Lore: A Database Management System for XML

Jennifer Widom
Database Group Faculty


Over the past several years database researchers have explored issues in managing schema-less "semistructured" data: data that may be irregular or incomplete, and whose structure may evolve rapidly and unpredictably. The Lore system at Stanford, under research and development for the past 4 years, is a full-featured DBMS designed specifically for semistructured data. Fortuitously, Lore's original data model, called the Object Exchange Model (OEM), is very similar to W3C's new eXtensible Markup Language (XML), and we have just completed migrating Lore to full XML compliance.

I will provide an overview of the Lore system and will briefly highlight some of its more challenging and novel aspects: Lore's expressive OQL-based query language, indexing capabilities, cost-based query optimizer, dynamic structural summaries, and proximity search capabilities. The talk will be followed by a demonstration of Lore's stand-alone capabilities, and (time permitting) a demonstration of Lore serving as an XML engine behind a Microsoft prepackaged XML demo.

To find out more about Lore or experiment with the online demos please visit http://www-db.stanford.edu/lore

The talk presents joint work with Roy Goldman and Jason McHugh.


Jennifer Widom received her Bachelors degree from the Indiana University School of Music in 1982 and her Ph.D. from Cornell University in 1987. From 1987-88 she was a Visiting Assistant Professor in the Computer Science Department at Cornell. She spent five years as a Research Staff Member at the IBM Almaden Research Center before joining the Stanford faculty in 1993.