Have you worked with data denormalization in databases?

Data denormalization is the process of intentionally duplicating data in a database to improve read performance at the cost of increased data volume and potentially more complex updates.

In my practice, I used denormalization when I needed to speed up queries in systems with a large number of JOIN operations. For example, instead of joining order and customer tables each time, I added fields with the customer's name and contact information to the orders table. This reduced the number of JOINs and sped up reporting.

Example in SQL:

-- Normalized structure
SELECT orders.id, customers.name
FROM orders
JOIN customers ON orders.customer_id = customers.id;

-- Denormalized structure
-- The orders table has a customer_name field, updated when customer data changes
SELECT id, customer_name FROM orders;

This approach is useful in systems with high read load and relatively infrequent updates.