Research On Tiwg Pattern Matching Of XML Based On Index

Now Internet development has completely permeated all aspects of the work of people's lives. As a semi-structured XML language has become one of the most important data carrier, in Web services, e-commerce, digital libraries, and many other network-related applications have become the de facto standard to describe data. In recent years, how the effective management of XML data and query, and how user data from the flood of XML to extract the information they need to be more and more of today's domestic and foreign scholars. Therefore, many of the XML data query algorithm came into being, making XML data query XML data management to become a hot spot.From the perspective of XML database systems, a thorough analysis of the existing XML document tree twig query technology and the lack of face. Through research and improve the coding scheme to organize XML documents quickly and in accordance with the characteristics of XML queries, we propose a new index REI, which is a data structure has a simple and rigorous logical structure of the index of technology. Meanwhile, in order to further improve the efficiency of query, the index of this interval also used to improve the coding scheme to organize and reference XML data.Another research focus of this article is to queries of XML documents. XML queries can be expressed as a tree path expression to describe the query request an independent inquiry. In terms of these two path queries, XML queries can be expressed as a twig pattern query, all found in the database in XML twig pattern emerging XML query processing is the core of the current operation. Based on this idea, we propose a new index-based query model. Drawing on the advantages of existing related algorithms, abandoned on the basis of which many shortcomings, an improved range of code between nodes quickly determine ancestor-descendant or parent-child relationship, and use the index REI, further design a new efficient algorithms RE-TWIG, the algorithm can effectively reduce the query complexity and redundancy, to quickly get target node.The main work and innovations in the following areas:1,Describes the XML document node mainstream coding schemes, describes the decomposition method of twig path index and query. Query algorithm based on the characteristics of this article, an improved range of encoding, in order to determine quickly the logic of a direct relationship between nodes.2,In this paper, an index REI to store XML documents. No matter what form the XML index is, the actual design and implementation must take into consideration the basic features of XML queries, the preservation of the structural relations and fast calculation based on structural information structural relationship between nodes of these two factors, which in fact is to ask the relevant Efficient processing of XML technology to meet the query request.3,On the basis of the previous two o'clock, proposed, designed and implemented based on improved range of encoding and REI index twig pattern query algorithm. The algorithm including the target node selection and twig query pattern matching in two parts. Gave a performance by experimental verification.In order to facilitate the understanding of the above study sites, the paper with an example XML document tree based on the example of a general query instance, shows in detail the entire process of running the algorithm.This article on how to build effective indexing and querying XML database technology aspects of the exploratory study and hope to solve the problem of providing an effective ideas and methods. This foundation is also the subject of the field of XML query technology used widely, not only how to better encode the XML document tree and the index is designed to provide ideas and methods, but also for query-based index of the twig study provides some help. This makes this exploratory research has both theoretical research value, but also has great application value and practical significance.