Tableau offers the MySQL connector, a supplemental library that also works for MariaDB (MariaDB is an offshoot from MySQL). You can connect to MariaDB directly using Tableau's MySQL connector.
Please select MySQL under Connect- To a Server. Next in the MySQL window please input the following information:
Server= hostname
Username= username
Password= password
Make sure to select the Require SSL box and the No custom configuration file specified (click to change)... checkbox:
Next in the Configure SSL Certificate window, please select Use the following custom SSL certificate file and Browse to input the path on your local hard drive to your ca-cert.pem file. Please contact research@hbs.edu if you do not have this certificate file. Then click OK.
Now you may Sign in in the MySQL window and connect to MariaDB.