No abstract

METU INteroperable Database System (MIND) is a multidatabase system that aims at achieving interoperability among heterogeneous, federated DBMSs. MIND architecture is based on OMG distributed o b j e ct management model. It is implemented on top of a CORBA compliant ORB, namely, ObjectBroker. MIND provides users a single ODMG-93 compliant common data model, and a single global query language based on SQL. This makes it possible to incorporate both relational and object oriented databases into the system. Currently Oracle7, Sybase and METU OODBMS (MOOD) have been incorporated into MIND. The main components of MIND are a global query processor, a global transaction manager, a schema integrator, interfaces to supported database systems and a user graphical interface.In MIND all local databases are encapsulated in a generic database object with a well de ned single interface. This approach hides the di erences between local databases from the rest of the system. The integration of export schemas is currently performed manually by using an object de nition language (ODL) which is based on OMG's interface de nition language. The DBA builds the integrated schema as a view over export schemas. The functionalities of ODL allow selection and restructuring of schema elements from existing local schemas.MIND global query optimizer aims at maximizing the parallel execution of the intersite joins of the global subqueries. Through MIND global transaction manager, the serializable execution of the global transactions a r e p r ovided.

No abstract