Linear Hashing with Separators—A Dynamic Hashing Scheme Achieving One-Access Retrieval

Abstract

A new dynamic hashing scheme is presented. Its most outstanding feature is that any record can be retrieved in exactly one disk access. This is achieved by using a small amount of supplemental internal storage that stores enough information to uniquely determine the current location of any record. The amount of internal storage required is small: typically one byte for each page of the file. The necessary address computation, insertion, and expansion algorithms are presented and the performance is studied by means of simulation. The new method is the first practical method offering one-access retrieval for large dynamic files. © 1988, ACM. All rights reserved.