If you've found yourself in the MySQL space at least for a little while, chances are that you have heard about one of its well-known files: my.cnf. my.cnf is a configuration file exclusive to MySQL and all of its flavors and it's widely regarded as the "go-to" file whenever MySQL configuration errors occur. Sure, we can set up a couple of settings when we start MySQL with the "--" options, but that doesn't do much - it's much more effective to set the settings inside of the configuration file instead.
Why Does MySQL Need a Configuration File?
First things first, we will look into why MySQL needs a configuration file in the first place. After all, MySQL is a powerful beast as-is, right? Well, not quite. You see, these days MySQL is running on a very wide variety of infrastructures and database servers - some servers might have 20TB of hard drive space and 256GB of RAM allocated to them, others - like small virtual private servers or the like - might only have 2GB of space and 256MB of RAM. The difference here is huge and the primary purpose of configuration files in this scenario is to provide an "endpoint" for MySQL DBAs and developers to configure it according to their requirements.