MySQL + SQL · Lesson 25
Normalization in DBMS
What is Normalization?
Normalization is the process of organizing tables to reduce redundancy and avoid anomalies (insert, update, delete problems). It splits large tables into smaller related ones.
Why Normalize?
- Removes duplicate data.
- Prevents update anomalies (changing data in many places).
- Keeps data consistent and clean.
Normal Forms (Summary)
| Form | Rule |
|---|---|
| 1NF | Atomic values, no repeating groups |
| 2NF | 1NF + no partial dependency |
| 3NF | 2NF + no transitive dependency |
| BCNF | Stronger 3NF — every determinant is a candidate key |
Summary
- Normalization reduces redundancy and anomalies.
- Steps: 1NF → 2NF → 3NF → BCNF.