You can think of the data in your database as being at the center of a set of rings, as illustrated by the following figure:

The outermost ring is the Internet. This is the outside world. If we are running a business, this is where our customers are. It's also where many attacks originate.

The next two rings are our Internal Network and the Building where our MariaDB database server is located. Internal corporate networks can span several buildings, but if we're a small business or a hobbyist, the network might just be a single building or even a room or two inside a building or a house. We need to be as careful regarding the security on our internal network as we are on the external Internet, especially seeing as more attacks come from inside networks than from the outside world.

Physical security is also important. If an attacker can simply walk in and take the server or computer where our MariaDB database is present and walk out with it, none of our network and other security...