XML Data Stream XPath Query Model

XML stream data processing systems typically run on Web,the users may increase to hundreds of thousands,millions.And users' queries are usually expressed in XPath language.The system determines whether the XML data stream to satisfy a special user's demand according to the XPath description when XML data inflows by network speed.If met,it would trigger the application to take some actions,such as feeding back related documents to users.A user may submit a number of queries. Therefore queries' quantity is very huge.Thus,for XML data stream query research,a key challenge is how to effectively deal with a large number of inquiries from users and promptly return the results to the user.This article in view of the XML data stream's characteristic,on the foundation of the summary of the present XML data stream XPath query processing method,in view of the many application in indefinite data environment's condition,proposed a new query model GBRender (Group-Based Rendering of XML Data Stream XPath Query Model),that is,group-based rendering of XML data stream XPath query model,as well as one kind of predicate processing model which adapts this model. The main contents are as follows:1.It proposed a new XML data stream XPath query model named GBRender:Group-Based Rendering XML data stream XPath Query Model,and the group rendering concept,the related definition,as well as the model structural feature and the processing model have been given.2.It proposed one kind of XPath predicate processing initiative computation model,on the foundation of thorough analysis of the predicate expression characteristics,it has given the initiative computation model's basic idea,the model structure and the processing algorithm.3.It has given the single branch query processing algorithm under GBRender model,as well as the structure of using the initiative computation model to process complex predicates,and proves its efficiency.4.The group render query model's low dependence and validity has been proved through experiments.