Theoretical Computer Science
On conjunctive queries containing inequalities
Journal of the ACM (JACM)
Foundations of deductive databases and logic programming
Decidable optimization problems for database logic programs
STOC '88 Proceedings of the twentieth annual ACM symposium on Theory of computing
Equivalence of datalog queries is undecidable
Journal of Logic Programming
The complexity of querying indefinite information: defined relations, recursion and linear order
The complexity of querying indefinite information: defined relations, recursion and linear order
On the complexity of equivalence between recursive and nonrecursive Datalog programs
PODS '94 Proceedings of the thirteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Subsumption between queries to object-oriented databases
Information Systems - Special issue on extending database technology
Semantic query optimization in Datalog programs (extended abstract)
PODS '95 Proceedings of the fourteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Query caching and optimization in distributed mediator systems
SIGMOD '96 Proceedings of the 1996 ACM SIGMOD international conference on Management of data
A query language and optimization techniques for unstructured data
SIGMOD '96 Proceedings of the 1996 ACM SIGMOD international conference on Management of data
Panorama: a database system that annotates its answers to queries with their properties
Journal of Intelligent Information Systems
PODS '97 Proceedings of the sixteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Reasoning in description logics
Principles of knowledge representation
Query containment for conjunctive queries with regular expressions
PODS '98 Proceedings of the seventeenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Database techniques for the World-Wide Web: a survey
ACM SIGMOD Record
Navigational plans for data integration
AAAI '99/IAAI '99 Proceedings of the sixteenth national conference on Artificial intelligence and the eleventh Innovative applications of artificial intelligence conference innovative applications of artificial intelligence
On the foundations of the universal relation model
ACM Transactions on Database Systems (TODS)
Equivalences Among Relational Expressions with the Union and Difference Operators
Journal of the ACM (JACM)
Data on the Web: from relations to semistructured data and XML
Data on the Web: from relations to semistructured data and XML
Regular path queries with constraints
Journal of Computer and System Sciences
Foundations of Databases: The Logical Level
Foundations of Databases: The Logical Level
Optimizing Queries with Materialized Views
ICDE '95 Proceedings of the Eleventh International Conference on Data Engineering
Index Structures for Path Expressions
ICDT '99 Proceedings of the 7th International Conference on Database Theory
Verifying Integrity Constraints on Web Sites
IJCAI '99 Proceedings of the Sixteenth International Joint Conference on Artificial Intelligence
Optimal implementation of conjunctive queries in relational data bases
STOC '77 Proceedings of the ninth annual ACM symposium on Theory of computing
Elementary induction on abstract structures (Studies in logic and the foundations of mathematics)
Elementary induction on abstract structures (Studies in logic and the foundations of mathematics)
Tree acceptors and some of their applications
Journal of Computer and System Sciences
Verification of knowledge bases based on containment checking
AAAI'96 Proceedings of the thirteenth national conference on Artificial intelligence - Volume 1
ACM SIGMOD Record
On the decidability of containment of recursive datalog queries - preliminary report
PODS '04 Proceedings of the twenty-third ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Declarative routing: extensible routing with declarative queries
Proceedings of the 2005 conference on Applications, technologies, architectures, and protocols for computer communications
Equivalence of queries combining set and bag-set semantics
Proceedings of the twenty-fifth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Declarative networking: language, execution and optimization
Proceedings of the 2006 ACM SIGMOD international conference on Management of data
Deciding equivalences among conjunctive aggregate queries
Journal of the ACM (JACM)
On Simplification of Database Integrity Constraints
Fundamenta Informaticae
Conjunctive query containment and answering under description logic constraints
ACM Transactions on Computational Logic (TOCL)
Type inference for datalog and its application to query optimisation
Proceedings of the twenty-seventh ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Equivalence of queries that are sensitive to multiplicities
The VLDB Journal — The International Journal on Very Large Data Bases
Containment of conjunctive queries over databases with null values
ICDT'07 Proceedings of the 11th international conference on Database Theory
Hidden conditioned homomorphism for XPath fragment containment
DASFAA'06 Proceedings of the 11th international conference on Database Systems for Advanced Applications
On Simplification of Database Integrity Constraints
Fundamenta Informaticae
Hi-index | 0.00 |
One of the most important reasoning tasks on queries is checking containment, i.e., verifying whether one query yields necessarily a subset of the result of another one. Query containment, is crucial in several contexts, such as query optimization, query reformulation, knowledge-base verification, information integration, integrity checking, and cooperative answering. Containment is undecidable in general for Datalog, the fundamental language for expressing recursive queries. On the other hand, it is known that containment between monadic Datalog queries and between Datalog queries and unions of conjunctive queries are decidable. It is also known that containment between unions of conjunctive two-way regular path queries (UC2RPQs), which are queries used in the context of semistructured data models containing a limited form of recursion in the form of transitive closure, is decidable. In this paper we combine the automata-theoretic techniques at the base of these two decidability results to show that containment of Datalog in UC2RPQs is decidable in 2EXPTIME.