Module hll

common_function::aggrs::approximate

Module hll 

Source
Expand description

Two UDAFs are implemented for HyperLogLog:

  • hll: Accepts a string column and aggregates the values into a HyperLogLog state.
  • hll_merge: Accepts a binary column of states generated by hll and merges them into a single state.

The states can be then used to estimate the cardinality of the values in the column by hll_count UDF.

Structs§

HllState

Constants§

DEFAULT_PRECISION 🔒
HLL_MERGE_NAME
HLL_NAME

Type Aliases§

HllStateType 🔒