Categories: Aggregate, Window

HLL

Uses HyperLogLog to return an approximation of the distint cardinality of the input.

Syntax

HLL(expression boolean) → varbinary

  • expression: Expression for which you want to know the number of distinct values.

Examples

SELECT HLL(TRUE)
-- sample return

HLL(expression float) → varbinary

  • expression: Expression for which you want to know the number of distinct values.

Examples

SELECT HLL(67.90)
-- sample return

HLL(expression varbinary) → varbinary

  • expression: Expression for which you want to know the number of distinct values.

HLL(expression date) → varbinary

  • expression: Expression for which you want to know the number of distinct values.

Examples

SELECT HLL('2021-06-15')
-- sample return

HLL(expression interval_year) → varbinary

  • expression: Expression for which you want to know the number of distinct values.

HLL(expression interval_day) → varbinary

  • expression: Expression for which you want to know the number of distinct values.

HLL(expression int64) → varbinary

  • expression: Expression for which you want to know the number of distinct values.

Examples

SELECT HLL(2021)
-- sample return

HLL(expression double) → varbinary

  • expression: Expression for which you want to know the number of distinct values.

Examples

SELECT HLL(45.7)
-- sample return

HLL(expression time) → varbinary

  • expression: Expression for which you want to know the number of distinct values.

HLL(expression int32) → varbinary

  • expression: Expression for which you want to know the number of distinct values.

Examples

SELECT HLL(2021)
-- sample return 1

HLL(expression varchar) → varbinary

  • expression: Expression for which you want to know the number of distinct values.

Examples

SELECT HLL('dremio')
-- sample return 1

HLL(expression timestamp) → varbinary

  • expression: Expression for which you want to know the number of distinct values.

Examples

SELECT HLL('2021-06-17 11:50:59')
-- sample return 1

Learn more about window functions.