Categories: Aggregate, Window

COVAR_SAMP

Returns the sample covariance for non-NULL pairs across all input values.

Syntax

COVAR_SAMP(expression1 numeric, expression2 numeric) → double

• expression1: An expression that evaluates to a numeric type. This parameter is the dependent value.
• expression2: An expression that evaluates to a numeric type. This parameter is the independent value.

Examples

Aggregate function example

SELECT COVAR_SAMP(trip_distance_mi, fare_amount)
FROM Samples."samples.dremio.com"."NYC-taxi-trips"
-- 31.70536780565699

Aggregate function example using optional DISTINCT clause

SELECT COVAR_SAMP(DISTINCT trip_distance_mi, fare_amount)
FROM Samples."samples.dremio.com"."NYC-taxi-trips"
-- 31.7053678056971

Window function example

SELECT COVAR_SAMP(trip_distance_mi, fare_amount)
  OVER (PARTITION BY trip_distance_mi)
FROM Samples."samples.dremio.com"."NYC-taxi-trips"
-- 2.442515362986122e-15

Usage Notes

This function supports the use of ALL and DISTINCT:

SELECT COVAR_SAMP( [ { ALL | DISTINCT } ] expression1, expression2)