11 Facts About Tabulation hashing

In computer science, tabulation hashing is a method for constructing universal families of hash functions by combining table lookup with exclusive or operations.

Generalizations of tabulation hashing have been developed that can handle variable-length keys such as text strings.

Tabulation hashing is a universal hashing scheme, it can be used in any hashing-based algorithm in which universality is sufficient.

Therefore, tabulation hashing can be used to compute hash functions for hash chaining with a theoretical guarantee of constant expected time per operation.

However, universal Tabulation hashing is not strong enough to guarantee the performance of some other Tabulation hashing algorithms.

Nevertheless, despite only being 3-independent, tabulation hashing provides the same constant-time guarantee for linear probing.

Nevertheless, tabulation hashing is adequate to ensure the linear-expected-time construction of a cuckoo hash table for a static set of keys that does not change as the table is used.

Thorup provides a scheme based on tabulation hashing that reaches high degrees of independence more quickly, in a more constructive way.

The general type of Tabulation hashing scheme studied by Lemire uses a single table T indexed by the value of a block, regardless of its position within the key.

Mixed Tabulation hashing were introduced by Dahlgaard and Thorup as a way to strengthen the properties of Tabulation hashing while keeping nearly the same performance.

Mixed Tabulation hashing was shown in 2016 to have strong concentration with regards to k-partitions, which are useful in algorithms for counting distinct elements, such as the classical method by Flajolet and Martin.