The monotone circuit complexity of Boolean functions
Combinatorica
Partial evaluation in logic programming
Journal of Logic Programming
Monotone circuits for matching require linear depth
Journal of the ACM (JACM)
Monotone separation of logarithmic space from logarithmic depth
Journal of Computer and System Sciences
On the complexity of database queries (extended abstract)
PODS '97 Proceedings of the sixteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Explicit lower bound of 4.5n - o(n) for boolena circuits
STOC '01 Proceedings of the thirty-third annual ACM symposium on Theory of computing
When is the evaluation of conjunctive queries tractable?
STOC '01 Proceedings of the thirty-third annual ACM symposium on Theory of computing
Data integration: a theoretical perspective
Proceedings of the twenty-first ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Foundations of Databases: The Logical Level
Foundations of Databases: The Logical Level
Computers and Intractability: A Guide to the Theory of NP-Completeness
Computers and Intractability: A Guide to the Theory of NP-Completeness
Separation of the monotone NC hierarchy
FOCS '97 Proceedings of the 38th Annual Symposium on Foundations of Computer Science
Elements Of Finite Model Theory (Texts in Theoretical Computer Science. An Eatcs Series)
Elements Of Finite Model Theory (Texts in Theoretical Computer Science. An Eatcs Series)
Theory of Computation (Texts in Computer Science)
Theory of Computation (Texts in Computer Science)
Tractable Reasoning and Efficient Query Answering in Description Logics: The DL-Lite Family
Journal of Automated Reasoning
Reasoning in Description Logics by a Reduction to Disjunctive Datalog
Journal of Automated Reasoning
Fast parallel matrix and GCD computations
SFCS '82 Proceedings of the 23rd Annual Symposium on Foundations of Computer Science
Data Complexity of Query Answering in Expressive Description Logics via Tableaux
Journal of Automated Reasoning
The Complexity of Conjunctive Query Answering in Expressive Description Logics
IJCAR '08 Proceedings of the 4th international joint conference on Automated Reasoning
Economy of description by automata, grammars, and formal systems
SWAT '71 Proceedings of the 12th Annual Symposium on Switching and Automata Theory (swat 1971)
Scalable Grounded Conjunctive Query Evaluation over Large and Expressive Knowledge Bases
ISWC '08 Proceedings of the 7th International Conference on The Semantic Web
Computational Complexity: A Modern Approach
Computational Complexity: A Modern Approach
Conjunctive query answering for the description logic SHIQ
Journal of Artificial Intelligence Research
Conjunctive query answering in the description logic EL using a relational database system
IJCAI'09 Proceedings of the 21st international jont conference on Artifical intelligence
The DL-lite family and relations
Journal of Artificial Intelligence Research
Journal on data semantics X
Fundamentals of Database Systems
Fundamentals of Database Systems
Ontological queries: Rewriting and optimization
ICDE '11 Proceedings of the 2011 IEEE 27th International Conference on Data Engineering
Optimized query rewriting for OWL 2 QL
CADE'11 Proceedings of the 23rd international conference on Automated deduction
Conjunctive query answering in the description logic SH using knots
Journal of Computer and System Sciences
View-based query answering in Description Logics: Semantics and complexity
Journal of Computer and System Sciences
Boolean Function Complexity: Advances and Frontiers
Boolean Function Complexity: Advances and Frontiers
A general Datalog-based framework for tractable query answering over ontologies
Web Semantics: Science, Services and Agents on the World Wide Web
Query answering in the horn fragments of the description logics SHOIQ and SROIQ
IJCAI'11 Proceedings of the Twenty-Second international joint conference on Artificial Intelligence - Volume Volume Two
The combined approach to ontology-based data access
IJCAI'11 Proceedings of the Twenty-Second international joint conference on Artificial Intelligence - Volume Volume Three
Prexto: query rewriting under extensional constraints in DL-lite
ESWC'12 Proceedings of the 9th international conference on The Semantic Web: research and applications
Exponential lower bounds and separation for query rewriting
ICALP'12 Proceedings of the 39th international colloquium conference on Automata, Languages, and Programming - Volume Part II
Towards more expressive ontology languages: The query answering problem
Artificial Intelligence
A sound and complete backward chaining algorithm for existential rules
RR'12 Proceedings of the 6th international conference on Web Reasoning and Rule Systems
Ontology-based data access: a study through disjunctive datalog, CSP, and MMSNP
Proceedings of the 32nd symposium on Principles of database systems
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Ontology-based data access (OBDA) is regarded as a key ingredient of the new generation of information systems. In the OBDA paradigm, an ontology defines a high-level global schema of (already existing) data sources and provides a vocabulary for user queries. An OBDA system rewrites such queries and ontologies into the vocabulary of the data sources and then delegates the actual query evaluation to a suitable query answering system such as a relational database management system or a datalog engine. In this chapter, we mainly focus on OBDA with the ontology language OWL 2QL, one of the three profiles of the W3C standard Web Ontology Language OWL 2, and relational databases, although other possible languages will also be discussed. We consider different types of conjunctive query rewriting and their succinctness, different architectures of OBDA systems, and give an overview of the OBDA system Ontop.