How to calculate N root of X in query

[ragava28]

Hi all,

I want to calculate n√X (n root of X) in Teiid query.

S= n√X  Where n= 1.89  & x is any input value

Looking at  internet article I wrote below query Nth root of a number

SELECT POWER(Convert(27,bigdecimal),Convert(1/1.89,bigdecimal))

SELECT POWER(27,1/1.89)

for both of the queries I am getting same error. Any thoughts how we can execute above formula ?

[shawkins]

The power function expects a double and 1/1.89 is bigdecimal.  Teiid treats the conversion of bigdecimal/numeric to double as potentially narrowing, which will depend on the exact value.  In this case unfortunately a cast is needed -

SELECT POWER(27, cast(1/1.89 as double))

You can see there is slight difference in the values:

SELECT 1/cast(1.89 as double) = 1/1.89