19. The method of claim 1 , further comprising: mediating between the plurality of databases using a plurality of rules.
1. A method of servicing a multi-database query, the method comprising: receiving, by a computer, a query targeting a first ontology, wherein the first ontology comprises a user analytic ontology specified by a user; translating, by a computer, the query into one or more translated queries, each translated query targeting a respective ontology different from the first ontology; for each of the translated queries: issuing the translated query, by a computer, to a respective database organized according to the respective ontology of the translated query, and receiving, by a computer, a respective result set for the translated query, wherein the respective result set corresponds to the respective ontology of the translated query; for each of the respective result sets: translating, by a computer, the respective result set into a translated result set corresponding to the first ontology; aggregating, by a computer, the translated result sets into an aggregated result set corresponding to the first ontology; returning, by a computer, the aggregated results set corresponding to the first ontology; maintaining, by a computer, a plurality of ontologies and ontology alignments and mappings associated with said databases through versioning and governance of metadata of said databases; describing, by a computer, each database by a database schema; overlaying, by a computer, one or more database ontologies to each of said database schemas; mapping, by a computer, said database ontologies to a plurality of small domain ontologies; and combining, by a computer, said plurality of small domain ontologies to create system ontologies.