  It is widely acknowledged that good object clustering is critical to the
performance of object-oriented databases. However, object clustering always
involves some kind of overhead for the system. The aim of this paper is to
propose a modelling methodology in order to evaluate the performances of
different clustering policies. This methodology has been used to compare the
performances of three clustering algorithms found in the literature (Cactis, CK
and ORION) that we considered representative of the current research in the
field of object clustering. The actual performance evaluation was performed
using simulation. Simulation experiments we performed showed that the Cactis
algorithm is better than the ORION algorithm and that the CK algorithm totally
outperforms both other algorithms in terms of response time and clustering
overhead.
