Study On The XML Indexing Technique Based On Schema

XML has become the standard and as a flexsible medium of data representation and exchange on the web.Meanwhile,with the rapid development of Internet,the structure of XML documents and query demand of users are becoming more complicated.In order to retrieve the results to path efficiently,people pay many attention to XML indexing.At present, there are many techniques on XML data query,but most of these techniques are not use their pattern information.The dissertation brings forword two XML indexing methods which based on Schema while using XML pattern information to locate nodes.The major tasks include:(1) In a document traversal process,completed a series of operations,such as the distribution of location information,to solve the absolute path and further merge these paths,while using much less construction time.(2) In a document traversal process,completed a series of operations,such as the distribution of tag information,carries corresponding schema structural information and merge nodes clustered-cell,while using much less construction time.(3) Improves query speed by reduceing the amount of nodes that have to search,while using Path-Match algorithm.(4) Avoid the trival multiple branching query processing in CAPI and provide nested query function,while using Path-Segmentation algorithm.(5) All nodes will be stored with the same layer, grouped according to the node source path information to improve the retrieval speed of nodes.Compared with the TwigStack,Twig2Stack and TJFast indexes,our experimental results demonstrate that SAPI and SOPI perform more efficiently in terms of invalid query, branching query,nested query and take smaller I/O cost,while using much less construction time.