Pathfinder: XQuery Off the Relational Shelf

The Pathfinder project makes inventive use of relational database technology — originally developed to process data of strictly tabular shape — to construct efficient database — supported XML and XQuery processors. Pathfinder targets database engines that implement a set-oriented mode of query execution: many off-the-shelf traditional database systems make for suitable XQuery runtime environments, but a number of off-beat storage back-ends fit that bill as well. While Pathfinder has been developed with a close eye on the XQuery semantics, some of the techniques that we will review here will be generally useful to evaluate XQuery-style iterative languages on database back-ends.