Normalization¶

Database Normalization is a process of organizing database tables to minimize data redundancy and improve data integrity. Let me explain the key concepts and normal forms:

First Normal Form (1NF)¶

Each table cell should contain a single value (atomic)
Each record needs to be unique
Each column should have a single type of data

Second Normal Form (2NF)¶

Must satisfy 1NF
All non-key attributes must fully depend on the primary key
No partial dependencies allowed

Third Normal Form (3NF)¶

Must satisfy 2NF
No transitive dependencies between non-key attributes
Every non-key attribute should depend only on the primary key

Examples¶

Before normalization¶

Customer_Orders
ID | Customer_Name | Customer_Address | Order_Date | Product | Category | Price

After normalization¶

Customers
Customer_ID | Name | Address

Products
Product_ID | Name | Category | Price

Orders
Order_ID | Customer_ID | Product_ID | Order_Date

Benefits of normalization¶

Reduces data redundancy - information is stored only once
Ensures data consistency - updates affect only one record
Makes the database more flexible for future changes
Improves query performance in many cases

However, there are times when denormalization might be preferred¶

When read performance is more critical than write performance
In data warehousing scenarios
When the data structure is relatively stable and won't change often