Multiple database integration in CALIDA: design and implementation

The authors discuss the issues of integration of multiple heterogeneous databases and describe a system called CALIDA, developed to access corporate data from relational databases, variable-record-type files, and flat files. The database integration model used in CALIDA contains three levels: the conceptual or language level, the logical or schema level, and physical or data level. The conceptual framework for database integration proposed in CALIDA covers a variety of heterogeneous databases. CALIDA is implemented in Interlisp-D on a Xerox 1186 workstation and accesses remote IBM mainframe resident databases via a wide-area network.<
>