Data base reorganization by clustering method

This paper is concerned with the problem of data re-allocation on a moving-head-disk, in order to minimize the average access time. From the analysis of the chronological accesses to the records during the reference period, the initial exploitation cost of the implementation is situated among all the possible ones, and the benefit of a reorganization may be evaluated. The reorganization itself is a two stage process: at first the file is partitioned by a clustering algorithm, and then, the clusters are allocated to cylinders. By the application of this method on a 11,000-record file, the access mean time was reduced by a factor 2.