Neverthless, the models do influence how you can manage the information. Relational models are solid and proven. But then we also have Treel models (in LDAP), and general trend towards shared information model by multiple applications. Approach of SAP, PeopleSoft etc. is to hide even the relational model (with their supplied schemas), and provide an application layer for integration - but most such integration is custom-made.
In IMV, we believe that graph is the "right model" of data (and metadata), and like LDAP's tree model, it is the next generation model. Views are integral to these, and the actual mappings to underlying Database layers could be hidden. Query mechanisms in graph data will have to be developed, and may not even be optimal. How exactly DB technology can be used as underlying layer is yet to be seen. LDAP itself has not been deployed off DB's; most ldap servers use DBMs (i.e. table model of data).