An XML Query Algorithm with Multi-modal Index Structure

This paper proposes a multi-modal index structure to retrieve XML data based on the idea of the numbering scheme,the path index and name extension.The index structure not only determines ancestor/descendant relationships by supporting the structural join algorithm but also determines parent/child relationships by the path join algorithm based on name extension,and meanwhile effectively deals with branching query including holding relationships.Then,an extension join algorithm based on the index structure is given so that n/2-1 times at most for joining among extensions are needed for Xpath absolute path queries with n query nodes.Experimental results show that the new index structure can effectively enhance the query performance for XML data.