Schema-conscious filtering of XML documents

摘要

In a publish-subscribe system based on filtering of XML documents, subscribers specify their interests with profiles expressed in the XPath language. The system processes a stream of XML documents and delivers to subscribers a notification or content of documents that match the profiles. For filtering with profiles expressed as linear XPath queries, automaton-based approaches exist where the intractable size growth of a preconstructed deterministic finite automaton is avoided by using a nondeterministic automaton. In this article we examine how these general approaches, which do not assume the existence of any specific schema or document type definition (DTD), might benefit from the knowledge that all the XML documents to be filtered obey a given DTD.