I don't know how many years of exp. you have using Oracle databases. Cheaper is not always the better. Oracle has been introducing very rapid change in their database, adding new features and flexibility to use different data models which databases like MariaDB is far from. If they are not able to use Oracle DB properly they need to look deep into their application structure, programming practice and data models. Unless they sort out these problems they will run into the same problems with MariaDB as they have with Oracle. Any database migration motivated by cost alone will eventually fail.
Biting the hand that feeds IT
