Double Hashing is Computable and Randomizable with Universal Hash Functions
Abstract
Universal has functions that exhibit c log n-wise independence are shown to give a performance in double hashing and virtually any reasonable generalization of double hashing that has an expected probe count of (1)/1-alpha + epsilon for the insertion of the alpha-th item into a table of size n, for any fixed alpha less than 1 and epsilon greater than 0. This performance is within epsilon of optimal. These results are derived from a novel formulation that overestimates the expected probe count by underestimating the presence of partial items already inserted into the hash table, and from a sharp analysis of the underlying stochastic structures formed by colliding items.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1995
- Accession Number
- AD1020222
Entities
People
- Alan Siegel
- Jeanette P. Schmidt
Organizations
- Courant Institute of Mathematical Sciences, NYU