Hot-spot based composition algorithm

A composition requires three operations: join, project, and duplicate elimination. A hot-spot composition algorithm is proposed in an attempt to achieve savings on both join and external sort operations. The proposed algorithm reduces the effort of performing the join operation by using a novel hot-spot technique. Several experiments have been conducted, and it is shown that the hot-spot composition algorithm outperforms other algorithms under almost every condition. The composition operation is implemented as a primitive operation in the algorithm