Information Technology Convergence, International Symposium on (2007)
Nov. 23, 2007 to Nov. 24, 2007
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/ISITC.2007.60
XQuery is a functional query language for XML in which generally no order for the evaluation of sub-expressions is assumed. However, there are in fact several sources of side effects, including a subtle one caused by element construct- ing in the current version, data manipulation outside of the language by user-code via API, and possible future update extensions. They prevent an implementation from optimiza- tion by reordering the execution or parallel processing. In this paper, two approaches are proposed to tackle these ob- stacles. One is to reconsider the treatment of the store, and the other is to introduce a way to identify the portions where the updates actually take place. We believe these proposi- tions will help the implementations perform safer optimiza- tions. Keywords XQuery, data model, store, update, DOM, side-effects, element construction, functional language, for- mal semantics
H. Kato, M. Yoshikawa and S. Hidaka, "A More Optimizer-Friendly Treatment of XQuery Store in the Presence of Side-Effects," Information Technology Convergence, International Symposium on(ISITC), Jeonju, Korea, 2007, pp. 32-36.