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Answering Conjunctive Regular Path Queries over Guarded Existential Rules

Jean-François Baget, Meghyn Bienvenu, Marie-Laure Mugnier, Michael Thomazo
2017 Proceedings of the Twenty-Sixth International Joint Conference on Artificial Intelligence  
In this paper, we investigate the complexity of answering two-way conjunctive regular path queries (CRPQs) over knowledge bases whose ontology is given by a set of guarded existential rules.  ...  For guarded rules, we provide a non-trivial reduction to the linear case, which allows us to show that the complexity of CRPQ answering is the same as for plain conjunctive queries, namely, 2EXPTIME-complete  ...  A conjunctive two-way regular path query (CRPQ 1 ) has the form q(x) = ∃y.B and is defined as a CQ except that B is a conjunction of standard and path atoms.  ... 
doi:10.24963/ijcai.2017/110 dblp:conf/ijcai/BagetBMT17 fatcat:cm3joww2bzgwvhrxadirwh3xna

The Two Views on Ontological Query Answering

Sebastian Rudolph
2014 Alberto Mendelzon Workshop on Foundations of Data Management  
We give an overview of the two views as well as ensuing conditions for decidability, focusing on existential rules as ontological formalism that has lately gained a lot of renewed interest from both the  ...  We attempt a structured view at the ontological query answering problem by distinguishing between two antagonistic perspectives: The knowledge representation perspective considers the ontology as a part  ...  2-way regular path queries (cf.  ... 
dblp:conf/amw/Rudolph14 fatcat:4s3gtj52cfe6vlpj3evy4usnoe

Navigational Queries Based on Frontier-Guarded Datalog: Preliminary Results

Meghyn Bienvenu, Magdalena Ortiz, Mantas Simkus
2015 Alberto Mendelzon Workshop on Foundations of Data Management  
Our query language strictly extends conjunctive two-way regular path queries (C2RPQs) and captures some of the key features advocated in recent works aimed at extending C2RPQs.  ...  In this paper, we introduce a navigational query language that extends binary frontier-guarded Datalog by allowing regular expressions in rule bodies and a limited use of higher-arity intensional predicates  ...  Conjunctive two-way regular path queries (C2RPQs) and their unions (UC2RPQs), which simultaneously extend both the well-known conjunctive queries (CQs) and two-way regular path queries (RPQs), have established  ... 
dblp:conf/amw/BienvenuOS15 fatcat:q4jv3d6msjbgxnp3oxlpbyo6z4

Ontology-Mediated Query Answering for Key-Value Stores

Meghyn Bienvenu, Pierre Bourhis, Marie-Laure Mugnier, Sophie Tison, Federico Ulliana
2017 Proceedings of the Twenty-Sixth International Joint Conference on Artificial Intelligence  
We propose a novel rule-based ontology language for JSON records and investigate its computational properties.  ...  After providing a natural translation into first-order logic, we identify relationships to existing ontology languages, which yield decidability of query answering but only rough complexity bounds.  ...  answering, namely frontier-guarded existential rules, in which an atom from the rule body (called a guard) contains all the frontier variables, which are the variables shared by the body and the head  ... 
doi:10.24963/ijcai.2017/117 dblp:conf/ijcai/BienvenuBMTU17 fatcat:4dxsf4knbbgfvbr75kl35bnnwq

Provenance Circuits for Trees and Treelike Instances [chapter]

Antoine Amarilli, Pierre Bourhis, Pierre Senellart
2015 Lecture Notes in Computer Science  
This tractability result has been extended to several tasks related to query evaluation, such as counting query results [3] or performing query evaluation on probabilistic trees [10].  ...  These are two examples of the more general problem of computing augmented query output, that is referred to as provenance.  ...  Navigational Queries Conjunctive two-way regular path queries (C2RPQs) generalize conjunctive queries (CQs) by regular expressions over binary predicates [Florescu et al., 1998; Calvanese et al., 2003  ... 
doi:10.1007/978-3-662-47666-6_5 fatcat:dpatpbav7fgblnbvfsx6dbr6k4

Access patterns and integrity constraints revisited

Vince Bárány, Michael Benedikt, Pierre Bourhis
2013 Proceedings of the 16th International Conference on Database Theory - ICDT '13  
Our results relate querying with limited access patterns, determinacy-vsrewriting, and analysis of guarded constraints.  ...  We show that answerability is decidable for the class of guarded dependencies, which includes all inclusion dependencies, and also for constraints given in the guarded fragment of first-order logic.  ...  There are conjunctive queries that are not FO access certain-answer rewritable over guarded constraints. Proof.  ... 
doi:10.1145/2448496.2448522 dblp:conf/icdt/BaranyBB13 fatcat:aexm4ssya5fkbl5jteqnfwixtq

Faceted Search over Ontology-Enhanced RDF Data

Marcelo Arenas, Bernardo Cuenca Grau, Evgeny Kharlamov, Sarunas Marciuska, Dmitriy Zheleznyakov
2014 Proceedings of the 23rd ACM International Conference on Conference on Information and Knowledge Management - CIKM '14  
We formalise faceted interfaces for this context, identify a fragment of first-order logic capturing the underlying queries, and study the complexity of answering such queries for RDF and OWL 2 profiles  ...  An increasing number of applications rely on RDF, OWL 2, and SPARQL for storing and querying data. SPARQL, however, is not targeted towards end-users, and suitable query interfaces are needed.  ...  Branching (path 1 • path 2 ) with • ∈ {∧, ∨} is interpreted by constructing the conjunction (disjunction) of the queries for each path i ; furthermore, if for some path i we have that path i , v, xw =  ... 
doi:10.1145/2661829.2662027 dblp:conf/cikm/ArenasGKMZ14 fatcat:7crqtm47endwpnlmasavgt7xne

Ontologies and Data Management: A Brief Survey

Thomas Schneider, Mantas Šimkus
2020 Künstliche Intelligenz  
Baget J, Bienvenu M, Mugnier M, Thomazo M (2017) Answering conjunctive regular path queries over guarded existential rules.  ...  Navigational queries like regular path queries (RPQs) in graph databases allow to specify complex paths by means of regular expressions built from roles [2, 104] .  ... 
doi:10.1007/s13218-020-00686-3 pmid:32999532 pmcid:PMC7497697 fatcat:zeskjfjrpvcojjh6q3yjzhlyci

On the Complexity of Evaluating Regular Path Queries over Linear Existential Rules [chapter]

Meghyn Bienvenu, Michaël Thomazo
2016 Lecture Notes in Computer Science  
existential rules.  ...  In this paper, we investigate the complexity of evaluating the standard form of navigational queries, namely two-way regular path queries, over knowledge bases whose ontology is expressed by means of linear  ...  A two-way regular path query (RPQ 3 ) is a query of the form q(x, x ) = E(x, x ), where E is a regular expression defining a language over P r .  ... 
doi:10.1007/978-3-319-45276-0_1 fatcat:y6z76z5kxrd7tdnzdv5bsurj2e

Query Processing in Data Integration

Paolo Guagliardo, Piotr Wieczorek, Marc Herbstritt
2013 Dagstuhl Publications  
in traditional database systems allows to point out the subtle differences between query answering and query rewriting.  ...  The first part of the chapter focuses on the problem of query answering in the relational setting, and describes approaches based on variants of the chase, along with how to deal with integrity constraints  ...  A regular-path query (RPQ) is a binary query defined in terms of a regular language over R.  ... 
doi:10.4230/dfu.vol5.10452.129 dblp:conf/dagstuhl/GuagliardoW13 fatcat:2bqbnhu3wbe3rcvsck6aqzr3em

Knowing When to Ask: Sound scheduling of name resolution in type checkers derived from declarative specifications (Extended Version)

Arjen Rouvoet, Hendrik van Antwerpen, Casper Bach Poulsen, Robbert Krebbers, Eelco Visser
2020 Zenodo  
This requires scheduling those two aspects in such a way that query answers are stable---i.e., they are computed only after all relevant binding structure has been collected.  ...  This yields type checkers for the specified languages that are sound by construction---i.e., they schedule queries so that the answers are stable, and only accept programs that are name- and type-correct  ...  Regular paths. Name resolution is modeled with regular paths in the graph.  ... 
doi:10.5281/zenodo.4091445 fatcat:34x4yv7fb5gd5h3lmtlocds3gq

Query Containment for Highly Expressive Datalog Fragments [article]

Pierre Bourhis and Markus Krötzsch and Sebastian Rudolph
2014 arXiv   pre-print
We generalize MQs to (Frontier-)Guarded Queries (GQs), and show that the containment problem is 3ExpTime-complete in either case, even if we allow arbitrary Datalog in the sub-query.  ...  There are, however, several Datalog fragments for which containment is known to be decidable, most notably monadic Datalog and several "regular" query languages on graphs.  ...  Conjunctive two-way regular path queries (C2RPQs) generalize conjunctive queries (CQs) by regular expressions over binary predicates [18, 9] .  ... 
arXiv:1406.7801v1 fatcat:cn5rocfztfg5rhey4kgsexu5o4

Ontologies for Knowledge Graphs: Breaking the Rules [chapter]

Markus Krötzsch, Veronika Thost
2016 Lecture Notes in Computer Science  
We study this issue for several classes of existential rules and derive new syntactic criteria to recognise well-behaved rule-based ontologies over KGs.  ...  Frontier Guardedness and Functional Attributes Our denormalisation procedure can also be applied to KG frontier guarded rules. Theorem 8.  ...  However, we cannot just introduce FDs as additional rules: query answering is undecidable for the combination of (frontier) guarded existential rules and FDs [15] .  ... 
doi:10.1007/978-3-319-46523-4_23 fatcat:i3jgivfb75hdbdohmocj34svfa

Knowing when to ask: sound scheduling of name resolution in type checkers derived from declarative specifications

Arjen Rouvoet, Hendrik van Antwerpen, Casper Bach Poulsen, Robbert Krebbers, Eelco Visser
2020 Proceedings of the ACM on Programming Languages (PACMPL)  
This requires scheduling those two aspects in such a way that query answers are stableÐi.e., they are computed only after all relevant binding structure has been collected.  ...  This yields type checkers for the specified languages that are sound by constructionÐi.e., they schedule queries so that the answers are stable, and only accept programs that are name-and type-correct  ...  We then prove the following guarded query simplification rule correct: Op-Query-Guarded ∀ 2 , .  ... 
doi:10.1145/3428248 fatcat:62llickevjabtnyjdjftona2z4

Loop Restricted Existential Rules and First-order Rewritability for Query Answering [article]

Vernon Asuncion, Yan Zhang, Heng Zhang, Yun Bai, Weisheng Si
2018 arXiv   pre-print
We show that the conjunctive query answering (CQA) under the LR TGDs is decid- able.  ...  A powerful form of such logical assertions is the tuple-generating dependencies (TGDs), also called existential rules, where Horn rules are extended by allowing existential quantifiers to appear in the  ...  The answer to a BCQ is positive over I, denoted as I |= q, if ∈ q(I). TGDs and conjunctive query answering (CQA).  ... 
arXiv:1804.07099v2 fatcat:np27waymgza3zhbjz4mppxyysy
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