A path index for efficient XML path expression processing

XML is a de fact standard for data representation and exchange on the Internet, therefore storing and querying XML repositories has become an important issue. Several XML query languages are based on the use path expressions containing optional wildcards. This poses a new problem, given that traditional query processing approaches have been proven not to be efficient in this case. We proposed a new path index to efficiently process path expressionswith wildcards on XML data. Extensive evaluation confirms better performance with respect to other techniques proposed in the literature. An extension of the proposed technique to deal with the content of XML documents in addition to their structure is also discussed.