{"type":"ScholarlyArticle","title":"Intensional and Extensional Views in DL-Lite Ontologies","authors":[{"name":"Marco Console","slug":"marco-console","given":"Marco","family":"Console","affiliation":""},{"name":"Giuseppe De Giacomo","slug":"giuseppe-de-giacomo","given":"Giuseppe","family":"De Giacomo","affiliation":""},{"name":"Maurizio Lenzerini","slug":"maurizio-lenzerini","given":"Maurizio","family":"Lenzerini","affiliation":""},{"name":"Manuel Namici","slug":"manuel-namici","given":"Manuel","family":"Namici","affiliation":""}],"abstract":"The use of virtual collections of data is often essential in several\r\ndata and knowledge management tasks. In the literature, the standard\r\nway to define virtual data collections is via views, i.e., virtual\r\nrelations defined using queries.  In data and knowledge bases, the\r\nnotion of views is a staple of data access, data integration and\r\nexchange, query optimization, and data privacy.  In this work, we\r\nstudy views in Ontology-Based Data Access (OBDA) systems.\r\nOBDA is a powerful paradigm for accessing data through an\r\nontology, i.e., a conceptual specification of the domain of interest\r\nwritten using logical axioms. Intuitively, users of an OBDA system\r\ninteract with the data only through the ontology's conceptual lens. We\r\npresent a novel framework to express natural and sophisticated forms\r\nof views in OBDA systems and introduce fundamental reasoning tasks for\r\nthese views. We study the computational complexity of these tasks and\r\npresent classes of views for which these tasks are tractable or at\r\nleast decidable.","doi":"10.24963/ijcai.2021/251","url":"https://ijcai.org/proceedings/2021/251","pdf":"https://ijcai.org/proceedings/2021/0251.pdf","markdown":"https://ijcai.org/proceedings/2021/251.md","bibtex":"https://ijcai.org/proceedings/2021/bibtex/251","volume":{"slug":"2021","title":"Proceedings of the Thirtieth International Joint Conference on Artificial Intelligence","short_title":"IJCAI 2021","url":"https://ijcai.org/proceedings/2021/","year":2021,"location":"Montreal","dates":"19-27 August 2021","editors":"Prof. Zhi-Hua Zhou","isbn":"978-0-9992411-9-6","publisher":"International Joint Conferences on Artificial Intelligence Organization","doi_prefix":"10.24963/ijcai.2021"},"section":"Knowledge Representation and Reasoning","track":"Main Track","number":251,"pages":{"first":1822,"last":1828},"keywords":["Knowledge Representation and Reasoning: Description Logics and Ontologies","Knowledge Representation and Reasoning: Knowledge Representation Languages","Knowledge Representation and Reasoning: Reasoning about Knowledge and Belief"],"videos":[],"references":[],"license_note":"Copyright International Joint Conferences on Artificial Intelligence."}