Group Nearest Neighbor Queries

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 1i3. 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.

• Type: Conference
• Year: 2004
• Where: ICDE
• Authors: Dimitris Papadias, Qiongmao Shen, Yufei Tao, Kyriakos Mouratidis
• Keywords: Database, Group Nearest Neighbor, Group Nearest Neighbors, ICDE 2004, Non-indexed Query Points