Cascade hash tables: a series of multilevel double hashing schemes with O(1) worst case lookup time

TL;DR

This paper introduces cascade hash tables, a multilevel double hashing approach that achieves constant worst-case lookup time with high load factors by reducing collisions through multiple hash table levels.

Contribution

It presents a novel multilevel hashing scheme that improves worst-case lookup time and collision management in hash tables.

Findings

Achieves O(1) worst-case lookup time in experiments.

Supports high load factors of 70%-85%.

Reduces collisions effectively through multilevel design.

Abstract

In this paper, the author proposes a series of multilevel double hashing schemes called cascade hash tables. They use several levels of hash tables. In each table, we use the common double hashing scheme. Higher level hash tables work as fail-safes of lower level hash tables. By this strategy, it could effectively reduce collisions in hash insertion. Thus it gains a constant worst case lookup time with a relatively high load factor(70%-85%) in random experiments. Different parameters of cascade hash tables are tested.