On Maximal Contained Rewriting of Tree Pattern Queries Using Views

Abstract

The problem of rewriting tree pattern queries using views has attracted much attention in recent years. Previous works have proposed algorithms for finding the maximal contained rewriting using views when the query and the view are limited to some special cases, e.g., tree patterns not having the wildcard *. In the general case, i.e, when both //-edges and * are present, the previous methods may fail to find the maximal contained rewriting. In this paper, we propose a method to find the maximal contained rewriting for the general case, as well as an extension of the previous method to more special cases.