Structured Permuting in Place on Parallel Disk Systems

The ability to perform permutations of large data sets in place reduces the amount of necessary available disk storage. The simplest way to perform a permutation often is to read the records of a data set from a source portion of data storage, permute them in memory, and write them to a separate target portion of the same size. It can be quite expensive, however, to provide disk storage that is twice the size of very large data sets. Permuting in place reduces the expense by using only a small amount of extra disk storage beyond the size of the data set. This paper features in-place algorithms for commonly used structured permutations. We have developed an asymptotically optimal algorithm for performing BMMC (bit-matrixmultiply/complement) permutations in place that requires at most 2N BD 2 l rank lg(M=B) m + 7 2 parallel disk accesses, as long as M 2BD, where N is the number of records in the data set, M is the number of records that can t in memory, D is the number of disks, B is th...

• Type: Conference
• Year: 1996
• Where: IOPADS
• Authors: Leonard F. Wisniewski
• Keywords: Data Set, Disk Storage, IOPADS 1996, Permutations