Here at the IIT Information Retrieval Lab, we have developed technology for mapping hierarchical semi-structured data of any schema onto existing relational platforms in such a way that it can still be queried by standard XML query languages.

This is done by creating a fixed set of relations that contain a record for each distinct path in the hierarchy of an XML document.  We are then able to perform automated query translation from a standard XML query language, XML-QL, to standard SQL, and leave the job of query optimization to the well-proven relational engine.

This work is currently in production, having been deployed at a major corporation.   At present, it has been shown to scale to 80 million rows in relational systems.

Please see the author's information page for links to further information and technical papers on this system.

Last updated: May 01, 2002.