View usability and safety for the answering of top-k queries via materialized views

In this paper, we investigate the problem of answering top-k queries via materialized views. We provide theoretical guarantees for the adequacy of a view to answer a top-k query, along with algorithmic techniques to compute the query via a view when this is possible. We explore the problem of answering a query via a combination of more than one view and show that it is impossible to improve our theoretical guarantees for the answering of a query via a combination of views. Finally, we experimentally assess our approach for its effectiveness and efficiency.