Model Driven Enterprise Information Management in Carnot

This paper describes MCC's Distributed Semantic Query Manager, DSQM, which executes queries and/ or updates against integrated information resources in the context of enterprise integration. The main ideas are (1) using articulation axioms and value mappings to dynamically expand a query into subqueries that access all semantically equivalent and relevant information resources; (2) using a declarative resource constraint base to generate relaxed transactions for the modification of information; (3) optimizing queries that may involve semantic equivalence and relaxed temporal constraints; and (4) generating a distributed query plan that can be concurrently executed in the Caroot distributed environment. With the curoent implementation and experiments, DSQM has demonstrated a wide range of features. These include efficient representation for information integration (requires only 0(n) linkages); clear declarative boundaries between models and applications for flexible improvements and modifications; support for heterogeneous and distributed applications, with the option of leaving existing applications intact; expressiveness for integrating heterogeneous schemes and different value formats with the option of “value tagging;” and optimization of queries that are semantically distributed in a large number of heterogeneous platforms. The control structure of DSQM has been implemented as MCC Extensible Services Switch actors, which supply an extensible, object-oriented, concurrent environment for dynamic, reconfigurable execution of services. Individual functions of DSQM have been implemented in C and C++.