Access Control and Retrieval Optimization Functions of the Supervisor for an Extended Data Management Facility

The purpose of the Supervisor in an Extended Data Management Facility (EDMF) is to direct the Facility's handling of a user's request for service. The Supervisor fulfills its task through the use of five main functions: Access Control, Retrieval Initialization, File Searching, Record Validating and Record Formatting. The major and most important component of the Retrieval Initialization phase is the Retrieval Optimization subfunction. This report is concerned mainly with the design and implementation of the Access Control and Retrieval Optimization functions. Macro instructions are the mechanism through which a user's program can call upon the ECMF. The Authority Item check is the EDMF's security control over file access while the Prime Keyword Search is the method used to optimize the retrieval strategy. The Authority Item check and the Prime Keyword Search are two of the major concepts of the Extended Data Management Facility.