In this paper we present a paradigm for solving external-memory problems, and illustrate it by algorithms for matrix multiplication, sorting and list ranking. Our paradigm is based on the use of BSP algorithms. The correspondence is almost perfect, and especially the notion of x-optimality carries over to algorithms designed according to our paradigm.
The advantages of the approach are similar to the advantages of BSP algorithms for parallel computing: scalability, portability, predictability. The performance measure here is the total work, not only the number of I/O operations as in previous approaches. So the predicted performances are more useful for practical applications.