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As information on the world wide web continues to proliferate at an astounding rate, the extensible markup language (XML) has been emerging as a standard format for data representation on the web. In many applications, specific document type definitions (DTDs) are designed to enforce a semantically agreed-upon structure of the XML documents for management.(More)
We study XML stream-specific schema-based optimization. We assume a widely-adopted automata-based execution model for XQuery evaluation. Criteria are established regarding what schema constraints are useful to a particular query. How to apply multiple optimization techniques on an XQuery is then addressed. Finally we present how to correctly and efficiently(More)
When updating a valid XML document, an efficient yet light-weight mechanism is needed to determine if the up-date would invalidate the document. Towards this goal, we developed a framework called SAXE, we first analyzed the constraints expressed in XML schema specifications and establish constraint rules that must be observed for an XML document to conform(More)
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This paper describes cost-based query transformation in Oracle relational database system, which is a novel phase in query optimization. It discusses a suite of heuristic- and cost-based transformations performed by Oracle. It presents the framework for cost-based query transformation, the need for such a framework, possible interactions among some of the(More)
XML stream applications bring the challenge of efficientlyprocessing queries on sequentially accessible token-based data.While the automata model is naturally suited for pattern matchingon tokenized XML streams, the algebraic model in contrast is awell-established technique for set-oriented processing ofself-contained tuples. However, neither automata nor(More)