Hash-Based File Organization Utilizing Large Capacity Main Memory

Abstract

Due to the recent development of computer technology, it is possible to realize a reasonable amount of database on main memory. Although extensive use of main memory will produce good search performance and flexibility, conventional file organizations designed for disks seem not to be suitable for this environment. In this paper we first summarize characteristics of main memory compared with disks and problems to be solved in order to develop file organization suitable for main memory. B-trees and dynamic hashing schemes are well-known file organizations for database applications. Problems of direct implementations of these files under this environment are shown. A new file organization called structured variable length hashing scheme is introduced. Its access performance compared with conventional file organizations is presented. This comparison also shows that B-tree(and AVL tree) is preferable to B+tree in main memory environment.