An efficient external sorting algorithm

Abstract

This paper presents an optimal external sorting algorithm for two-level memory model. Our method is different from the traditional external merge sort and it uses the sampling information to reduce the disk I/Os in the external phase. The algorithm is efficient, simple and it makes a good use of memory available in the recent computer environment. Under the certain memory constraint, this algorithm runs with optimal number of disk I/Os and each record is exactly read twice and written twice.