6. A method for schema integration comprising: recasting a first source schema into a first graph of concepts with HasA relationships; recasting a second source schema into a second graph of concepts with HasA relationships; identifying matching concepts in the first graph and the second graph based on correspondences between attributes of the concepts; enumerating the first graph of concepts and the second graph of concepts to output a plurality of integrated schemas that consider choices of concepts that merge and concepts that do not merge; applying enumeration constraints to determine how the concepts merge; and systematically determining alternative integrated schemas and associated mappings, based on identifying possible choices of matching concepts to merge to produce an integrated schema from the plurality of integrated schemas.
7. The method as claimed in claim 6 , wherein each alternative integrated schema is determined on demand in combination with user interaction.