Load testing is crucial for assessing the performance and scalability of SQL databases, especially under high user volumes, which can cause bottlenecks. The process involves simulating realistic user flows and testing infrastructure components, such as databases, in isolation to gain insights into their capabilities and limitations. Grafana k6, a popular tool for performance testing, offers extensions like xk6-sql to support custom protocols and facilitate database load testing. This allows users to plan database architecture and scaling more efficiently. A practical example using k6 involves building a custom k6 binary with SQL extensions, writing JavaScript scripts for database operations like setup, execution, and teardown, and running tests with varying numbers of virtual users to determine the database's handling capacity. The tutorial emphasizes the ease of testing databases separately and invites users to explore k6's community and resources, including Grafana Cloud, which offers a free tier and tailored plans for diverse performance testing needs.