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Abstract

Discusses hashing, an information storage and retrieval technique useful for implementing many of the other structures in this book. The concepts underlying hashing are presented, along with 2 implementation strategies. The chapter also contains an extensive discussion of perfect hashing, an important optimization in information retrieval, and an O(n) algorithm to find minimal perfect hash functions for a set of keys

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Abstract

Presents an overview of Boolean operations, which are one means of expressing queries in information retrieval systems. The concepts of Boolean operations are introduced, and 2 implementations based on sets are given. One implementation uses bit vectors; the other, hashing. The relative performance characteristics of the approaches are shown