In which cases is denormalization in database structure advisable?

Denormalization in a database is advisable in the following cases:

• Improving read performance: When queries often require joining multiple tables, denormalization helps reduce the number of JOIN operations.
• Optimization for specific scenarios: For example, in analytical systems or reporting systems where data retrieval speed is important.
• Simplifying queries: Denormalization can make the data structure more understandable and convenient for certain applications.

However, it also increases data redundancy and the complexity of maintaining data integrity. Therefore, denormalization is used when the performance benefits outweigh the risks and costs of data updates.

Example: instead of storing a user's address in a separate table, you can add address fields directly to the users table if addresses rarely change and reading is frequent.