Index compression using 64-bit words

Abstract

Modern computers typically make use of 64-bit words as the fundamental unit of data access. However the decade-long migration from 32-bit architectures has not been reflected in compression technology, because of a widespread assumption that effective compression techniques operate in terms of bits or bytes, rather than words. Here we demonstrate that the use of 64-bit access units, especially in connection with word-bounded codes, does indeed provide the opportunity for improving the compression performance. In particular, we extend several 32-bit word-bounded coding schemes to 64-bit operation and explore their uses in information retrieval applications. Our results show that the Simple-8b..