A truncating hash algorithm for processing band-join queries

The truncating-hash band join algorithm for evaluating band joins is described. This algorithm is based on the idea of truncating join attribute values in order to execute band joins in a way similar to hash join algorithms for equijoins. Unlike previously proposed algorithms for band joins, it does not sort either of the input relations during its execution. A comparison between the truncating-hash band join algorithm and previous algorithms for band joins using an analytical model is presented. The model also compares an evaluation of band join for a parallel implementation on a shared-nothing multiprocessor system. The results show that the truncating-hash band join algorithm outperforms the other band join algorithms because of a significantly lower CPU cost