D. Tsichritzis and A. Kluge (eds.): "The ANSI/X3/SPARC DBMS Framework: Report of the Study Group on Database Management Systems", Information Systems 3, APIPS Press, 1978  Home/Search   Document Not in Database   Summary   Related Articles   Check

.... execution autonomy, which refer to the ability of a component database to execute local operations An adequate database architecture has to be aware of these three dimensions (distribution, heterogeneity and autonomy) of a federated database system. The ANSI SPARC three level architecture [TK78] therefore, is inadequate and has to be extended to support these dimensions. SL90] provides a five level architecture for federated systems. Based on the local conceptual schemas of each component database, a so called component schema must be developed. A component schema is derived by ....

D. Tsichritzis and A. Kluge (eds.): "The ANSI/X3/SPARC DBMS Framework: Report of the Study Group on Database Management Systems", Information Systems 3, APIPS Press, 1978

....result set does not consist of objects but of (maybe complex) values. We distinguish between the conceptual schema, which described the database from a global, uniform point of view and external schemes, which have a perspective on the database that is specific to a group of users or applications [10]. An external schema is based on a conceptual schema and explicitly states which parts of the global schema are needed. External schemes serve as a logical buffer to minimize impacts of schema changes, be it in the conceptual or external level [5] 3. DERIVATION OF EXTERNAL TYPES 3.1 Elements of ....

D. Tsichritzis, A. Klug (eds.): "The ANSI/X3/SPARC DBMS Framework: Report of the Study Group on Database Management Systems." Information Systems 3 (1978).

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