6. A method for responding to a model query to a data model, the method comprising: identifying a plurality of logical data models that each corresponds to a physical data model, wherein each given logical data model of the plurality of logical data models includes a logical data model index corresponding to the given logical data model that is configured to index a plurality of queries and at least partial query results corresponding to each of the plurality of queries, the indexed queries comprising queries issued to the given logical data model, and wherein each logical data model of the plurality of logical data models includes a different semantic mapping set that maps at least one logical data model entity to at least one entity of the physical data model; receiving a model query that identifies a particular logical data model of the plurality of logical data models; and in response to the received model query, accessing the logical data model index corresponding to the particular logical data model to determine whether results of the model query have been previously returned.
6. A method for responding to a model query to a data model, the method comprising: identifying a plurality of logical data models that each corresponds to a physical data model, wherein each given logical data model of the plurality of logical data models includes a logical data model index corresponding to the given logical data model that is configured to index a plurality of queries and at least partial query results corresponding to each of the plurality of queries, the indexed queries comprising queries issued to the given logical data model, and wherein each logical data model of the plurality of logical data models includes a different semantic mapping set that maps at least one logical data model entity to at least one entity of the physical data model; receiving a model query that identifies a particular logical data model of the plurality of logical data models; and in response to the received model query, accessing the logical data model index corresponding to the particular logical data model to determine whether results of the model query have been previously returned. 7. The method in accordance with claim 6 , wherein the system includes a cache configured to cache results of at least some model queries previously made to any of the plurality of logical data models.