The structure of typed programming languages
The structure of typed programming languages
MSL — a model for W3C XML schema
Proceedings of the 10th international conference on World Wide Web
Minimization of tree pattern queries
SIGMOD '01 Proceedings of the 2001 ACM SIGMOD international conference on Management of data
Efficient algorithms for minimizing tree pattern queries
Proceedings of the 2002 ACM SIGMOD international conference on Management of data
EDBT '02 Proceedings of the Worshops XMLDM, MDDE, and YRWS on XML-Based Data Management and Multimedia Engineering-Revised Papers
Secure XML querying with security views
SIGMOD '04 Proceedings of the 2004 ACM SIGMOD international conference on Management of data
Frontiers of tractability for typechecking simple XML transformations
PODS '04 Proceedings of the twenty-third ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
XPath satisfiability in the presence of DTDs
Proceedings of the twenty-fourth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Query translation from XPATH to SQL in the presence of recursive DTDs
VLDB '05 Proceedings of the 31st international conference on Very large data bases
XPath Query Simplification with regard to the Elimination of Intersect and Except Operators
ICDEW '06 Proceedings of the 22nd International Conference on Data Engineering Workshops
On testing satisfiability of tree pattern queries
VLDB '04 Proceedings of the Thirtieth international conference on Very large data bases - Volume 30
Taming XPath queries by minimizing wildcard steps
VLDB '04 Proceedings of the Thirtieth international conference on Very large data bases - Volume 30
A prototype of a schema-based XPath satisfiability tester
DEXA'06 Proceedings of the 17th international conference on Database and Expert Systems Applications
Selectivity-sensitive shared evaluation of multiple continuous XPath queries over XML streams
Information Sciences: an International Journal
Knowledge and Information Systems
On the expressiveness of generalization rules for XPath query relaxation
Proceedings of the Fourteenth International Database Engineering & Applications Symposium
A utilization of schema constraints to transform predicates in XPath query
DEXA'10 Proceedings of the 21st international conference on Database and expert systems applications: Part I
Semantic transformation approach with schema constraints for XPath query axes
WISE'10 Proceedings of the 11th international conference on Web information systems engineering
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Writing correct and precise XPath queries needs much effort from users: the user must be familiar with the complex structure of the queried XML documents and has to compose queries, which must be syntactically and semantically correct and precise. Incorrect queries select no data and thus lead to highly inefficient processing of queries. Unprecise queries might select more data than what the user really wants and thus might lead to unnecessarily high processing and transportation costs. Therefore, we propose a schema-based approach to the satisfiability test and to the refinement of users' XPath queries. Our schema-based approach checks whether or not an XPath query conforms to the constraints given in the schema, rewrites and refines the XPath query according to the information of the schema. If an XPath query does not conform to the constraints given in the schema, its results will be every time an empty node set, which is a hint for semantic errors in the XPath query. Our rewriting approach for XPath queries replaces wildcards with specific node tests, replaces recursive axes with non-recursive axes, eliminates reverse axes, and redundant location steps. Thus, our rewriting approach generates a query, which contains more information, and can be more easily refined by the user in comparison to the original query. Our performance analysis shows the optimization potential of avoiding the evaluation of unsatisfiable XPath queries and of processing rewritten and refined XPath queries.