Returns the sample covariance of a set of number pairs.

Syntax 1

COVAR_SAMP( dependent-expression, independent-expression )

Syntax 2

COVAR_SAMP( dependent-expression, independent-expression ) 
OVER ( window-spec )

window-spec : see Syntax 2 instructions in the Remarks section below

Parameters

Remarks

This function converts its arguments to DOUBLE, performs the computation in double-precision floating point, and returns a DOUBLE as the result. If the function is applied to an empty set, then it returns NULL.

Both dependent-expression and independent-expression are numeric. The function is applied to the set of (dependent-expression, independent-expression) pairs after eliminating all pairs for which either dependent-expression or independent-expression is NULL.

For more information about the statistical computation performed, see Mathematical formulas for the aggregate functions.

Syntax 2 represents usage as a window function in a SELECT statement. As such, elements of window-spec can be specified either in the function syntax (inline), or in conjunction with a WINDOW clause in the SELECT statement. See the window-spec definition provided in WINDOW clause.

For more information about using window functions in SELECT statements, including working examples, see Window functions.

See also

• COVAR_POP function [Aggregate]
• SUM function [Aggregate]

Standards and compatibility

Example

The following example returns the value 74782.94600540561.

SELECT COVAR_SAMP( Salary, ( YEAR( NOW( ) ) - YEAR( BirthDate ) ) )
FROM Employees;