Embedding XPATH Queries into SPARQL Queries

While XPath is an established query language developed by the W3C for XML, SPARQL is a new query language developed by the W3C for RDF data. Comparisons between the data models of XML and RDF and between the query languages XPath and SPARQL are missing. Since XML and XPath are earlier recommendations of the W3C than RDF and SPARQL, currently more XML data and XPath queries are used in applications. However, recently available SPARQL query evaluators do not deal with XML data and XPath queries. We have developed a prototype for translating XML data into RDF data and embedding XPath queries into SPARQL queries for the following two reasons: 1) We want to compare the XPath and XQuery data model with the RDF data model and the XPath query language with the SPARQL query language in order to show similarities and differences. 2) We want to enable SPARQL query evaluators to deal with XML data and XPath queries in order to support XPath processing and SPARQL processing in parallel. We have developed a prototype for the source-to-source translations from XML data into RDF data and from XPath queries into SPARQL queries. We have run experiments to measure the execution times of the translations, of XPath queries and of their translated SPARQL queries.