An XML-IR-DB Sandwich: Is it Better with an Algebra in Between
Vojkan Mihajlović, Djoerd Hiemstra, Henk Ernst Blok, Peter M. G. Apers, Ricardo Baeza-Yates, Yoelle Maarek, Thomas Roelleke, Arjen P. de Vries · University of Twente Research Information · 2004
In this paper we address the problem of immediate translation of XPath+IR queries to relational database expressions and exert the benefits of using an intermediate algebra. Adding an intermediate algebra on the logical level of a database enables a level of abstraction from both query languages for IR in XML documents and the underlying relational storage. This paper proposes a region algebra that can be extended to support ranking operators in an elegant way while staying algebraic. Furthermore, region algebra operator properties provide a firm ground for query rewriting and optimization. 1.