Metadata Storing And Retrieval-Design And Implementation Of MSR System

With the popularity of the World Wide Web and information technology, the knowledge people have appears a trend of explosive growth, the information resources accumulated in each application field are being increased rapidly. These information resources include audio, video, web pages, text, and other formats, which have various forms, described in different ways, lack of standards, all the above bring many challenges to the exchange of information and the management of information resources . Metadata is the mechanism which can solve these problems effectively.However, presently, the metadata structures and their storage and presentation are diverse, which served for various on-line digital resources. Different metadata structure has its own advantage and is playing an important and unique role in different field, so in the short term, they can not replace each other. Therefore, to design a metadata storage retrieval system which can adapt to different structure of the metadata is of great practical significance and theoretical significance.On the basis of participating Shanghai's Scientific and Technological Project "The Research On Knowledge-Sharing System for the World Expo Based On the Metadata Management", this article take the design for building a Metadata Storage Retrieval System which can adapt to different metadata structure as the starting point, based on Web Service technology, do some research on the metadata storage and retrieval from system design to specific metadata applications , and then design and implement a prototype system.The author's main work and achievements are:First of all, in the context of the needs analyzed with the project, this article brings forward the architecture and level of Metadata Storage Retrieval System(MSR),and later practice proves that the architecture and level mechanism has good adaptability and application scalability.Secondly, brings forward the method to store and retrieve the XML files based on XOM and ORM tool, which realizes to build the metadata storage management system that do not rely on the XML document's specific structure. And also, with the use of HQL and the structure information map, the article realize the isolation between metadata application system and metadata specific structure, which make MSR system can adapt to metadata of different structure and has good portability.Thirdly, based on compiler technology, from the perspective of Xquery's grammar, use the HQL to simulate Xquery language semantics, and use specific procedure combined with the XOM tool to build the inquiry results, and set up Xquery conversion engine eventually. Then, fit Xquery conversion engine together with the SOAP-based metadata remote management platform, so that make the outside world easier and uniform to query and use of MSR system, and facilitate the outside world to do the expansion and reuse of functions.Finally, design and realize the metadata retrieval application. With the classification of the query statement's filtering and group conditions, utilization of the relation map between type and its comparison operator, implementation of the type matrix matching strategy, all the above make the search more flexible and diversified. Aiming at the topic search which locates resources, with combining the topic search based on metadata and the ontology of knowledge area, brings forward the algorithm about theme related weight comparison, these provide a useful reference and realization for the intelligent knowledge-based topic search.This paper is supported by Shanghai's Scientific and Technological Project -"Action Plan For Climbing" International Cooperation in 2006 "The Research On Knowledge-Sharing System for the World Expo Based On the Metadata Management".