MonographDB is a propietary distributed DBMS based on MariaDB that uses a custom storage manager that stores data on a Cassandra cluster.
Relational
SQL
N-ary Storage Model (Row/Record)
Shared-Disk
http://monographdata.com/
http://monographdata.com/monographdb/quick-start/
MonographDB, Inc.
CN
2021
Commercial
Cassandra, MariaDB
MySQL
Hosted
Proprietary