In order to reduce the disk access time, a database can be stored on several simultaneously accessi- ble disks. In this paper, we are concerned with the dynamic d-attribute database allocation problem for range querie...In order to reduce the disk access time, a database can be stored on several simultaneously accessi- ble disks. In this paper, we are concerned with the dynamic d-attribute database allocation problem for range queries. An allocation method, called coordinate modulo allocation method, is proposed to al- locate data in a d-attribute database among disks so that the maximum disk accessing concurrency can be achieved for range queries. Our analysis and experiments show that the method achieves the optimum or near-optimum parallelism for range queries. The paper offers the conditions under which the method is optimal. The worst case bounds of the performance of the method are also given. In addi- tion, the parallel algorithm of processing range queries is described at the end of the paper. The meth- od has been used in the statistic and scientific database management system which is being designed by us.展开更多
文摘In order to reduce the disk access time, a database can be stored on several simultaneously accessi- ble disks. In this paper, we are concerned with the dynamic d-attribute database allocation problem for range queries. An allocation method, called coordinate modulo allocation method, is proposed to al- locate data in a d-attribute database among disks so that the maximum disk accessing concurrency can be achieved for range queries. Our analysis and experiments show that the method achieves the optimum or near-optimum parallelism for range queries. The paper offers the conditions under which the method is optimal. The worst case bounds of the performance of the method are also given. In addi- tion, the parallel algorithm of processing range queries is described at the end of the paper. The meth- od has been used in the statistic and scientific database management system which is being designed by us.
