Squash 1.21 release is scheduled for late December 2019. After installing this 1.21 version - or for any version to be released in the future - two database management systems will be officially covered by Squash Support: PostgreSQL and Maria DB. For MySQL users, if you choose to upgrade Squash 1.21, MySQL will not be supported anymore by Squash Support. Following the acquisition of MySQL by Sun Microsystems and Oracle, a MySQL community fork has been created: MariaDB. The governance of the MariaDB project is provided by the MariaDB Foundation. Thus, it ensures that the Database management systems will remain free. You will be able to upgrade from MySQL to MariaDB by consulting the documentation here. For the sake of completeness, if you use 1.20 Squash version or older versions, MySQL will be supported by Squash team.