How can tables be denormalized?

Denormalization is the process of intentionally introducing redundancy into a database structure to improve read performance at the cost of increased data volume and more complex updates.

Main methods of table denormalization:

• Adding redundant columns: for example, storing computed values or aggregates directly in the table.
• Joining tables: creating a single table with repeated data instead of multiple related tables.
• Copying data: duplicating frequently used data from related tables to speed up queries.

Example: instead of two tables orders and customers with a foreign key, you can add fields with the customer's name and address to orders to avoid JOINs during reading.

It is important to remember that denormalization complicates data maintenance, requires additional logic for synchronization, and updates of redundant data.