Spatial databases have been increasingly and widely used in recent years. T
he R-tree proposed by Guttman is probably the most popular dynamic index st
ructure for efficiently retrieving objects from a spatial database accordin
g to their spatial locations. However, experiments show that only about 70%
storage utilization can be achieved in Guttman's R-tree and its variants.
In this paper, we propose a compact R-tree structure which can achieve almo
st 100% storage utilization. Our experiments also show that the search perf
ormance of compact R-trees is very competitive as compared to Guttman's R-t
rees. In addition, the overhead cost of building a compact R-tree is much l
ower than that of a Guttman's R-tree because the frequency of node splittin
g is reduced significantly. (C) 2001 Elsevier Science Inc. All rights reser
ved.