Experimental Evaluation of Rank-Aware Plans. A ranking query retrieves the top few results of an SPJ query based on a scoring function. As an example, consider a sample database that stores information about visitors to a specific area. Assume that a visitor wants to plan out a short stay that includes a hotel, a restaurant, and an event. The following query will retrieve the top-10 combinations of such results, based on the rating of the hotel, the rating of the restaurant, and the type of the event:
SELECT r.name, h.name, e.title
FROM Restaurant r, Hotel h, Event e
WHERE r.city = h.city AND h.city = e.city
RANK BY 0.4 * r.rating + 0.4 * h.rating + 0.2 * contains(e.title,"Music")
LIMIT 10
The topic of this project is to evaluate experimentally different physical plans for answering this type of queries. In particular, the project will consider plans that use a specific join algorithm, termed HRJN*. There are theoretical results on the optimality of this algorithm for the specific type of queries. The goal of the project is to corroborate the theoretical results with an experimental evaluation.