23. The computer program product of claim 17 , wherein the storing comprises isolating semantic units of the generalized DAG in data value nodes, where the nodes of the generalized DAG are DAG nodes that reference the data value nodes, and at least two of the data value nodes are each referenced by more than one DAG node including a DAG node of a second DAG stored in the database.
23. The computer program product of claim 17 , wherein the storing comprises isolating semantic units of the generalized DAG in data value nodes, where the nodes of the generalized DAG are DAG nodes that reference the data value nodes, and at least two of the data value nodes are each referenced by more than one DAG node including a DAG node of a second DAG stored in the database. 24. The computer program product of claim 23 , wherein the storing comprises representing multiple facets of semantics of a domain as different DAGs, including the generalized DAG and the second DAG.