Automata-Theoretic techniques for modal logics of programs
Journal of Computer and System Sciences
A query language and optimization techniques for unstructured data
SIGMOD '96 Proceedings of the 1996 ACM SIGMOD international conference on Management of data
PODS '97 Proceedings of the sixteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Regular path queries with constraints
PODS '97 Proceedings of the sixteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
World Wide Web Journal - Special issue on XML: principles, tools, and techniques
Path constraints on semistructured and structured data
PODS '98 Proceedings of the seventeenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
What can knowledge representation do for semi-structured data?
AAAI '98/IAAI '98 Proceedings of the fifteenth national/tenth conference on Artificial intelligence/Innovative applications of artificial intelligence
Interaction between path and type constraints
PODS '99 Proceedings of the eighteenth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
WWW '99 Proceedings of the eighth international conference on World Wide Web
Path constraints in semistructured databases
Journal of Computer and System Sciences - Special issue on the seventeenth ACM SIGACT-SIGMOD-SIGART symposium on principles of database systems
Foundations of Databases: The Logical Level
Foundations of Databases: The Logical Level
ICDT '97 Proceedings of the 6th International Conference on Database Theory
An Equational Chase for Path-Conjunctive Queries, Constraints, and Views
ICDT '99 Proceedings of the 7th International Conference on Database Theory
Reasoning in expressive description logics
Handbook of automated reasoning
Interactive Query Formulation in Semistructured Databases
FQAS '02 Proceedings of the 5th International Conference on Flexible Query Answering Systems
Foundations of rule-based query answering
RW'07 Proceedings of the Third international summer school conference on Reasoning Web
Definability problems for graph query languages
Proceedings of the 16th International Conference on Database Theory
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Path constraints have been studied for semistructured data modeled as a rooted edge-labeled directed graph [4, 11-13]. In this model, the implication problems associated with many natural path constraints are undecidable [11, 13]. A variant of the graph model, called the deterministic data model, was recently proposed in [10]. In this model, data is represented as a graph with deterministic edge relations, i.e., the edges emanating from any node in the graph have distinct labels. This model is more appropriate for representing, e.g., ACeDB [27] databases and Web sites. This paper investigates path constraints for the deterministic data model. It demonstrates the application of path constraints to, among others, query optimization. Three classes of path constraints are considered: the language Pc introduced in [11], an extension of Pc, denoted by Pcw, by including wildcards in path expressions, and a generalization of Pcw, denoted by P*c, by representing paths as regular expressions. The implication problems for these constraint languages are studied in the context of the deterministic data model. It is shown that in contrast to the undecidability result of [11], the implication and finite implication problems for Pc are decidable in cubic-time and are finitely axiomatizable. Moreover, the implication problems are decidable for Pcw. However, the implication problems for P*c are undecidable.