Enterprise connectivity and integration is managed through Backendless Marketplace where we offer a variety of connectors including DBMS (SQL and NoSQL), Identity Management, MQ and File Storage systems. Backendless connectors establish direct communication with external systems while supporting the same client-side API we offer for our internal system. For instance, you can add Oracle connector to your Backendless backend. That would immediately REST-ify your external database and you can work with it using our published APIs. Similarly, all other external enterprise systems are available for integration.
Enjoy the Connectivity Nirvana