Database Normalization

Database Normalization

Database normalization is the process of organizing the fields and tables of a database to minimize data redundancy and dependency.

First Normal Form (1NF)

• Each table cell must contain a single value.
• Each column must have a unique name.
• No repeating groups or arrays are allowed.
• Each row must have a unique combination of values.

Second Normal Form (2NF)

• A table is in 2NF if it is in 1NF and all non-prime attributes are fully functional dependent on the primary key.
• A non-prime attribute is fully functional dependent on the primary key if its value depends on the primary key.
• 2NF eliminates partial dependencies.

Third Normal Form (3NF)

• A table is in 3NF if it is in 2NF and there are no transitive dependencies.
• A transitive dependency occurs when a non-prime attribute depends on another non-prime attribute.
• 3NF eliminates transitive dependencies.

Key points to remember:

• Normalization helps to:
  • Eliminate data redundancy
  • Reduce data anomalies
  • Improve data integrity
• Denormalization can be used to improve performance in certain situations.