{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2024,8,7]],"date-time":"2024-08-07T07:32:52Z","timestamp":1723015972443},"publisher-location":"California","reference-count":0,"publisher":"International Joint Conferences on Artificial Intelligence Organization","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2020,7]]},"abstract":"<jats:p>Counting answers to a query is an operation supported by virtually all database management systems.\n\nIn this paper we focus on counting answers over a Knowledge Base (KB), which may be viewed as a database enriched with background knowledge about the domain under consideration.\n\nIn particular, we place our work in the context of Ontology-Mediated Query Answering\/Ontology-based Data Access (OMQA\/OBDA), where the language used for the ontology is a member of the DL-Lite family and the data is a (usually virtual) set of assertions.\n\nWe study the data complexity of query answering, for different members of the DL-Lite family that include number restrictions, and for variants of conjunctive queries with counting that differ with respect to their shape (connected, branching, rooted).\n\nWe improve upon existing results by providing PTIME and coNP lower bounds, and upper bounds in PTIME and LOGSPACE.\n\nFor the LOGSPACE case, we have devised a novel query rewriting technique into first-order logic with counting.<\/jats:p>","DOI":"10.24963\/ijcai.2020\/230","type":"proceedings-article","created":{"date-parts":[[2020,7,8]],"date-time":"2020-07-08T08:12:10Z","timestamp":1594195930000},"page":"1658-1666","source":"Crossref","is-referenced-by-count":0,"title":["Counting Query Answers over a DL-Lite Knowledge Base"],"prefix":"10.24963","author":[{"given":"Diego","family":"Calvanese","sequence":"first","affiliation":[{"name":"Free University of Bozen-Bolzano"},{"name":"Ume\u00e5 University"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Julien","family":"Corman","sequence":"additional","affiliation":[{"name":"Free University of Bozen-Bolzano"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Davide","family":"Lanti","sequence":"additional","affiliation":[{"name":"Free University of Bozen-Bolzano"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Simon","family":"Razniewski","sequence":"additional","affiliation":[{"name":"Max-Planck-Institut f\u00fcr Informatik, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"10584","event":{"number":"28","sponsor":["International Joint Conferences on Artificial Intelligence Organization (IJCAI)"],"acronym":"IJCAI-PRICAI-2020","name":"Twenty-Ninth International Joint Conference on Artificial Intelligence and Seventeenth Pacific Rim International Conference on Artificial Intelligence {IJCAI-PRICAI-20}","start":{"date-parts":[[2020,7,11]]},"theme":"Artificial Intelligence","location":"Yokohama, Japan","end":{"date-parts":[[2020,7,17]]}},"container-title":["Proceedings of the Twenty-Ninth International Joint Conference on Artificial Intelligence"],"original-title":[],"deposited":{"date-parts":[[2020,7,8]],"date-time":"2020-07-08T22:13:59Z","timestamp":1594246439000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.ijcai.org\/proceedings\/2020\/230"}},"subtitle":[],"proceedings-subject":"Artificial Intelligence Research Articles","short-title":[],"issued":{"date-parts":[[2020,7]]},"references-count":0,"URL":"https:\/\/doi.org\/10.24963\/ijcai.2020\/230","relation":{},"subject":[],"published":{"date-parts":[[2020,7]]}}}