eXrQuy: Order Indifference in XQuery
Publication Details
Title
eXrQuy: Order Indifference in XQuery
Authors
Torsten Grust, Jan Rittinger, and Jens Teubner
Published
Proceedings 23rd Int'l Conference on Data Engineering (ICDE), Istanbul, Turkey, April 2007.
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Abstract
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)