In 1972, the American National Standards Institute’s Standards Planning and Requirements Committee (SPARC) established a Study Group on Database Architectures. In February of 1975, they published an interim report which explained in detail the gross architecture they had developed for information systems.
At the heart of the report was the “three-schema approach” to database management. The three were:
· Conceptual Schema – This “embodies the ‘real world’ view of the enterprise being modeled in the data base. It represents the current ‘best model’ or ‘way of doing business’ for the enterprise.”
· External Schema – “The various users of the database management system operate on sub-sets of ...