Multiple schema based XML indexing

With the prevalence of XML, XML query processing becomes a hot topic. Most techniques available now are generic to XML documents that are completely schema-less or adhere to only one DTD, In this paper, we propose MXI, a XML indexing method that supports efficient path query of XML documents in both single- and multi-DTD settings. The main feature of MXI is to take advantage of information embedded in DTD for speeding up the process of XML path query. A path expression with one predicate restriction needs only zero or two structural join operations per XML document. For a path expression that is not complying with any paths in XML documents to be searched, MXI can give a judgment of no answer in much shorter time than those of indexing methods available now. We detail our techniques and key algorithms and demonstrate the superiority of MXI in path query efficiency over Lore, XISS and SphinX via experimental results.