Journal of Computer and System Sciences
Invited talk: automata theory for database theoreticians
PODS '89 Proceedings of the eighth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Graph rewriting: an algebraic and logic approach
Handbook of theoretical computer science (vol. B)
Retrieval from hierarchical texts by partial patterns
SIGIR '93 Proceedings of the 16th annual international ACM SIGIR conference on Research and development in information retrieval
Information Processing Letters
A Grammar-Based Approach Towards Unifying Hierarchical Data Models
SIAM Journal on Computing
Complexity results for two-way and multi-pebble automata and their logics
ICALP '94 Selected papers from the 21st international colloquium on Automata, languages and programming
Handbook of formal languages, vol. 3: beyond words
Handbook of formal languages, vol. 3: beyond words
Handbook of formal languages, vol. 3
Languages, automata, and logic
Handbook of formal languages, vol. 3
Expressiveness of structured document query languages based on attribute grammars
PODS '98 Proceedings of the seventeenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
WWW '99 Proceedings of the eighth international conference on World Wide Web
Data on the Web: from relations to semistructured data and XML
Data on the Web: from relations to semistructured data and XML
MSO definable string transductions and two-way finite-state transducers
ACM Transactions on Computational Logic (TOCL)
Integrating contents and structure in text retrieval
ACM SIGMOD Record
Foundations of Databases: The Logical Level
Foundations of Databases: The Logical Level
Modern Information Retrieval
Introduction To Automata Theory, Languages, And Computation
Introduction To Automata Theory, Languages, And Computation
Mind Your Grammar: a New Approach to Modelling Text
VLDB '87 Proceedings of the 13th International Conference on Very Large Data Bases
Ehrenfeucht Games, the Composition Method, and the Monadic Theory of Ordinal Words
Structures in Logic and Computer Science, A Selection of Essays in Honor of Andrzej Ehrenfeucht
Numeration Systems, Linear Recurrences, and Regular Sets (Extended Abstract)
ICALP '92 Proceedings of the 19th International Colloquium on Automata, Languages and Programming
Locating Matches of Tree Patterns in Forests
Proceedings of the 18th Conference on Foundations of Software Technology and Theoretical Computer Science
Query Primitives for Tree-Structured Data
CPM '94 Proceedings of the 5th Annual Symposium on Combinatorial Pattern Matching
A logical view of structured files
The VLDB Journal — The International Journal on Very Large Data Bases
Monadic datalog and the expressive power of languages for web information extraction
Proceedings of the twenty-first ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Automata theory for XML researchers
ACM SIGMOD Record
Typechecking Top-Down Uniform Unranked Tree Transducers
ICDT '03 Proceedings of the 9th International Conference on Database Theory
Logic as a Query Language: From Frege to XML
STACS '03 Proceedings of the 20th Annual Symposium on Theoretical Aspects of Computer Science
CSL '02 Proceedings of the 16th International Workshop and 11th Annual Conference of the EACSL on Computer Science Logic
XPath Containment in the Presence of Disjunction, DTDs, and Variables
ICDT '03 Proceedings of the 9th International Conference on Database Theory
Proceedings of the twenty-second ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Query-preserving watermarking of relational databases and XML documents
Proceedings of the twenty-second ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
A Web odyssey: from codd to XML
ACM SIGMOD Record
Monadic datalog and the expressive power of languages for Web information extraction
Journal of the ACM (JACM)
Finite state machines for strings over infinite alphabets
ACM Transactions on Computational Logic (TOCL)
Logic-based web information extraction
ACM SIGMOD Record
The Lixto data extraction project: back and forth between theory and practice
PODS '04 Proceedings of the twenty-third ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Attribute grammars for unranked trees as a query language for structured documents
Journal of Computer and System Sciences
On the complexity of typechecking top-down XML transformations
Theoretical Computer Science - Database theory
Interactive learning of node selecting tree transducer
Machine Learning
Journal of Computer and System Sciences
Logical definability and query languages over ranked and unranked trees
ACM Transactions on Computational Logic (TOCL)
On the minimization of XML Schemas and tree automata for unranked trees
Journal of Computer and System Sciences
Tight lower bounds for query processing on streaming and external memory data
Theoretical Computer Science
Expressiveness and complexity of xml publishing transducers
Proceedings of the twenty-sixth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Monadic datalog over finite structures with bounded treewidth
Proceedings of the twenty-sixth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Polynomial time fragments of XPath with variables
Proceedings of the twenty-sixth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
VLDB '03 Proceedings of the 29th international conference on Very large data bases - Volume 29
Theoretical Computer Science
Expressiveness and complexity of XML publishing transducers
ACM Transactions on Database Systems (TODS)
ACM Computing Surveys (CSUR)
Reasoning about XML with Temporal Logics and Automata
LPAR '08 Proceedings of the 15th International Conference on Logic for Programming, Artificial Intelligence, and Reasoning
Two-variable logic on data trees and XML reasoning
Journal of the ACM (JACM)
The finite model theory toolbox of a database theoretician
Proceedings of the twenty-eighth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Running tree automata on probabilistic XML
Proceedings of the twenty-eighth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Incorporating constraints in probabilistic XML
ACM Transactions on Database Systems (TODS)
Xml publishing: bridging theory and practice
DBPL'07 Proceedings of the 11th international conference on Database programming languages
Tree automata over infinite alphabets
Pillars of computer science
Monadic datalog over finite structures of bounded treewidth
ACM Transactions on Computational Logic (TOCL)
XPath whole query optimization
Proceedings of the VLDB Endowment
Query-preserving watermarking of relational databases and Xml documents
ACM Transactions on Database Systems (TODS)
Efficient reasoning about data trees via integer linear programming
Proceedings of the 14th International Conference on Database Theory
The model checking problem for prefix classes of second-order logic: a survey
Fields of logic and computation
FroCoS'11 Proceedings of the 8th international conference on Frontiers of combining systems
Combining temporal logics for querying XML documents
ICDT'07 Proceedings of the 11th international conference on Database Theory
Automata for positive core XPath queries on compressed documents
LPAR'06 Proceedings of the 13th international conference on Logic for Programming, Artificial Intelligence, and Reasoning
N-ary queries by tree automata
DBPL'05 Proceedings of the 10th international conference on Database Programming Languages
Minimizing tree automata for unranked trees
DBPL'05 Proceedings of the 10th international conference on Database Programming Languages
Matching with regular constraints
LPAR'05 Proceedings of the 12th international conference on Logic for Programming, Artificial Intelligence, and Reasoning
Logics for unranked trees: an overview
ICALP'05 Proceedings of the 32nd international conference on Automata, Languages and Programming
A formal comparison of visual web wrapper generators
SOFSEM'06 Proceedings of the 32nd conference on Current Trends in Theory and Practice of Computer Science
Deterministic automata on unranked trees
FCT'05 Proceedings of the 15th international conference on Fundamentals of Computation Theory
Automata and logics for unranked and unordered trees
RTA'05 Proceedings of the 16th international conference on Term Rewriting and Applications
A logic-based approach to cache answerability for XPath queries
XSym'06 Proceedings of the 4th international conference on Database and XML Technologies
Datalog relaunched: simulation unification and value invention
Datalog'10 Proceedings of the First international conference on Datalog Reloaded
Foundations of XML based on logic and automata: a snapshot
FoIKS'12 Proceedings of the 7th international conference on Foundations of Information and Knowledge Systems
Deciding twig-definability of node selecting tree automata
Proceedings of the 15th International Conference on Database Theory
Efficient reasoning about data trees via integer linear programming
ACM Transactions on Database Systems (TODS)
ICALP'12 Proceedings of the 39th international colloquium conference on Automata, Languages, and Programming - Volume Part II
Regular languages of nested words: fixed points, automata, and synchronization
ICALP'07 Proceedings of the 34th international conference on Automata, Languages and Programming
Recursive queries on trees and data trees
Proceedings of the 16th International Conference on Database Theory
Spanners: a formal framework for information extraction
Proceedings of the 32nd symposium on Principles of database systems
Hi-index | 5.23 |
A main task in document transformation and information retrieval is locating subtrees satisfying some pattern. Therefore, unary queries, i.e., queries that map a tree to a set of its nodes, play an important role in the context of structured document databases. The motivation of this work is to understand how the natural and well-studied computation model of tree automata can be used to compute such queries. We define a query automaton (QA) as a deterministic two-way finite automaton over trees that has the ability to select nodes depending on the state and the label at those nodes. We study QAs over ranked as well as over unranked trees. Unranked trees differ from ranked ones in that there is no bound on the number of children of nodes. We characterize the expressiveness of the different formalisms as the unary queries definable in monadic second-order logic (MSO). In contrast to the ranked case, special stay transitions had to be added to QAs over unranked trees to capture MSO. We establish the complexity of the non-emptiness, containment, and equivalence of QAs to be complete for EXPTIME.