Font Size: a A A

Research Of Encoding Scheme For XML Document

Posted on:2012-05-26Degree:MasterType:Thesis
Country:ChinaCandidate:N NiuFull Text:PDF
GTID:2218330338462896Subject:Computer software and theory
Abstract/Summary:PDF Full Text Request
With the development of XML in the Internet, especially the development of Web techniques and its applications, XML, Extensible Markup Language, has actually become the data transmission standard in the Internet. XML document is storing based on semi-structured data, it has shown its advantage in storing data after only a few years.Especially, these years XML is applied in many study fields, and now it becomes the standard of the data transmission, so how to effectively store and query these data is a hot topic of research in academia now. And as one of the most important issues for XML data processing, query technologies have become the focus. An XML document can be viewed as a tree whose nodes are the document items and whose edges correspond to relationship among data items. Query solving of the Native XML database as follows:one is data guides algorithm based on index; one is algorithm based on encoding schemes; another is sequence matching algorithm based on sequential identification. Typical queries over XML documents amount to finding nodes with particular tags having certain ancestor relationship between them. If the XML document based on label scheme, look only at the labels to determine the relationship between two nodes without access to the actual document.To effectively support structural query, various encoding schemes have been proposed. In this paper, we analyze the disadvantages of the current XML encoding schemes, take advantage of the interval-based label and prefix label and provide a new XML encoding scheme-MBL. And then design a storing scheme to store Native XML data. When insert nodes to the XML tree, the physical block is limit to store the subtree. In order to solve this problem, we give subtree split algorithm. Next we considering how to identify the ancestor-descendant relationship, the parent-child relationship and so on in constant time based on this encoding scheme. What's more, the scheme also shows how many levels between the two given nodes (distance).To further enhance the efficiency of documents' searching, we improve the structural join algorithm based on MBL encoding scheme. At last, the paper conducts some performance tests, on the one hand to validate the correctness and validity of MBL scheme, on the other hand to verify the good performance of the storing scheme and the structural join algorithm based on MBL encoding scheme.
Keywords/Search Tags:XML, XML tree, Encoding scheme, Storing scheme, Index scheme, Structural join
PDF Full Text Request
Related items