REGR_COUNT
Returns the count of all rows in an expression pair.
	Returns the count of all rows in an expression pair. The function eliminates expression pairs where either expression in the pair is NULL. If no rows remain, the function returns 0.
Syntax
SELECT REGR_COUNT ( expression1, expression2 )
Parameters
- expression1
- The dependent DOUBLE PRECISIONexpression
- expression2
- The independent DOUBLE PRECISIONexpression
Examples
=> SELECT REGR_COUNT (Annual_salary, Employee_age) FROM employee_dimension;
 REGR_COUNT
------------
      10000
(1 row)