Categories:: Data metric functions

HARMONIC_MEAN (system data metric function)¶

Returns the harmonic mean of the nonzero values for the specified column in a table. Zero values are excluded, because their reciprocal is undefined; negative values are included.

This topic provides the syntax for calling the function directly. To learn how to associate the function with a table or view so it runs at regular intervals, see Associate a DMF.

Syntax¶

SNOWFLAKE.CORE.HARMONIC_MEAN(<query>)

Arguments¶

query: Specifies a SQL query that projects a single column.

Allowed data types¶

The column projected by the query must have one of the following data types:

FLOAT
NUMBER

Returns¶

The function returns a FLOAT value. The function returns NULL if the column contains no nonzero values.

Example¶

Measure the harmonic mean of the speed column:

SELECT SNOWFLAKE.CORE.HARMONIC_MEAN(
  SELECT
    speed
  FROM iot.tables.readings
);