A generalized access path model and its application to a relational data base system
Carl Robert Carlson, Robert S. Kaplan · 1976
An Access Path Producing LanguagE (APPLE) has been developed which permits users to formulate completely non-procedural queries expressed solely in terms of attribute names. The responsibility for programming or specifying the access path by which a query is resolved has thus been shifted from the user to the system. Examples are presented which illustrate the procedures by which the system determines an access path. The problems to be found in this approach are also described, and techniques required to solve these problems are presented.