PROXIMAL NODES - A MODEL TO QUERY DOCUMENT DATABASES BY CONTENT AND STRUCTURE

A model to query document databases by both their content and structur e is presented. The goal is to obtain a query language that is express ive in practice while being efficiently implementable, features not pr esent at the same time in previous work. The key ideas of the model ar e a set-oriented query language based on operations on nearby structur e elements of one or more hierarchies, together with content and struc tural indexing and bottom-up evaluation. The model is evaluated in reg ard to expressiveness and efficiency, showing that it provides a good trade-off between both goals. Finally, it is shown bow to include in t he model other media different from text.