Abstract:

F. Dehne, W. Dittrich, and D. Hutchinson, Efficient External Memory Algorithms by Simulating Coarse-Grained Parallel Algorithms, Proc. Symposium on Parallel Algorithms and Architectures (SPAA'97), Newport R.I., USA, June 1997.
 

External memory (EM) algorithms are designed for computational problems in which the size of the internal memory of the computer is only a small fraction of the problem size. For certain large scale applications this is necessarily true. Typically, the cost models proposed for external memory algorithms have measured only the number of I/O operations, and the algorithms have been specially crafted for the EM situation. In the past, several attempts have been made to relate the large body of work based on parallel algorithms to EM, but with limited success. In this paper we provide simulation techniques which produce efficient EM algorithms from efficient algorithms developed under BSP-like parallel computing models. Our techniques can accommodate one or multiple processors on the EM target machine, each with one or more disks, and they also adapt to the disk blocking factor of the target machine. In addition to the main simulation result we obtain a more comprehensive cost model for EM algorithms, which considers the total costs incurred by the algorithm including computation, I/O and communication costs.



Last modified: Wed Oct 27 14:32:10 EDT 1999