The NEXT Framework for Logical Xquery Optimization Alin Deutsch, Yannis Papakonstantinou, and Yu Xu   View Paper (PDF)   Return to RESEARCH SESSION 4: XML (I) Abstract Classical logical optimization techniquesrely on a logical semantics of the query language. The adaptation of these techniques to XQuery is precluded by its definition as a functional language with operational semantics. We introduce Nested XML Tableaux which enable a logical foundation for XQuery semantics and provide the logical plan optimization framework of our XQuery processor. As a proof of concept, we develop and evaluate a minimization algorithm for removing redundant navigation within and across nested subqueries. The rich XQuery features create key challenges that fundamentally extend the prior work on the problems of minimizing conjunctive and tree pattern queries. ©2005 Association for Computing Machinery