Database Normalization

Definition

Database Normalization is a process of organizing data in database tables to reduce duplication and improve consistency. It means breaking large tables into smaller, related tables so that each piece of information is stored only once.

What Problem It Solves

It solves issues like:

• Duplicate data stored in multiple rows
• Data inconsistency when updating values
• Difficult maintenance when the same value exists in many places Example problem: If “Mobile” category is stored in 100 rows and later changed to “Smartphone”, you must update all 100 rows manually — which is error-prone.

What Happens If Not Used

Without normalization:

• Data duplication increases
• Updates become inconsistent (some rows updated, some not)
• Database becomes larger and inefficient
• Query results may become unreliable

Easy Wording

Normalization simply means: 👉 “Store each piece of information only once, and connect it properly instead of repeating it everywhere.”