“…Given the established bounds on the extra cost and the impossibility result, a large number of declustering techniques have been proposed to achieve performance close to the bounds either on the average case [5], [12], [13], [14], [16], [22], [24], [25], [29], [31], [36], [37] or, in the worst case, [3], [6], [7], [9], [41]. Although initial approaches in the literature were originally for relational databases or Cartesian product files, recent techniques focus more on spatial data declustering.…”