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Taming the Infinite Chase: Query Answering under Expressive Relational Constraints

A. Calì, G. Gottlob, M. Kifer
2013 The Journal of Artificial Intelligence Research  
Nevertheless, we prove that the problems of conjunctive-query answering and query containment under such TGDs are decidable.  ...  For these classes, the chase procedure is not guaranteed to terminate and thus may have an infinite outcome.  ...  Query Answering and the Chase The problems of query containment and answering under TGDs are closely related to each other and to the notion of chase, as explained below.  ... 
doi:10.1613/jair.3873 fatcat:lyniplyrmjg75jgz47ddbgbf2e

Distribution Constraints: The Chase for Distributed Data [article]

Gaetano Geck, Frank Neven, Thomas Schwentick
2020 arXiv   pre-print
These results yield bounds on deciding parallel-correctness for conjunctive queries in the presence of distribution constraints.  ...  In particular, they can express co-partitioning constraints and constraints about range-based data distributions by using comparison atoms.  ...  The space-efficient core of vadalog. CoRR, abs/1809.05951, 2018. 17 A. Calì, G. Gottlob, and M. Kifer. Taming the infinite chase: Query answering under expressive relational constraints. J. Artif.  ... 
arXiv:2003.00965v1 fatcat:qdiyqrxtc5ctbcx5ht2gqxgr4q

Querying Visible and Invisible Information

Michael Benedikt, Pierre Bourhis, Balder ten Cate, Gabriele Puppis
2016 Proceedings of the 31st Annual ACM/IEEE Symposium on Logic in Computer Science - LICS '16  
We also have integrity constraints (invariants given by logical sentences) which may relate the visible relations to the invisible ones.  ...  We want to determine which information about a query (a positive existential sentence) can be inferred from the visible instance and the constraints.  ...  Benedikt's work was sponsored by the Engineering and Physical Sciences Research Council of the United Kingdom, grants EP/M005852/1 and EP/L012138/1.  ... 
doi:10.1145/2933575.2935306 dblp:conf/lics/BenediktBCP16 fatcat:qlv32v7ftrfxfhvd6xfyjzhvqe

When Can We Answer Queries Using Result-Bounded Data Interfaces? [article]

Antoine Amarilli, Michael Benedikt
2022 arXiv   pre-print
We study how to decide if a query is answerable using result-bounded methods, i.e., how to compute a plan that returns all answers to the query using the methods, assuming that the underlying data satisfies  ...  We first show how to reduce answerability to a query containment problem with constraints.  ...  We are grateful to the journal reviewers for a multitude of helpful comments, and in particularly for noticing some significant flaws in the arguments of the conference version [AB18a] .  ... 
arXiv:1810.07822v4 fatcat:hkdhprgrhbac7ijh3a5bbl7hz4

Generating low-cost plans from proofs

Michael Benedikt, Balder ten Cate, Efthymia Tsamoura
2014 Proceedings of the 33rd ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems - PODS '14  
Our method can exploit the integrity constraints to find low-cost access plans even when there is no direct access to relations appearing in the query.  ...  We look at generating plans that answer queries over restricted interfaces, making use of information about source integrity constraints, access restrictions, and access costs.  ...  We want to emphasize that this approach does not depend on any acyclicity condition on the constraints -thus the set of possible chase sequences can be infinite.  ... 
doi:10.1145/2594538.2594550 dblp:conf/pods/BenediktCT14 fatcat:fq3n4rafljd6pmnvjjzw5pz4pq

Generating Plans from Proofs

Michael Benedikt, Balder Ten Cate, Efthymia Tsamoura
2016 ACM Transactions on Database Systems  
Our method can exploit the integrity constraints to find plans even when there is no direct access to relations appearing in the query.  ...  We present algorithms for answering queries making use of information about source integrity constraints, access restrictions, and access costs.  ...  We will show that for "tame" constraints classes, answerability over all instances and answerability over finite instances coincide, and in particular the characterization theorems and algorithms relating  ... 
doi:10.1145/2847523 fatcat:szrzwhessvhs5coqcsebtwqeva

Data exchange with arithmetic operations

Balder ten Cate, Phokion G. Kolaitis, Walied Othman
2013 Proceedings of the 16th International Conference on Extending Database Technology - EDBT '13  
We obtain analogous complexity results for the data complexity of computing the certain answers of arithmetic conjunctive queries and linear arithmetic conjunctive queries.  ...  Data exchange is the problem of transforming data structured under a source schema into data structured under a target schema, taking into account structural relationships between the two schemas, which  ...  There are, however, important applications in which this language cannot express the required constraints.  ... 
doi:10.1145/2452376.2452439 dblp:conf/edbt/CateKO13 fatcat:rt5ah3lhrbfylonbwhjcupjsfm

Swift Logic for Big Data and Knowledge Graphs [chapter]

Luigi Bellomarini, Georg Gottlob, Andreas Pieris, Emanuel Sallinger
2017 Lecture Notes in Computer Science  
Many modern companies wish to maintain knowledge in the form of a corporate knowledge graph and to use and manage this knowledge via a knowledge graph management system (KGMS).  ...  Moreover, a KGMS needs interfaces to corporate databases, the web, and machinelearning and analytics packages. We present KRR formalisms and a system achieving these goals.  ...  This work has been supported by the EPSRC Programme Grant EP/M025268/1. The VADALOG system as presented here is the intellectual property of the University of Oxford.  ... 
doi:10.1007/978-3-319-73117-9_1 fatcat:kplzy4npfbeczixmten2iaaolu

Balancing Expressiveness and Inexpressiveness in View Design

Michael Benedikt, Pierre Bourhis, Louis Jachiet, Efthymia Tsamoura
2020 Proceedings of the Seventeenth International Conference on Principles of Knowledge Representation and Reasoning  
The views must be sufficiently expressive to support queries that users want to ask -- the utility of the publishing mechanism. But there may also be some expressiveness restriction.  ...  We investigate the problem of designing views that satisfy both an expressiveness and an inexpressiveness requirement, for views in a restricted declarative language (conjunctive queries), and for arbitrary  ...  Our expressiveness requirement (or usefulness) will be phrased in terms of the ability to answer, using only the information exposed by the views, a relational query -the "utility query" that the parties  ... 
doi:10.24963/kr.2020/12 dblp:conf/kr/BenediktBJT20 fatcat:lxzmku7khraszizipprs6i5u34

Query Answering with Guarded Existential Rules under Stable Model Semantics

Hai Wan, Guohui Xiao, Chenglin Wang, Xianqiao Liu, Junhong Chen, Zhe Wang
2020 PROCEEDINGS OF THE THIRTIETH AAAI CONFERENCE ON ARTIFICIAL INTELLIGENCE AND THE TWENTY-EIGHTH INNOVATIVE APPLICATIONS OF ARTIFICIAL INTELLIGENCE CONFERENCE  
In this paper, we study the problem of query answering with guarded existential rules (also called GNTGDs) under stable model semantics.  ...  Using these notions, we prove that the ground termination problem for GNTGDs is decidable. We also devise an algorithm for query answering with GNTGDs using ASP solvers.  ...  We call i≥0 I i the result of this chase sequence. We denote by chase(I, Σ) the result of an arbitrary chase sequence for I under Σ.  ... 
doi:10.1609/aaai.v34i03.5695 fatcat:4pr2me7paja3hbsqclft4q3vw4

The Space-Efficient Core of Vadalog

Gerald Berger, Georg Gottlob, Andreas Pieris, Emanuel Sallinger
2019 Proceedings of the 38th ACM SIGMOD-SIGACT-SIGAI Symposium on Principles of Database Systems - PODS '19  
We finally study the relative expressiveness of the query languages based on (piece-wise linear) warded sets of TGDs.  ...  We show that this type of recursion, known as piecewise linear in the Datalog literature, is the answer to our main question.  ...  expressive power.  ... 
doi:10.1145/3294052.3319688 dblp:conf/pods/BergerGPS19 fatcat:rggpmw6rlze6racb45ttgnurxu

Balancing expressiveness and inexpressiveness in view design [article]

Michael Benedikt and Pierre Bourhis and Louis Jachiet and Efthymia Tsamoura
2020 arXiv   pre-print
The views must be sufficiently expressive to support queries that users want to ask -- the utility of the publishing mechanism. But there may also be some expressiveness restriction.  ...  We investigate the problem of designing views that satisfy both an expressiveness and an inexpressiveness requirement, for views in a restricted declarative language (conjunctive queries), and for arbitrary  ...  Our expressiveness requirement (usefulness) will be phrased in terms of the ability to answer a relational query, where answering is the traditional deterministic notion used in database theory and knowledge  ... 
arXiv:2006.00875v2 fatcat:53i7yqg5bffzhepcecszgdczq4

The Space-Efficient Core of Vadalog [article]

Gerald Berger, Georg Gottlob, Andreas Pieris, Emanuel Sallinger
2018 arXiv   pre-print
We finally study the relative expressiveness of the query languages based on (piece-wise linear) warded sets of TGDs.  ...  We show that this type of recursion, known as piece-wise linear in the Datalog literature, is the answer to our main question.  ...  Query Answering under TGDs. The main reasoning task under TGD-based languages is conjunctive query answering.  ... 
arXiv:1809.05951v1 fatcat:5jggqx4ivfdrtb5exywxcxwwjq

Some Model Theory of Guarded Negation [article]

Vince Barany, Michael Benedikt, Balder ten Cate
2020 arXiv   pre-print
Our results include effective preservation theorems for GNFO, effective Craig Interpolation and Beth Definability results, and the ability to express the certain answers of queries with respect to a large  ...  The Guarded Negation Fragment (GNFO) is a fragment of first-order logic that contains all positive existential formulas, can express the first-order translations of basic modal logic and of many description  ...  We also thank the anonymous reviewers of the Journal of Symbolic Logic for their patient reading of the manuscript and helpful corrections.  ... 
arXiv:2005.06299v2 fatcat:awujhhdh6bgrrgs3xu3v7igz4u

Inference from Visible Information and Background Knowledge

Michael Benedikt, Pierre Bourhis, Balder Ten Cate, Gabrieled Puppis, Michael Vanden Boom
2021 ACM Transactions on Computational Logic  
of the query can be inferred in some instance of the schema.  ...  We provide a wide-ranging study of the scenario where a subset of the relations in a relational vocabulary is visible to a user—that is, their complete contents are known—while the remaining relations  ...  [15, 16] analyzed the complexity of query implication in the presence of information disclosure methods based on query answering interfaces -where an external user can query under the certain answer  ... 
doi:10.1145/3452919 fatcat:2j244ukosvb2tbmln4rr343nau
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