15. A system, comprising a plurality of devices coupled via a network, wherein each device is configured to: receive an abstract query from a requesting entity, wherein the abstract query comprises one or more logical fields defined in a first data abstraction model comprising a plurality of first logical field definitions mapping to physical fields of a first database; wherein the one or more logical fields in the abstract query each have a respective concept code relating corresponding logical field definitions of a plurality of data abstraction models including the first data abstraction model, a second data abstraction model and a third data abstraction model, the second data abstraction model being resident on the device at which the abstract query is received and comprising a plurality of second logical field definitions mapping to physical fields of a second database; modify the abstract query to include one or more of the second logical field definitions from the second data abstraction model based on the respective concept codes; issue the modified abstract query against the second database to retrieve a first set of results for the modified abstract query; send the abstract query to at least one other device of the plurality of devices, the at least one other device comprising the third data abstraction model comprising a plurality of third logical field definitions mapping to physical fields of a third database, wherein the first, second and third data abstraction models, and their respective logical field definitions, are distinct from one another, and wherein the at least one other device is configured to modify the abstract query to include one or more of the third logical field definitions from the third data abstraction model based on the respective concept codes; receive a second set of results for the abstract query from the at least one other device; and provide the first and second set of results to the requesting entity.
17. The system of claim 15 , wherein the network is a peer-to-peer network.