On the other hand, the second kind of open-source community may have a vendor that controls the project and the project could potentially be “purchased.” MySQL is one such example.

Hibernate 5 has updated dialects for various databases, and MySQL 8 has a special one of its own. Here's an example hibernate.cfg.xml for MySQL 8 for Hibernate 5 apps or newer.

JPA 3 and Hibernate persistence.xml file As developers migrate their old Java Persistence API applications to JPA 3, their progress is often halted when an incorrectly configured JPA 3 persistence.xml ...

With Oracle acquiring Sun Microsystems, it also acquires MySQL, the poster child for open-source applications. (Not to mention Solaris, which Sun says is a larger Linux distribution than Red Hat.