how can the same ejb3 entity code be used with both MySQL and PostgreSQL on the primary keys (integers).The databases already exist - and cannot be modifiedmysql is AUTO_INCREMENTpostgresql is SERIALIt looks like Identity can be used with mysql but not postgresql? Is the only way to fall back to table based sequences?The below link was not much help...http://www.hibernate.org/hib_docs/annotations/reference/en/html/entity.html#entity-mapping-identifier