Module hash4j
Package com.dynatrace.hash4j.distinctcount
package com.dynatrace.hash4j.distinctcount
Algorithms and data structures for approximate distinct counting
-
ClassDescriptionA utility functions for distinct counting.A HyperLogLog implementation for approximate distinct counting.A distinct count estimator for HyperLogLog.A martingale estimator, that can be used in conjunction with a distinct counter such as
HyperLogLogorUltraLogLogto obtain slightly more accurate estimates for non-distributed data streams than the corresponding standard estimators.An observer of state changes of distinct counters such asHyperLogLogorUltraLogLog.A sketch for approximate distinct counting that is more space efficient than HyperLogLog as described in Otmar Ertl, UltraLogLog: A Practical and More Space-Efficient Alternative to HyperLogLog for Approximate Distinct Counting, 2023A distinct count estimator for UltraLogLog.