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 object
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 graphical user interface.

In MIND all local databases are encapsulated in a generic database
object with a well defined single interface. This approach hides the
differences between local databases from the rest of the system.  The
integration of export schemas is currently performed manually by using
an object definition language (ODL) which is based on OMG's interface
definition 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 are provided.