Using CIDOC CRM for dynamically querying ArSol, a relational database, from the semantic web.
Channel: Recording Archaeology
Date: 29/05/2015

Authors: Olivier Marlet, Stéphane Curet, Xavier Rodier, Béatrice Bouchou-Markhoff

Abstract: MASA Consortium (Mémoire des archéologues et des sites archéologiques http://masa.hypotheses.org/27), from the Très Grande Infrastructure de Recherche Huma-Num (http://www.huma-num.fr/) aims to provide to the french community of archaeologists several tools to improve their data interoperability. In this context, we propose to open the ArSol database to the semantic web, using the CIDOC-CRM ontology and a tool that implements Ontology-Based Data Access (OBDA) principles. The ArSol (Archives du Sol: Soil Archives) system has been used by the “Archéologie et Territoires” Laboratory (CNRS – Tours University) since 1990 for processing archaeological data. It can be used for all stratigraphic excavations and has the dual purpose of data management and research. It was constructed, with proprietary software, as an open system that is flexible and above all not conditioned by the integration of predefined thesauri. The ArSol client-server system is designed to integrate data from different sites. ArSol is designed both as a recording and data management research tool for use during excavation, and as an exploratory data analysis system for post-excavation work. Firstly, we designed a set of mappings from a selection of ArSol fields to the CIDOC CRM ontology. This manual alignment has been reported in CAA 2014. It allows us to transpose the ArSol data in an RDF format fully compatible with the CIDOC-CRM. We present in this article a new step, which is to implement the software architecture to query ArSol from a SPARQL endpoint. We chose to use Ontop, software developed at the University of Bozen-Bolzano that allows to query a relational database via an ontology, using SPARQL. In this way we do not need to move our data from our efficient database in order to benefit from the semantic web capabilities (semantic interoperability, RDF/OWL 2 QL inference, etc.). We avoid the extract-transform-load (ETL) process for exporting our data in an RDF store and for updating it when data change in ArSol. Via the SPARQL endpoint, users or applications can query ArSol using the CIDOC-CRM part that we selected to represent our ArSol data. We used the Ontop Protégé plugin to design the OBDA mappings that are necessary for the SPARQL-to-SQL rewritings. Our final goal is to devise an application that will offer a single interface to query several distributed and independent archaeological databases, with heterogeneous structures, using CIDOC-CRM to relate them to each other. Querying ArSol in SPARQL via the CIDOC CRM is an important step towards this goal.