An ontological approach to describe the SQL: 2003 object-relational features

The SQL (Structured Query Language) is currently available in most database management systems and is the focus of an intense standardization process resulting in the latest version of the SQL:2003 standard. Standards are fundamental, but often they are difficult to use, due to their lack of understandability and the occurrence of inconsistencies. An ontology is useful for clarifying the elements of a standard, along with their interrelationships, as well as for detecting inconsistencies. In this paper we propose an ontology for the object-relational features of the new SQL:2003 standard, formalized with UML 2.0 class diagrams and OCL well-formedness rules. The ontology is instantiated with an example in which most of the new objectrelational features of the SQL:2003 standard are presented. D 2005 Elsevier B.V. All rights reserved.