1. A method for accessing data, comprising: defining a composite data model, wherein the composite data model describes a federated database composed from database components provided by a first entity and at least one component provided by a seconded entity that is described in an externalized data model; composing a query to retrieve data from the federated database defined by the composite data model; providing the query to a runtime component configured to execute the composite query against the federated database; determining a fee amount charged to the first entity for accessing at least one element of data included in the query results originating from a database component provided by the second entity.