The relational database layout to store ontology knowledge base

The Semantic Web has been recognized as the next generation web which aims at the automation, integration and reuse of data across different web applications. To realize the Semantic Web, the W3C has adopted standards and tools such as the Resource Description Framework (RDF) and Web Ontology Language (OWL). With the development of the Semantic Web, OWL ontology became a W3C recommended mechanism and state-of-the-art technology toward the ideal Semantic Web. Most semantic web applications developed for such an environment require the management of large amounts of semantic data which are stored in semantic models. This requirement has motivated the design of specialized repositories in order to store and manipulate semantic models. However, semantic repositories still have problems related to hierarchical relations in that OWL data cannot be directly represented by a relation table i.e. `a single table´. In this paper, we propose a new relational database layout to store an OWL knowledge base by considering the hierarchical relations.