This report surveys the state of semantic web storage for RDF / triple data using existing free software tools. It takes a practical approach by targeting the work to the needs of developers, answering frequently asked questions related to this subject. The report first reviews previous work in surveying semantic web data, schema and triple stores, then gives an overview of the major systems with their feature set and maturity and then uses that information to provide a set of FAQs with answers related to storing semantic web data.
The Resource Description Framework (RDF) is a W3C standard for describing Web resources, such as the title, author, modification date, content, and copyright information of a Web page. What is RDF? RDF stands for Resource Description Framework RDF is
"In Semantic Web languages, such as RDF and OWL, a property is a binary relation: it is used to link two individuals or an individual and a value. However, in some cases, the natural and convenient way to represent certain concepts is to use relations to link an individual to more than just one individual or value. These relations are called n-ary relations. For example, we may want to represent properties of a relation, such as our certainty about it, severity or strength of a relation, relevance of a relation, and so on. Another example is representing relations among multiple individuals, such as a buyer, a seller, and an object that was bought when describing a purchase of a book. This document presents ontology patterns for representing n-ary relations in RDF and OWL and discusses what users must consider when choosing these patterns."