OntRel: An optimized relational structure for storage of dynamic OWL-DL ontologies

Ontology is one of the most important components of semantic based information systems which provides context to the document. Ontology enables us to define relationship between different terminologies from diverse domains. To interpret this information and perform reasoning we require to store Ontologies in a way that retrieval becomes easy. Ontologies are defined using OWL (Web ontology language) which is based on XML. All the OWL documents are stored in the form of specialized XML files. With the increase in the semantic Websites number of ontologies describing different domains also grow and with their growth there comes a problem of storing these ontologies. With the passage of time it has been established that RDBMS (relational database management systems) is the most efficient and reliable data structure in terms of storage and retrieval. To store OWL documents in RDBMS multiple techniques have been proposed, but they still lack the advantages of RDBMS. All the databases in RDBMS are closed in nature, but OWL documents are inherently dynamic and semi-structured. So, there is a need to preserve the dynamic OWL documents in the relational structure in such an way that no data or relationship is lost and advantages of RDBMS are also gained. This paper briefly presents the survey of existing ontologies with comparative analysis on the basis of load time and query performance. Secondly, this paper makes a contribution by proposing a rule based approach to improve the downside of earlier techniques.