MySQL is a very interesting beast to deal with – both junior developers and expert database administrators working with the RDBMS know that the world of MySQL offers a breadth of opportunities not found anywhere else: people can choose a storage engine to use from a list of powerful storage engines, the RDBMS can be heavily optimized to serve very specific needs, MySQL has multiple specific types of tools and operations in place that can be used to optimize query performance, etc.
One of the most frequent causes of headaches for database administrators for ages are queries and their optimization