FAQ - MySQL
What data is in my “/Library/Application Support/appsolute/MAMP PRO/db/mysql56” folder?
This directory contains your pre upgraded MySQL data. When you upgrade from MAMP PRO 4 to MAMP PRO 6 your MySQL is duplicated and named “mysql57”. Your old MySQL will never be used, and when you confident all your hosts have been successfully upgraded to MySQL 5.7 you can delete this directory.