Some characteristics of sorting computing systems using random access storage devices

The substantial differences in characteristics of random access storage and tape devices dictate that concepts and objectives of computer program design be considered from the viewpoint of the external file medium used. This is particularly true in the case of sorting. In a tape-oriented system, the major sorting problem is that of minimizing merge time despite the limited orders of merge possible. In contrast, sorting in a random access-oriented system encourages the selection of the optimum order of merge from many possible orders. The latter problem is discussed in this paper, along with criteria developed for determining the optimum order of merge according to the various properties of random access storage devices. Attention is also given to the problem of key sorting versus record sorting and the possibly serious disadvantage of key sorting on a random access system.