What do you know about data normalization?

Data normalization is the process of organizing data in a database to reduce redundancy and improve data integrity.

Main normal forms:

• First Normal Form (1NF): Atomicity of values in each column. Each attribute should contain only one value.
• Second Normal Form (2NF): Achieved by 1NF and every non-key attribute depends only on the entire composite primary key, not just part of it.
• Third Normal Form (3NF): Achieved by 2NF and no transitive dependencies, meaning non-key attributes do not depend on other non-key attributes.

Additional normal forms include Boyce-Codd Normal Form (BCNF), Fourth Normal Form (4NF), and Fifth Normal Form (5NF), which address more specific dependency issues.

Advantages of normalization:

• Reduction of data redundancy.
• Reduction of anomalies during data insertion, update, and deletion.
• Improvement of data integrity.
• Optimization of database structure.

Disadvantages of normalization:

• It may increase query complexity due to the need for table joins.
• It may reduce performance for certain types of queries.

Normalization is an important aspect of database design to ensure their efficiency and reliability.