[Mysql]
sudo apt-get purge mysql-server
sudo apt-get purge mysql-common


[MariaDB]
sudo apt-get purge mariadb-server
sudo apt-get purge mariadb-common


[공용작업]
sudo rm -rf /var/log/mysql
sudo rm -rf /var/log/mysql.*
sudo rm -rf /var/lib/mysql
sudo rm -rf /etc/mysql