Query containment is a fundamental algorithmic problem in database query processing and optimization. Under set semantics, the query-containment problem for conjunctive queries ha...
Traditionally, data that has both linear and hierarchical structure, such as annotated linguistic data, is modeled using ordered trees and queried using tree automata. In this pap...
Many users and applications require the integration of semi-structured data from autonomous, heterogeneous Web sources. Over the last years mediator systems have emerged that use d...
Path expressions are the principal means of locating data in a hierarchical model. But path expressions are brittle because they often depend on the structure of data and break if...
The problem of data integration (query decomposition, data fragmentation) has been widely studied in literature, but the inherent hierarchical nature of XML data presents problems...