Vertica has a built-in function to calculate the arithmetic square root a number called SQRT and another built-in function to calculate the arithmetic cube root of a number called CBRT.
Example:
dbadmin=> SELECT sqrt(9);
sqrt
------
3
(1 row)
dbadmin=> SELECT cbrt(27);
cbrt
------
3
(1 row)
But what if I need a function to calculate the arithmetic nth root of a number? No problem. I can create my own!
dbadmin=> CREATE OR REPLACE FUNCTION nrt (x FLOAT, y FLOAT) RETURN FLOAT
dbadmin-> AS
dbadmin-> BEGIN
dbadmin-> RETURN POWER(x,(1/y));
dbadmin->
dbadmin-> END;
CREATE FUNCTION
dbadmin=> SELECT nrt(390625, 4);
nrt
-----
25
(1 row)
dbadmin=> SELECT nrt(256, 4);
nrt
-----
4
(1 row)
dbadmin=> SELECT nrt(27, 3);
nrt
-----
3
(1 row)
dbadmin=> SELECT nrt(9, 2);
nrt
-----
3
(1 row)
