Practical space-efficient data structures for high-dimensional orthogonal range searching

Abstract

We consider the orthogonal range search problem: given a point set P in d-dimensional space and an orthogonal query region Q, return some information on P ∩ Q. We focus on the counting query to count the number of points of P contained in Q, and the reporting query to enumerate all points of P in Q. For 2-dimensional case, Bose et al. proposed a space-efficient data structure supporting the counting query in O(lg n/lg lg n) time and the reporting query in O(k lg n/lg lg n) time, where n=|P| and k=|P ∩ Q|. For high-dimensional cases, the KDW-tree [Okajima, Maruyama, ALENEX 2015] and the data structure of [Ishiyama, Sadakane, DCC 2017] have been proposed. These are however not efficient for very large d. This paper proposes practical space-efficient data structures for the problem. They run fast when the number of dimensions d′ used in queries is smaller than the data dimension d. This kind of queries are typical in database queries.