Since XML (eXtensible Markup Language) (Bray, Paoli, Sperberg-McQueen, Maler & Yergeau, 2004) emerged as a standard for information representation and exchange, storing, indexing, and querying, XML documents have become major issues in database research. Query processing and optimization are very important in this context, and indices are data structures that help enhance performances substantially. Though XML indexing concepts are mainly inherited from relational databases, XML indices bear numerous specificities. The aim of this chapter is to present an overview of state-of-the-art XML indices and to discuss the main issues, trade-offs, and future trends in XML indexing. Furthermore, since XML is gaining importance for representing business data for analytics (Beyer, Chamberlin, Colby, Özcan, Pirahesh & Xu, 2005), we also present an index we developed specifically for XML data warehouses.
XML Indexing Techniques for Handling Large Amounts of Data