SQRT function
The SQRT function returns the square root of a numeric value. The square root is a number multiplied by itself to get the given value.
Syntax
SQRT (expression)
Argument
 expression

The expression must have an integer, decimal, or floatingpoint data type. The expression can include functions. The system might perform implicit type conversions.
Return type
SQRT returns a DOUBLE PRECISION number.
Examples
The following example returns the square root of a number.
select sqrt(16); sqrt  4
The following example performs an implicit type conversion.
select sqrt('16'); sqrt  4
The following example nests functions to perform a more complex task.
select sqrt(round(16.4)); sqrt  4
The following example results in the length of the radius when given the area of a circle. It calculates the radius in inches, for instance, when given the area in square inches. The area in the sample is 20.
select sqrt(20/pi());
This returns the value 5.046265044040321.
The following example returns the square root for COMMISSION values from the SALES table. The COMMISSION column is a DECIMAL column. This example shows how you can use the function in a query with more complex conditional logic.
select sqrt(commission) from sales where salesid < 10 order by salesid; sqrt  10.4498803820905 3.37638860322683 7.24568837309472 5.1234753829798 ...
The following query returns the rounded square root for the same set of COMMISSION values.
select salesid, commission, round(sqrt(commission)) from sales where salesid < 10 order by salesid; salesid  commission  round ++ 1  109.20  10 2  11.40  3 3  52.50  7 4  26.25  5 ...
For more information about sample data in Amazon Redshift, see Sample database.