kll_sketch_get_n_double function

Applies to: Databricks Runtime 18.0 and later

Returns the number of items that have been added to a double KLL sketch.

Syntax

kll_sketch_get_n_double ( sketch )

Arguments

• sketch: A BINARY expression containing a serialized DOUBLE KLL sketch.

Returns

A BIGINT representing the total count of items in the sketch.

Notes

• Returns the exact count of items added, not an estimate.
• Returns 0 for an empty sketch.

Examples

> WITH sketch_data AS (
    SELECT kll_sketch_agg_double(measurement) AS sketch
    FROM VALUES (1.23), (2.34), (3.45) AS T(measurement)
  )
  SELECT kll_sketch_get_n_double(sketch) FROM sketch_data
  3

Related functions

• kll_sketch_agg_double aggregate function
• kll_sketch_get_n_bigint function
• kll_sketch_get_n_float function