The MIND System: The Structure of the Semantic File

One of a series of Memoranda describing the design, implementation, and use of the MIND system, this study provides a detailed description of the way in which the main fact file of the MIND information-management system is organized. The format of each type of record is given in the form of a declaration in the PL/1 programming language. A method is described for organizing long lists of items so that any desired entry on the list can be retrieved with a minimum of accesses (usually one) to the disk. Also included is a set of computer procedures which can be incorporated into any program that has cause to refer to the file. These make it easy to store and retrieve information and to relieve the programmer of the necessity of bearing all the details of the file representation constantly in mind.