• allow it by adding into /etc/mysql/my.cnf:
    [mysqld]
    federated
  • restart mysql 🙂 using “sudo service mysql restart”
  • about federated tables:
    • if you want to create only one or two tables per remote server use just CREATE TABLE with login credentials in CONNECTION part
    • for more tables it is more convenient to use CREATE SERVER first (with PASSWORD of course) and use ‘server/tablename’ in CONNECTION part in CREATE TABLE
    • of course you must have proper grants on all remote databases to allow selects from federated engine
  • it works like a magic and you can select from remote tables without any problems BUT – MySQL so far (2017/01) does not implement operations like “SELECT MINUS SELECT” or “SELECT INTERSECT SELECT” so if you wanted to use FEDERATED engine for data comparison you have to now construct complicated joins and where conditions to get some usable results…