Group nearest neighbor queries

Abstract

Given two sets of points P and Q, a group nearest neighbor (GNN) query retrieves the point(s) of P with the smallest sum of distances to all points in Q. Consider, for instance, three users at locations q1, q2 and q3 that want to find a meeting point (e.g., a restaurant); the corresponding query returns the data point p that minimizes the sum of Euclidean distances \pqi\ for 1≤i≤3. Assuming that Q fits in memory and P is indexed by an R-tree, we propose several algorithms for finding the group nearest neighbors efficiently. As a second step, we extend our techniques for situations where Q cannot fit in memory, covering both indexed and non-indexed query points. An experimental evaluation identifies the best alternative based on the data and query properties.

Date of Award	2003
Original language	English
Awarding Institution	The Hong Kong University of Science and Technology