16. The method of claim 14 , wherein said associating step includes aggregating derived values of a plurality of nodes satisfying a portion of the query.
16. The method of claim 14 , wherein said associating step includes aggregating derived values of a plurality of nodes satisfying a portion of the query. 22. The method of claim 16 , wherein said associating step includes marshalling arguments from aggregated derived values at aggregation boundaries for input to the function.