A Framework for Incremental Maintenance of RDF Views of Relational Data Vˆ ania M. P. Vidal 1 , Marco A. Casanova 2 , Jos´ e M. Monteiro 1 , Narciso Arruda 1 , Diego S´ a 1 , and Val´ eria M. Pequeno 3 1 Federal University of Cear´ a, Fortaleza, CE, Brazil {vvidal, jmmfilho, narciso, diego}@lia.ufc.br 2 Pontifical Catholic University of Rio de Janeiro, RJ, Brazil casanova@inf.puc-rio.br 3 DMIR, INESC-ID Porto Salvo, Portugal vmp@inesc-id.pt Abstract. A general and flexible way to publish relational data in RDF format is to create RDF views of the underlying relational data. In this paper, we demonstrate a framework, based on rules, for the incremen- tal maintenance of RDF views defined on top of relational data. We also demonstrate a tool that automatically generates, based on the map- ping between the relational schema and a target ontology, the RDF view exported from the relational data source and all rules required for the incremental maintenance of the RDF view. Keywords: RDF View Maintenance, RDB-to-RDF, Linked Data 1 Introduction The Linked Data initiative [1] promotes the publication of previously isolated databases as interlinked RDF triple sets, thereby creating a global scale datas- pace, known as the Web of Data. However, the full potential of linked data depends on how easy it is to publish data stored in relational databases (RDBs) in RDF format. This process is often called RDB-to-RDF. A general way to publish relational data in RDF format is to create RDF views of the relational data. The contents of views can be materialized to improve query performance and data availability. However, to be useful, a materialized view must be continuously maintained to reflect dynamic source updates. In this demo, we show a framework, based on rules, for the incremental maintenance of external RDF views defined on top of relational data. Figure 1 depicts the main components of the framework. Briefly, the administrator of a relational data-base, using Rubya (Rules by assertion), should create RDF views and define a set of rules using Rubya - Figure 1(a). These rules are responsible for: (i) computing the view maintenance statements necessary to maintain a materialized view V with respect to base updates; and (ii) sending the view maintenance statements to the view controller of V - Figure 1(b). The rules can be implemented using triggers. Hence, no middleware system is required. The