I've recently upgraded Ubuntu from 18.04 LTS to 20.04 LTS on my laptop. One of the great things about doing so, is the ease of updating MariaDB (because I prefer it to MySQL).

As 18.04 was shipped with MariaDB 10.1, and my main development is in PHP using Symfony, I need MySQL 5.7 or MariaDB 10.2 or higher to get the user security working (roles are stored as JSON by default - that's not a data type on earlier versions of the database). Happily, MariaDB provide documentation on how to upgrade from 10.1 to 10.2.

After upgrading Ubuntu, it's even easier than that:
apt install mariadb-server

That saved a lot of removing, ppa updates, updating and installing.