On conjunctive queries containing inequalities
Journal of the ACM (JACM)
POPL '88 Proceedings of the 15th ACM SIGPLAN-SIGACT symposium on Principles of programming languages
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
Answering queries using views (extended abstract)
PODS '95 Proceedings of the fourteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
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
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
Complexity of answering queries using materialized views
PODS '98 Proceedings of the seventeenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Rewriting of regular expressions and regular path queries
PODS '99 Proceedings of the eighteenth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
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
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
View-based query processing for regular path queries with inverse
PODS '00 Proceedings of the nineteenth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Query containment for data integration systems
PODS '00 Proceedings of the nineteenth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Theory of answering queries using views
ACM SIGMOD Record
Data integration: a theoretical perspective
Proceedings of the twenty-first ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Proceedings of the twenty-first ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Introduction To Automata Theory, Languages, And Computation
Introduction To Automata Theory, Languages, And Computation
Computers and Intractability: A Guide to the Theory of NP-Completeness
Computers and Intractability: A Guide to the Theory of NP-Completeness
Optimizing Queries with Materialized Views
ICDE '95 Proceedings of the Eleventh International Conference on Data Engineering
Information Integration Using Logical Views
ICDT '97 Proceedings of the 6th International Conference on Database Theory
View-Based Query Answering and Query Containment over Semistructured Data
DBPL '01 Revised Papers from the 8th International Workshop on Database Programming Languages
Optimization Properties for Classes of Conjunctive Regular Path Queries
DBPL '01 Revised Papers from the 8th International Workshop on Database Programming Languages
Answering queries using views: A survey
The VLDB Journal — The International Journal on Very Large Data Bases
Proceedings of the twenty-second ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Query containment and rewriting using views for regular path queries under constraints
Proceedings of the twenty-second ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
View-Based Query Processing and Constraint Satisfaction
LICS '00 Proceedings of the 15th Annual IEEE Symposium on Logic in Computer Science
The complexity of relational query languages (Extended Abstract)
STOC '82 Proceedings of the fourteenth annual ACM symposium on Theory of computing
Optimal implementation of conjunctive queries in relational data bases
STOC '77 Proceedings of the ninth annual ACM symposium on Theory of computing
Verification of knowledge bases based on containment checking
AAAI'96 Proceedings of the thirteenth national conference on Artificial intelligence - Volume 1
Journal of Computer and System Sciences
View-based query processing: On the relationship between rewriting, answering and losslessness
Theoretical Computer Science
Fault-tolerant computation of distributed regular path queries
Theoretical Computer Science
An Automata-Theoretic Approach to Regular XPath
DBPL '09 Proceedings of the 12th International Symposium on Database Programming Languages
Proceedings of the 14th International Conference on Database Theory
Complexity of Decision Problems for XML Schemas and Chain Regular Expressions
SIAM Journal on Computing
PADL'06 Proceedings of the 8th international conference on Practical Aspects of Declarative Languages
View-based query processing: on the relationship between rewriting, answering and losslessness
ICDT'05 Proceedings of the 10th international conference on Database Theory
Regular languages with variables on graphs
Information and Computation
Containment of regular path queries under description logic constraints
IJCAI'11 Proceedings of the Twenty-Second international joint conference on Artificial Intelligence - Volume Volume Two
Datalog as a lingua franca for provenance querying and reasoning
TaPP'12 Proceedings of the 4th USENIX conference on Theory and Practice of Provenance
Distributed multi-source regular path queries
ISPA'07 Proceedings of the 2007 international conference on Frontiers of High Performance Computing and Networking
Walk logic as a framework for path query languages on graph databases
Proceedings of the 16th International Conference on Database Theory
Query processing under GLAV mappings for relational and graph databases
Proceedings of the VLDB Endowment
Proceedings of the 32nd symposium on Principles of database systems
Flag & check: data access with monadically defined queries
Proceedings of the 32nd symposium on Principles of database systems
A trichotomy for regular simple path queries on graphs
Proceedings of the 32nd symposium on Principles of database systems
On simplification of schema mappings
Journal of Computer and System Sciences
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Current information systems are required to deal with more complex data with respect to traditional relational data. The database community has already proposed abstractions for these kinds of data, in particular in terms of semistructured data models. A semistructured model conceives a database essentially as a finite directed labeled graph whose nodes represent objects, and whose edges represent relationships between objects. In the same way as conjunctive queries form the core of any query language for the relational model, regular path queries (RPQs) and their variants are considered the basic querying mechanisms for semistructured data.Besides the basic task of query answering, i.e., evaluating a query over a database, databases should support other reasoning services related to querying. One of the most important is query containment, i.e., verifying whether for all databases the answer to a query is a subset of the answer to a second query. Another important reasoning service that has received considerable attention in the recent years is view-based query processing, which amounts to processing queries based on a set of materialized views, rather than on the raw data in the database.The goal of this paper is to describe basic results and techniques concerning query containment and view based query processing for the class of two-way regular-path queries (which extend RPQs with the inverse operator). We will demonstrate that the basic services for reasoning about two way regular path queries are decidable, thus showing that the limited form of recursion expressible by these queries does not endanger the decidability of reasoning. Besides the specific results, our methods show the power of two-way automata in reasoning on complex queries.