A multidatabase system implementation on CORBA

METU Interoperable DBMS (MIND) is a multidatabase system based on OMG´s distributed object management architecture. It is implemented on top of a CORBA compliant ORB, namely, DEC´s ObjectBroker. In MIND, all local databases are encapsulated in a generic database object. The interface of the generic database object is defined in CORBA IDL and multiple implementations of this interface, one for each component DBMS, namely Sybase, Adabas D and MOOD are provided. MIND provides its users with a common data model and a single global query language based on SQL. The main components of MIND are a global query manager, a global transaction manager, a schema integrator, interfaces to supported database systems and a graphical user interface. The integration of export schemas is currently performed by using an object definition language (ODL) which is based on OMG´s interface definition language. MIND global query optimizer aims at maximizing the parallel execution of the intersite operations of the global subqueries. Through the MIND global transaction manager, the serializable execution of the global transactions (both nested and flat) is provided