Introduction to Database Normalization

Database normalization is the process of organizing data into well-structured tables to reduce data redundancy and prevent data anomalies.

• It divides large tables into smaller related tables and establishes relationships between them.
• It helps maintain data consistency and reduces insertion, update, and deletion anomalies.

• Before Normalization: The table may contain redundant data and suffer from insertion, update, and deletion anomalies.
• After Normalization: The data is divided into logical, related tables to reduce redundancy, prevent anomalies, and improve data consistency.

Need of Normalization

Normalization is used to reduce problems that occur when the same data is stored repeatedly in a database.

• Insertion Anomaly: Occurs when poor table design prevents a new fact from being added without also requiring unrelated or unnecessary data.
• Update Anomaly: Occurs when the same data is stored in multiple rows and must be updated in several places.
• Deletion Anomaly: Occurs when deleting data unintentionally removes other important information.

Features of Database Normalization

• Reduces Data Redundancy: Minimizes unnecessary repetition of the same data.
• Improves Data Consistency: Helps ensure that the same information remains consistent across the database.
• Reduces Data Anomalies: Prevents insertion, update, and deletion problems.
• Improves Database Structure: Organizes data into related tables, making the database easier to maintain.
• Maintains Data Integrity: Helps ensure that relationships and dependencies between data are properly maintained.

Normal Forms in DBMS