MySQL is the most popular open source Relational Database Management System (RDBMS) that uses Structured Query Language (SQL).

A single poorly-designed SQL query will pose a significant threat to the overall performance of your application. Therefore, optimizing query performance is essential. MySQL comes with tools that help us in the optimization of queries. Read here the most important and useful tips to improve MySQL Query for speed and performance.
https://www.bridge-global.com/blog/tips-to-improve-mysql-query-performance/