Table 2.

Characteristic of the queries used in the experiments (default values are represented in bold)

Queries	Description
k-NN queries	Find the nearest k points to a query point (k = 10, 100, 1000, 100,000)
Circle queries	Find all the points within a circle having a radius r around a query point (r = 10KM, 100KM, 1000KM)
Bounding box queries	Find all the points within a bounding box (10KM $\times$ 10KM, 100KM $\times$ 100KM, 1000KM $\times$ 1000KM)
Distance join queries	Find all the pairs from two spatial data sets A and B where the distance of each pair is less or equal than a threshold (0.1KM, 1KM, 10KM). Here, A is a variable data set and B is a fixed data set consisting of 100 points