Lesson 5: Database Normalization

Objective:

By the end of this lesson, you will be able to:

• Understand the concept of normalization and its importance in database design.
• Explain the principles of normalization.
• Apply normalization techniques to refine the database schema.

Introduction

Normalization

Normalization is a process used to organize data in a database efficiently. It involves structuring a database schema in such a way that reduces data redundancy and dependency, thereby improving data integrity and minimizing anomalies during data manipulation.

Normalization Principles

Normalization is typically divided into different forms, each representing a higher level of normalization. The most common normalization forms are First Normal Form (1NF), Second Normal Form (2NF), and Third Normal Form (3NF). Higher forms such as Boyce-Codd Normal Form (BCNF) and Fourth Normal Form (4NF) may also be considered depending on the specific requirements of the database.

Applying Normalization to Our Inventory Management System

Now that we have implemented the Entity-Relationship Diagram (ERD) for our inventory management system, we can apply normalization principles to refine the database schema and ensure optimal data organization. We’ll start by examining each entity and its attributes to identify potential normalization issues and then proceed to normalize the schema to at least Third Normal Form (3NF).

Normalization of Entities

• Products Entity: We’ll ensure that each attribute contains atomic values (non-decomposable values) and there are no repeating groups. Attributes like Product ID, Name, Description, Price, and Quantity are already atomic, so we’ll focus on eliminating any repeating groups or composite attributes.

• Suppliers Entity: Like the Products entity, we’ll ensure atomicity and eliminate repeating groups. Attributes such as Supplier ID, Name, Contact Information, and Address are already atomic.

• Orders Entity: We’ll examine the attributes to ensure atomicity and eliminate any partial dependencies. Attributes like Order ID, Customer ID, Order Date, Total Price, and Status appear to be atomic, but we’ll verify if any composite attributes or repeating groups exist.

• Customers Entity: We’ll ensure atomicity and eliminate any repeating groups in the attributes. Attributes such as Customer ID, Name, Contact Information, and Address are already atomic.

• Inventory Entity: We’ll review the attributes to ensure atomicity and eliminate any repeating groups. Attributes like Product ID, Quantity on Hand, Reorder Level, and Location should be atomic.

Normalization of Relationships

We’ll also normalize the relationships between entities to ensure that they adhere to normalization principles. This may involve decomposing many-to-many relationships into separate tables or resolving any transitive dependencies.

Outcome

By applying normalization techniques to our inventory management system project, we’ll achieve a database schema that is well-structured, free from data redundancy and anomalies, and optimized for efficient data storage and manipulation. This ensures data integrity and reliability, laying a solid foundation for the development of the inventory management system.