Mariadb repaire
systemctl stop mariadb myisamchk -r -q /var/lib/mysql/*/*.MYI systemctl start mariadb
upgrade mariadb from 5.5.5x to 10 on new installation
How to Upgrade MariaDB 5.5 to MariaDB 10.0 on CentOS 7 mysql_upgrade –protocol=tcp -P 3306 -u root -p https://mariadb.com/kb/en/library/performance-schema-overview/
MySQL Memory allocation
https://dev.mysql.com/doc/refman/8.0/en/memory-use.html