COVAR_POP
Returns the population covariance for a set of expression pairs.
	Returns the population covariance for a set of expression pairs. The return value is of type DOUBLE PRECISION. COVAR_POP eliminates expression pairs where either expression in the pair is NULL. If no rows remain, the function returns NULL.
Syntax
SELECT COVAR_POP ( expression1, expression2 )
Parameters
- expression1
- The dependent DOUBLE PRECISIONexpression
- expression2
- The independent DOUBLE PRECISIONexpression
Examples
=> SELECT COVAR_POP (Annual_salary, Employee_age)
      FROM employee_dimension;
     COVAR_POP
-------------------
 -9032.34810730019
(1 row)