Database Access Requirements of Knowledge-Based Systems

Knowledge bases constitute the core of those Artificial Intelligenceprograms which have come to be known as Expert Systems. Anexamination of the most dominant knowledge representation schemes usedin these systems reveals that a knowledge base can, and possiblyshould, be described at several levels using different schemes,including those traditionally used in operational databases. Thischapter provides evidence that solutions to the organization andaccess problem for very large knowledge bases require the employmentof appropriate database management methods, at least for the lowestlevel of description -- the facts or data. We identify the databaseaccess requirements of knowledge-based or expert systems and thenpresent four general architectural strategies for the design of expertsystems that interact with databases, together with specificrecommendations for their suitability in particular situations. Animplementation of the most advanced and ambitious of these strategiesis then discussed in some detail