Normalization: 1NF, 2NF, 3NF

Discussing data anomalies, functional dependencies, and normalization process: the first normal form, second normal form, third normal form

Table of Contents

· Introduction
· Data Redundancy and Anomalies
∘ Insertion Anomalies
∘ Deletion Anomalies
∘ Update Anomalies
· Normalization Process
∘ 1NF (First Normal Form)
∘ 2NF (Second Normal Form)
∘ 3NF (Third Normal Form)
· Summary
· References

Introduction

The design process is one of the stages in the database life cycle after the data requirements analysis phase is complete. There are two approaches to database design, namely:

1. The top-down design uses the entity-relationship (ER) model. The procedure identifies the entities, followed by the relationships between entities and cardinalities or multiplicities. Each entity — may also be a relationship — is equipped with attributes, primary key, and foreign keys (if any).
2. The bottom-up design does the process of normalization. The method identifies attributes and then groups them into data sets to form relations.