Denormalization in databases is an optimization technique for improving the performance of certain queries. We may need to apply denormalization when the usual normalization incurs some performance penalties. This is often the case when the data volume has changed but we cannot extend the database resources anymore. Denormalization aims to improve query performance in a database. When data volume grows, we may not be able to extend the database resources anymore.

Databases are designed in different ways. Most of the time we can use “school examples”: normalize the database and everything will work just fine. But there are situations that will require another approach. We can remove references to gain more flexibility. But what if we have to improve performance when everything was done by the book? In that case, denormalization is a technique that we should consider. In this article, we’ll discuss the benefits and disadvantages of denormalization and what situations may warrant it.