Know your Limits: Enhanced XML Modeling with Cardinality Constraints
نویسندگان
چکیده
XML Schema supports the specification of occurrence constraints by declaring values for its min/maxOccurs attributes. These constraints are structural in the sense that they restrict the cardinality of children elements independently of the data that is present in their subtrees. Thus, occurrence constraints do not address any data semantics and are therefore only of limited interest to data modelling. In this tutorial we first survey the benefits of introducing semantic cardinality constraints into the framework of XML modeling languages: enhanced modeling capabilities, increased levels of data consistency and integrity, additional techniques for XML query optimization and query rewriting, prediction of the number of XML query answers, updates and encryptions. Secondly, we survey different techniques of representing many-to-many relationship types within XML. In particular, we focus on the preservation of key, foreign key and participation constraints.
منابع مشابه
Cardinality Constraints for XML: Challenging the Trade-off between Expressiveness and Tractability 2. IDENTIFICATION Contact Principal Investigator Name (with title): Associate Professor Sebastian Link Full Address: School of Information Management
Describe in up to 200 words the nature of your proposed research in plain English for a general audience. This summary should be able to be used for publicity purposes if the proposal is offered funding. The eXtensible Markup Language (XML) has evolved to be the " lingua franca " for data integration and data exchange on the Internet and elsewhere. This development has led to a dramatic increas...
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