MySQL is a relational database management system. The program runs as a server providing access to the databases. MySQL 's source code is available under terms of the GPL License, that means you can download it and use for free. If you want support and training by the company, you can contact them. You can have it up to date with tools for upgrading and configuring MySQL. Monitoring and adjusting MySQL settings that will tune, scale and maintain performance. In production, you can setting-up and monitor the status of MySQL replication with a simple and easy to use interface. Application code, database schemas and dynamic queries can be tunned up if you experience performance issues.
As a counterpart, MySQL 5.1 has some known bugs in addition to the present in version 5.0. Critical bugs sometimes do not get fixed for long periods of time. Also it shows poor performance when used for Data Warehousing; this is partly due to inability to take advantage of a cluster of CPU cores for processing a single query. Despite all this, this is the preferred database for web developers.