I installed mariadb using
# yum install mariadb mariadb-sever
Then on running:
# systemctl start mariadb
I got:
# Failed to start mariadb.service: Unit mariadb.service not found
& on running:
# systemctl restart mysqld
I got:
# Failed to restart mysql.service: Unit mysql.service not found
Simply install, activate at boot + start mysql executable :
yum install mariadb mariadb-server
systemctl enable --now mariadb.service