data for performance.
• D. Normalization is a naming convention for tables.

Answer: (B)

Normalization in relational databases is the process of structuring data to reduce redundancy and ensure logical data dependencies are enforced. It involves organizing data into related tables and applying rules called normal forms, guided by functional dependencies between attributes. By splitting data into separate tables (for example, keeping customer details in one table and listing their orders in another, linked by a customer key), you avoid storing the same information in multiple places and prevent anomalies that occur during updates, inserts, or deletes. Normal forms such as 1NF, 2NF, 3NF, and BCNF provide a systematic way to check and enforce these dependencies. This approach improves data integrity and flexibility, making it easier to update one piece of data without inconsistency and to extend the schema without duplication. The other options describe approaches that are not normalization: merging everything into a single table creates redundancy and anomalies; duplicating data for performance is denormalization; treating normalization as a naming convention misses the structural design aspect.