Abstract Retrieval-By-Unification Operation on a Relational Knowledge Base

This paper describes a method for retrieval-by-unification (RBU) operations, especially unification-join, on a relational knowledge base. The relational knowledge base is a conceptual model for a knowledge base. In this model knowledge is represented by term relations. Terms in the term relations are retrieved with operation called RBUs (i.e., unification-join and unification-restriction). To perform unification-join in the simplest manner, all possible pairs of tuples in term relations should be checked to see if each pair of terms in the tuples is unifiable or not. This would result in an extremely heavy processing load. We propose a method which involves ordering terms and, as result, omitting some pairs from this processing. The paper also de-scribes a method for implementing the unificaiion en-gine (UE), that is, hardware dedicated to the RBU op-erations