Interview Question

What is normalization?

Normalization structures relations around keys and dependencies.

💡 Concept ✅ Quick Revision 🗃️ SQL

Answer

Normalization organizes relational data to reduce harmful redundancy and dependency problems. • Relations are decomposed according to keys and functional dependencies. • A good decomposition should preserve required information and preferably important dependencies. • Normalization is a design method, not a command that automatically improves every workload.

💡 SQL Example

CREATE TABLE departments (department_id integer PRIMARY KEY, name text UNIQUE NOT NULL);

Result

Department facts are stored once

⚡ Quick Revision

Normalization structures relations around keys and dependencies.