Special issue of the Journal of Web Semantics on ontology-based data access

Diego Calvanese, Manolis Koubarakis, David Toman
2015 Journal of Web Semantics  
The competitiveness of many enterprises today relies on exploiting the wealth of information that is available in various distributed data sources or services. Thus, the problem of integrating data coming from many distributed and heterogeneous data sources has been a hot research topic for many years, and has received the attention of researchers in Databases, Knowledge Representation, and the Semantic Web. Furthermore, the recent utilization of "big data" in the private sector, government,
more » ... science has not only reinforced the importance of this topic but added the challenge of scaling to huge datasets. The ontology-based data access (OBDA) paradigm was formulated a few years ago to tackle the problem of data integration, and more generally that of accessing data sources with a complex structure. The OBDA approach is based on three components: the data layer, the conceptual model of the application that is used for expressing user requests, and the mapping between the two. The data layer might consist of a single, possibly federated, database, or by a collection of possibly distributed and heterogeneous data sources (this case is also known as ontology-based data integration). The conceptual model is represented by an ontology, typically formalized in an appropriate description logic, and user requests are expressed as queries over the ontology. The mapping between the conceptual model and the data sources is formalized by mapping assertions, which are based on an appropriate logical language, but which may also incorporate extra-logical features for data manipulation. The aim of an OBDA system is to answer user queries by transforming them into appropriate queries to the data layer, using the ontology and the mapping. This special issue covers recent advances in the OBDA approach. The call for papers resulted in 19 submissions that were carefully reviewed by at least three reviewers. Seven papers were accepted that offer a mix of OBDA theory and practice. The paper "Inconsistency-tolerant Query Answering in Ontologybased Data Access" by Domenico Lembo, Maurizio Lenzerini, Riccardo Rosati, Marco Ruzzi, and Domenico Fabio Savo addresses the problem of dealing with inconsistencies in OBDA. The general goal of the authors is both to study DL-based frameworks that are inconsistency-tolerant, and to devise techniques for answering unions of conjunctive queries under such inconsistency-tolerant semantics. The work of the authors builds on approaches to consistent query answering in databases, which are based on the idea of living with inconsistencies in the database, but trying to obtain only consistent information during query answering, by relying on the notion of database repair. The authors first adapt the * Corresponding editor.
doi:10.1016/j.websem.2015.06.001 fatcat:uqfd6zdr7vayvei2ylpuy7lzhy