Translation of relational queries into Description Logic for semantic cache query processing

Formulation of efficient algorithms to check implication and satisfibality for relational queries is an important research issue. Implication and satisfibality checking can be used to find query containment in semantic cache query processing and other similar applications. Description logic (DL) is a formalism used to model knowledge of a domain in the form of concepts and a rich set of associations between these concepts in the T-Boxes. Reasoning on these knowledge bases can be performed in order to find explicit relation as well as discover implicit relations. Sound and Complete subsumption algorithms exist for reasoning facts represented in Description Logic. The most common reasoning (which can be used for other sort of reasoning, too) is the determination of a subsumption relation between the logical expressions of T-boxes. In this paper, we propose an algorithm to translate relational queries in to description logic ALC(D), so that DL subsumption algorithms can be applied on these translated queries to find query containment. Working of the algorithm is demonstrated with the help of a case study. Conversion of relational query into DL will also help in optimization of cache size for the storage of semantics by eliminating redundant semantics in the cache. Hence, the sound and complete reasoning services of DL can be used for relational query containment.