On the Expressive Power of Node Construction in XQuery Wim Le Page, Jan Hidders, Philippe Michiels, Jan Paredaens, and Roel Vercammen   View Paper (PDF)   Return to Paper Session 5: XML Abstract . Hence, for each query that uses the nested relational model and that, with a flat table as input always has a flat table as output, there exists an equivalent flat query that only uses the flat relational model. In analogy, we study a related flat-flat problem for XQuery: for each expression containing operations that construct new nodes and whose XML result contains only original nodes, there exists an equivalent "flat" expression in XQuery that does not construct new nodes. ©2006 Association for Computing Machinery