MySQL already has three maintained patchsets or complete forks, and there's no reason to believe any of them would die if Oracle stopped open sourcing MySQL tom

MySQL already has three maintained patchsets or complete forks, and there's no reason to believe any of them would die if Oracle stopped open sourcing MySQL tomorrow. Percona Server and MariaDB are drop-in compatible, while Drizzle went in a different direction. All three projects have some pre-Oracle MySQL developers working on them. Far be it from me to discourage someone from adopting Postgresql instead of MySQL, but there are other options that retain compatibility with mysql-only apps.