Jump label

Service navigation

Main navigation

You are here:

Main content

eXrQuy: Order Indifference in XQuery

Publication Details


eXrQuy: Order Indifference in XQuery


Torsten Grust, Jan Rittinger, and Jens Teubner


Proceedings 23rd Int'l Conference on Data Engineering (ICDE), Istanbul, Turkey, April 2007.


paper (PDF)


There are more spots than immediately obvious in XQuery expressions where order is immaterial for evaluation―this affects most notably, but not exclusively, expressions in the scope of unordered { } and the argument of fn:unordered(). Clearly, performance gains are lurking behind such expression contexts but the prevalent impact of order on the XQuery semantics reaches deep into any compliant XQuery processor, making it non-trivial to set this potential free. Here, we describe how the relational XQuery compiler Pathfinder uniformly exploits such order indifference in a purely algebraic fashion: Pathfinder-emitted plans faithfully implement the required XQuery order semantics but (locally) ignore order wherever this is admitted.

Publication Log

October 2006

camera-ready for ICDE 2007

June 2006

submission to ICDE 2007 (accepted as full paper)

  • reviews (results: weak accept, strong accept, accept)
March 2006

submission to VLDB 2006 (rejected)

  • reviews (results: weak reject, accept, reject)

Sub content


Prof. Dr. Jens Teubner
Tel.: 0231 755-6481