1.power function
Definition:
The Oracle PL/SQL, the POWER function is a built in function which takes two numeric inputs and returns numeric（数字的） result as first argument raised to second argument. The statement "POWER (a,b)" computes as ( a^b ).
Example Syntax:
POWER(x,y)
Here, "x" is the base while "y" is the exponent(指数).
Example usage：
The SQL query below calculates 2nd power of base 10.
select power（10,2） from dual；
Return result is 100.
