Document Server@UHasselt >
Research >
Research publications >

Please use this identifier to cite or link to this item: http://hdl.handle.net/1942/21878

Title: On the satisfiability problem for SPARQL patterns
Authors: Zhang, Xiaowang
Van den Bussche, Jan
Picalausa, François
Issue Date: 2016
Abstract: The satisfiability problem for SPARQL 1.0 patterns is undecidable in general, since the relational algebra can be emulated using such patterns. The goal of this paper is to delineate the boundary of decidability of satisfiability in terms of the constraints allowed in filter conditions. The classes of constraints considered are bound-constraints, negated bound- constraints, equalities, nonequalities, constant-equalities, and constant-nonequalities. The main result of the paper can be summarized by saying that, as soon as inconsistent filter conditions can be formed, satisfiability is undecidable. The key insight in each case is to find a way to emulate the set difference operation. Undecidability can then be obtained from a known undecidability result for the algebra of binary relations with union, composition, and set difference. When no inconsistent filter conditions can be formed, satisfiability is decidable by syntactic checks on bound variables and on the use of literals. Although the problem is shown to be NP-complete, it is experimentally shown that the checks can be implemented efficiently in practice. The paper also points out that satisfiability for the so-called ‘well-designed’ patterns can be decided by a check on bound variables and a check for inconsistent filter conditions.
Notes: Zhang, XW (reprint author), Tianjin Univ, Sch Comp Sci & Technol, Tianjin Key Lab Cognit Comp & Applicat, Tianjin, Peoples R China. xiaowangzhang@tju.edu.cn; jan.vandenbussche@uhasselt.be; fpicalausa@gmail.com
URI: http://hdl.handle.net/1942/21878
Link to publication: http://www.jair.org/media/5028/live-5028-9408-jair.pdf
DOI: 10.1613/jair.5028
ISI #: 000380245700001
ISSN: 1076-9757
Category: A1
Type: Journal Contribution
Validation: ecoom, 2017
Appears in Collections: Research publications

Files in This Item:

Description SizeFormat
published version354.39 kBAdobe PDF

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.