Since a file is usually stored on a disk, the response time to a query is dominated by the disk access time. In order to reduce the disk access time, a file can be stored on several independently accessible disks. In this paper, we discuss the problem of allocating buckets in a file among disks such that the maximum disk accessing concurrency can be achieved. We are particularly concerned with the disk allocation problem for binary Cartesian product files. A new allocation method is first proposed for the cases when the number (m) of available disks is a power of 2. Then it is extended to fit the cases where m is not a power of 2. The proposed algorithm has a "near" strict optimal performance for a partial match query in which the number of unspecified attributes is greater than a small number (5 or 6).
Bibliographical noteFunding Information:
This work was supported in part by NSF Grant DCR-8405498.
- Cartesian product files
- disk allocation
- file structures
- multi-key hasing
- partial match retrieval