Query processing for a knowledge-base using DOT algebra

Consideration is given to the query processing problem for a class of knowledge-based systems consisting of object names and labels. Each knowledge-based system in this class represents an IS-A relation and inheritance and its two important features are: no distinction between type and entity, and the capability to represent virtual objects. In order to discuss the query processing problem for such a system, a new algebra called DOT algebra is introduced. The authors show that a query concerning the IS-A relation is reduced to the problem to find the set of upper and/or lower bounds of a certain element of the DOT algebra. The answer to a query can be expressed by a regular expression, which is obtained by constructing an automaton from the query. They also show an implementation plan of the proposed knowledge-based system in a distributed system environment