Categories:: Data metric functions

ROWS_IN_PAST_HOUR_PERCENT (system data metric function)¶

Returns the percentage of column values that fall in the hour before the scheduled evaluation time. The percentage is computed over the total row count, including NULL values in the denominator.

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.ROWS_IN_PAST_HOUR_PERCENT(<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:

TIMESTAMP_LTZ
TIMESTAMP_TZ

Returns¶

The function returns a FLOAT value. The function returns NULL if the table or view has no rows.

Usage notes¶

The window starts 1 hour before the scheduled evaluation time and ends at the scheduled evaluation time; both boundaries are included. Values later than the scheduled evaluation time are not counted.
Unlike most system DMFs, this function measures rows that meet the expectation: a value of 0 means that no rows arrived in the window.

Example¶

Measure the percentage of rows that arrived in the past hour in the ingested_at column:

SELECT SNOWFLAKE.CORE.ROWS_IN_PAST_HOUR_PERCENT(
  SELECT
    ingested_at
  FROM events.tables.activity
);