The internal "bike shop" test project uses MySQL with Hibernate. If after creating the project you change the JPA provider, e.g. as follows:
... then in persistence.xml, the provider is configured to update the database schema, e.g.:
This is not desirable if project has any DBRE-managed entities, as by definition the corresponding tables should never be updated. It would be better for the above property to be set so as not to update the schema (i.e. "none" in the case of EclipseLink). While this would mean not creating or updating the required tables for non-DBRE entities, this is the lesser of two evils.