Study On Techniques Of Metadata Management And Indexing In NEXT System

With the rapid development of Internet, XML is emerging as a de facto standard for information representation and data exchange over the Web. Therefore, it presents a new challenge to manage XML data through databases. As semi-structured data, XML can be represented as a tree-structured model with data contents and structural relationships among them.Unlike in traditional databases, queries on XML documents aim at not only element contents but also structural relationships between tagged elements. Various techniques about XML data storage, indexing and query processing have been developed recently, among which, Native XML data management is an attractive technique for its storage, indexing, query processing and optimization techniques are specially designed for XML data.In this thesis, XML data management, especially the management of metadata, are studied based on Native XML data management technology. On the base of an XML data management prototype system, named NEXT, metadata management module is implemented to effectively manage the numerous XML data and XML Schema, providing a platform of XML loader, XML storage and XML Schema manager. Indices for metadata management are also discussed based on DOM, such as XML Value Index, XML Reference Index and XML Path Index, which support all the components of Metadata Management, including NxNameManager, NxNamespace-Manager and NxSchemaManager.