Normalization is a systematic approach of organizing data in a database to reduce redundancy and improve data integrity. The process involves dividing large tables into smaller, more manageable pieces while ensuring that the relationships between the data are preserved. This section will cover the steps involved in the normalization process, from understanding the basic concepts to applying them in practical scenarios.

• Understand the goals of normalization.
• Learn the steps involved in the normalization process.
• Apply normalization techniques to design efficient database schemas.

Normalization aims to:

1. Eliminate Redundant Data: Reduce data duplication to save storage space and improve data consistency.
2. Ensure Data Integrity: Maintain the accuracy and consistency of data over its lifecycle.
3. Simplify Queries: Make the database easier to query and maintain.

A table is in 1NF if:

• All columns contain atomic (indivisible) values.
• Each column contains values of a single type.
• Each column has a unique name.
• The order in which data is stored does not matter.

Example: Consider a table storing information about students and their courses:

To convert this table to 1NF, we need to ensure that each column contains atomic values:

A table is in 2NF if:

• It is in 1NF.
• All non-key attributes are fully functional dependent on the primary key.

Example: Consider the 1NF table:

To convert this table to 2NF, we need to remove partial dependencies:

A table is in 3NF if:

• It is in 2NF.
• All the attributes are functionally dependent only on the primary key.

Example: Consider the 2NF tables:

If there are no transitive dependencies, the tables are already in 3NF. If there were additional attributes that depended on non-primary key attributes, we would need to further decompose the tables.

A table is in BCNF if:

• It is in 3NF.
• For every functional dependency (X → Y), X should be a super key.

Example: Consider a table with the following structure:

If a course can only be taught by one instructor, we have a dependency Course → Instructor. To satisfy BCNF, we need to decompose the table:

Solution:

1. 1NF:

2. 2NF:

3. 3NF: The tables are already in 3NF as there are no transitive dependencies.

In this section, we covered the normalization process, including the goals of normalization and the steps to achieve different normal forms. By following these steps, you can design efficient and reliable database schemas that minimize redundancy and maintain data integrity.