Merging on the BSP model

Abstract

The design of complex parallel algorithms relies heavily on a set of primitive operations. In this work, we examine the problem of merging two sorted sequences in an architecture independent setting. We derive parallel algorithms that can be used on a variety of parallel machines and whose performance can be reliably predicted if these algorithms are analyzed under the bulk-synchronous parallel (BSP) model. While our algorithms are fairly simple themselves, description of their performance in terms of the BSP parameters is somewhat complicated. The main reward for quantifying these complications, is that it enables parallel software to be written once and for all that can be migrated efficiently among a variety of parallel platforms. The optimal merging algorithm presented in this work achieves asymptotically optimal parallel efficiency compared to any optimal sequential merging algorithm.