Database Normalization

We now introduce normal forms: Techniques to eliminate redundancy and ensure data integrity in relational databases.

What is Normalization?

Normalization is a systematic process of organizing data in a relational database to minimize redundancy and dependency by dividing large tables into smaller, related tables while maintaining data integrity. Introduced by E.F. Codd, it follows a series of normal forms (NF) that progressively enforce stricter rules.

Benefits: Reduces anomalies during insert/update/delete operations, saves storage, and improves query performance. However, over-normalization can lead to complex joins.

Why Normalize?

Eliminate data redundancy
Prevent update anomalies
Ensure referential integrity

Normal Forms Overview

Explore each normal form in detail through dedicated sub-pages.

Normal Forms

First Normal Form (1NF): Ensures atomicity of values and no repeating groups.
Functional Dependency: Key concept for understanding dependencies in normalization.
Second Normal Form (2NF): Removes partial dependencies (applies to tables with composite keys).
Third Normal Form (3NF): Ensures no transitive dependencies.
Boyce-Codd Normal Form (BCNF): A stronger version of 3NF, ensuring every determinant is a candidate key.
Higher Normal Forms (4NF, 5NF): These deal with more advanced forms of redundancy, such as multivalued dependencies (4NF) and join dependencies (5NF), though they are rarely encountered in most practical applications.

Key Takeaways

Data Integrity

Normal forms prevent anomalies by structuring dependencies properly.

Progressive Refinement

Start with 1NF, aim for 3NF; balance with performance needs.

Practical Application

Essential for schema design in RDBMS like PostgreSQL and MySQL.

"Normalization is the cornerstone of efficient, anomaly-free databases."

Ready to query? Next up: SQL basics.

Previous: ER Diagrams Next: SQL Intro

Resources

Tutorialspoint: Database Normalization

tutorialspoint.com/dbms/database_normalization.htm

Wikipedia: Database Normalization

en.wikipedia.org/wiki/Database_normalization

GeeksforGeeks: Normalization Intro

geeksforgeeks.org/introduction-of-database-normalization/