Rewriting Guarded Existential Rules into Small Datalog Programs

Authors Shqiponja Ahmetaj, Magdalena Ortiz, Mantas Simkus



PDF
Thumbnail PDF

File

LIPIcs.ICDT.2018.4.pdf
  • Filesize: 0.52 MB
  • 24 pages

Document Identifiers

Author Details

Shqiponja Ahmetaj
Magdalena Ortiz
Mantas Simkus

Cite AsGet BibTex

Shqiponja Ahmetaj, Magdalena Ortiz, and Mantas Simkus. Rewriting Guarded Existential Rules into Small Datalog Programs. In 21st International Conference on Database Theory (ICDT 2018). Leibniz International Proceedings in Informatics (LIPIcs), Volume 98, pp. 4:1-4:24, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2018)
https://doi.org/10.4230/LIPIcs.ICDT.2018.4

Abstract

The goal of this paper is to understand the relative expressiveness of the query language in which queries are specified by a set of guarded (disjunctive) tuple-generating dependencies (TGDs) and an output (or 'answer') predicate. Our main result is to show that every such query can be translated into a polynomially-sized (disjunctive) Datalog program if the maximal number of variables in the (disjunctive) TGDs is bounded by a constant. To overcome the challenge that Datalog has no direct means to express the existential quantification present in TGDs, we define a two-player game that characterizes the satisfaction of the dependencies, and design a Datalog query that can decide the existence of a winning strategy for the game. For guarded disjunctive TGDs, we can obtain Datalog rules with disjunction in the heads. However, the use of disjunction is limited, and the resulting rules fall into a fragment that can be evaluated in deterministic single exponential time. We proceed quite differently for the case when the TGDs are not disjunctive and we show that we can obtain a plain Datalog query. Notably, unlike previous translations for related fragments, our translation requires only polynomial time if the maximal number of variables in the (disjunctive) TGDs is bounded by a constant.
Keywords
  • Existential rules
  • Expressiveness
  • Descriptive Complexity
  • Query Rewriting

Metrics

  • Access Statistics
  • Total Accesses (updated on a weekly basis)
    0
    PDF Downloads

References

  1. Shqiponja Ahmetaj, Magdalena Ortiz, and Mantas Simkus. Polynomial datalog rewritings for expressive description logics with closed predicates. In Subbarao Kambhampati, editor, Proceedings of the Twenty-Fifth International Joint Conference on Artificial Intelligence, IJCAI 2016, New York, NY, USA, 9-15 July 2016, pages 878-885. IJCAI/AAAI Press, 2016. URL: http://www.ijcai.org/Abstract/16/129.
  2. Hajnal Andréka, István Németi, and Johan van Benthem. Modal languages and bounded fragments of predicate logic. J. Philosophical Logic, 27(3):217-274, 1998. URL: http://dx.doi.org/10.1023/A:1004275029985.
  3. Vince Bárány, Michael Benedikt, and Balder ten Cate. Rewriting guarded negation queries. In Proc. of MFCS' 13, pages 98-110. ACM, 2013. Google Scholar
  4. Vince Bárány, Georg Gottlob, and Martin Otto. Querying the guarded fragment. In Proceedings of the 25th Annual IEEE Symposium on Logic in Computer Science, LICS 2010, 11-14 July 2010, Edinburgh, United Kingdom, pages 1-10. IEEE Computer Society, 2010. URL: http://dx.doi.org/10.1109/LICS.2010.26.
  5. Vince Bárány, Balder ten Cate, and Martin Otto. Queries with guarded negation. PVLDB, 5(11):1328-1339, 2012. URL: http://vldb.org/pvldb/vol5/p1328_vincebarany_vldb2012.pdf.
  6. Catriel Beeri and Moshe Y. Vardi. A proof procedure for data dependencies. J. ACM, 31(4):718-741, 1984. URL: http://dx.doi.org/10.1145/1634.1636.
  7. Meghyn Bienvenu, Balder ten Cate, Carsten Lutz, and Frank Wolter. Ontology-based data access: A study through disjunctive datalog, csp, and MMSNP. ACM Trans. Database Syst., 39(4):33:1-33:44, 2014. URL: http://dx.doi.org/10.1145/2661643.
  8. Pierre Bourhis, Marco Manna, Michael Morak, and Andreas Pieris. Guarded-based disjunctive tuple-generating dependencies. ACM Trans. Database Syst., 41(4):27:1-27:45, 2016. URL: http://dx.doi.org/10.1145/2976736.
  9. Andrea Calì, Georg Gottlob, and Michael Kifer. Taming the infinite chase: Query answering under expressive relational constraints. J. Artif. Intell. Res., 48:115-174, 2013. URL: http://dx.doi.org/10.1613/jair.3873.
  10. Diego Calvanese, Giuseppe De Giacomo, Domenico Lembo, Maurizio Lenzerini, and Riccardo Rosati. Tractable reasoning and efficient query answering in description logics: The DL-Lite family. J. Autom. Reasoning, 39(3):385-429, 2007. URL: http://dx.doi.org/10.1007/s10817-007-9078-x.
  11. Alin Deutsch and Val Tannen. Reformulation of XML queries and constraints. In Diego Calvanese, Maurizio Lenzerini, and Rajeev Motwani, editors, Database Theory - ICDT 2003, 9th International Conference, Siena, Italy, January 8-10, 2003, Proceedings, volume 2572 of Lecture Notes in Computer Science, pages 225-241. Springer, 2003. URL: http://dx.doi.org/10.1007/3-540-36285-1_15.
  12. Thomas Eiter, Georg Gottlob, and Heikki Mannila. Disjunctive datalog. ACM Trans. Database Syst., 22(3):364-418, 1997. URL: http://dx.doi.org/10.1145/261124.261126.
  13. Thomas Eiter, Magdalena Ortiz, Mantas Simkus, Trung-Kien Tran, and Guohui Xiao. Query rewriting for horn-shiq plus rules. In Jörg Hoffmann and Bart Selman, editors, Proceedings of the Twenty-Sixth AAAI Conference on Artificial Intelligence, July 22-26, 2012, Toronto, Ontario, Canada. Press, 2012. URL: http://www.aaai.org/ocs/index.php/AAAI/AAAI12/paper/view/4931.
  14. Georg Gottlob, Stanislav Kikot, Roman Kontchakov, Vladimir V. Podolskii, Thomas Schwentick, and Michael Zakharyaschev. The price of query rewriting in ontology-based data access. Artif. Intell., 213:42-59, 2014. URL: http://dx.doi.org/10.1016/j.artint.2014.04.004.
  15. Georg Gottlob, Marco Manna, Michael Morak, and Andreas Pieris. On the complexity of ontological reasoning under disjunctive existential rules. In Branislav Rovan, Vladimiro Sassone, and Peter Widmayer, editors, Mathematical Foundations of Computer Science 2012 - 37th International Symposium, MFCS 2012, Bratislava, Slovakia, August 27-31, 2012. Proceedings, volume 7464 of Lecture Notes in Computer Science, pages 1-18. Springer, 2012. URL: http://dx.doi.org/10.1007/978-3-642-32589-2_1.
  16. Georg Gottlob, Marco Manna, and Andreas Pieris. Polynomial combined rewritings for existential rules. In Chitta Baral, Giuseppe De Giacomo, and Thomas Eiter, editors, Principles of Knowledge Representation and Reasoning: Proceedings of the Fourteenth International Conference, KR 2014, Vienna, Austria, July 20-24, 2014. AAAI Press, 2014. URL: http://www.aaai.org/ocs/index.php/KR/KR14/paper/view/7973.
  17. Georg Gottlob, Marco Manna, and Andreas Pieris. Polynomial rewritings for linear existential rules. In Qiang Yang and Michael Wooldridge, editors, Proceedings of the Twenty-Fourth International Joint Conference on Artificial Intelligence, IJCAI 2015, Buenos Aires, Argentina, July 25-31, 2015, pages 2992-2998. AAAI Press, 2015. URL: http://ijcai.org/Abstract/15/423.
  18. Georg Gottlob, Sebastian Rudolph, and Mantas Simkus. Expressiveness of guarded existential rule languages. In Richard Hull and Martin Grohe, editors, Proceedings of the 33rd ACM SIGMOD-SIGACT-SIGART Symposium on Principles of Database Systems, PODS'14, Snowbird, UT, USA, June 22-27, 2014, pages 27-38. ACM, 2014. URL: http://dx.doi.org/10.1145/2594538.2594556.
  19. Georg Gottlob and Thomas Schwentick. Rewriting ontological queries into small nonrecursive datalog programs. In Gerhard Brewka, Thomas Eiter, and Sheila A. McIlraith, editors, Principles of Knowledge Representation and Reasoning: Proceedings of the Thirteenth International Conference, KR 2012, Rome, Italy, June 10-14, 2012. AAAI Press, 2012. URL: http://www.aaai.org/ocs/index.php/KR/KR12/paper/view/4510.
  20. Erich Grädel. On the restraining power of guards. J. Symb. Log., 64(4):1719-1742, 1999. Google Scholar
  21. Ullrich Hustadt, Boris Motik, and Ulrike Sattler. Reasoning in description logics by a reduction to disjunctive datalog. J. Autom. Reasoning, 39(3):351-384, 2007. URL: http://dx.doi.org/10.1007/s10817-007-9080-3.
  22. Mark Kaminski, Yavor Nenov, and Bernardo Cuenca Grau. Datalog rewritability of disjunctive datalog programs and its applications to ontology reasoning. In Carla E. Brodley and Peter Stone, editors, Proceedings of the Twenty-Eighth AAAI Conference on Artificial Intelligence, July 27 -31, 2014, Québec City, Québec, Canada., pages 1077-1083. AAAI Press, 2014. URL: http://www.aaai.org/ocs/index.php/AAAI/AAAI14/paper/view/8201.
  23. Roman Kontchakov, Carsten Lutz, David Toman, Frank Wolter, and Michael Zakharyaschev. The combined approach to ontology-based data access. In Toby Walsh, editor, IJCAI 2011, Proceedings of the 22nd International Joint Conference on Artificial Intelligence, Barcelona, Catalonia, Spain, July 16-22, 2011, pages 2656-2661. IJCAI/AAAI, 2011. URL: http://dx.doi.org/10.5591/978-1-57735-516-8/IJCAI11-442.
  24. Carsten Lutz. Inverse roles make conjunctive queries hard. In Diego Calvanese, Enrico Franconi, Volker Haarslev, Domenico Lembo, Boris Motik, Anni-Yasmin Turhan, and Sergio Tessaris, editors, Proceedings of the 2007 International Workshop on Description Logics (DL2007), Brixen-Bressanone, near Bozen-Bolzano, Italy, 8-10 June, 2007, volume 250 of CEUR Workshop Proceedings. CEUR-WS.org, 2007. URL: http://ceur-ws.org/Vol-250/paper_3.pdf.
  25. Carsten Lutz, Inanç Seylan, and Frank Wolter. Ontology-based data access with closed predicates is inherently intractable(sometimes). In Francesca Rossi, editor, IJCAI 2013, Proceedings of the 23rd International Joint Conference on Artificial Intelligence, Beijing, China, August 3-9, 2013, pages 1024-1030. IJCAI/AAAI, 2013. URL: http://www.aaai.org/ocs/index.php/IJCAI/IJCAI13/paper/view/6870.
  26. Carsten Lutz, Inanç Seylan, and Frank Wolter. Ontology-based data access with closed predicates is inherently intractable(sometimes). In Francesca Rossi, editor, IJCAI 2013, Proceedings of the 23rd International Joint Conference on Artificial Intelligence, Beijing, China, August 3-9, 2013, pages 1024-1030. IJCAI/AAAI, 2013. URL: http://www.aaai.org/ocs/index.php/IJCAI/IJCAI13/paper/view/6870.
  27. Magdalena Ortiz, Sebastian Rudolph, and Mantas Simkus. Worst-case optimal reasoning for the horn-dl fragments of OWL 1 and 2. In Fangzhen Lin, Ulrike Sattler, and Miroslaw Truszczynski, editors, Principles of Knowledge Representation and Reasoning: Proceedings of the Twelfth International Conference, KR 2010, Toronto, Ontario, Canada, May 9-13, 2010. AAAI Press, 2010. URL: http://aaai.org/ocs/index.php/KR/KR2010/paper/view/1296.
  28. Héctor Pérez-Urbina, Boris Motik, and Ian Horrocks. Tractable query answering and rewriting under description logic constraints. J. Applied Logic, 8(2):186-209, 2010. URL: http://dx.doi.org/10.1016/j.jal.2009.09.004.
  29. Despoina Trivela, Giorgos Stoilos, Alexandros Chortaras, and Giorgos B. Stamou. Optimising resolution-based rewriting algorithms for OWL ontologies. J. Web Sem., 33:30-49, 2015. URL: http://dx.doi.org/10.1016/j.websem.2015.02.001.
Questions / Remarks / Feedback
X

Feedback for Dagstuhl Publishing


Thanks for your feedback!

Feedback submitted

Could not send message

Please try again later or send an E-mail