Snowflake Java UDF can't return an array of floats?

Question

I'm trying to return an array of Floats in a Java UDF, but Snowflake throws an error:

create or replace function float_array_test()
returns array
language java
handler='MyClass.test'
as
$$
    class MyClass {
        public static Float[] test() {
            return new Float[] {1.1, 2.2};
        }
    }
$$;

Error:

100315 (P0000): Error while compiling source: /InlineCode.java:4: error: incompatible types: double cannot be converted to Float
            return new Float[] {1.1, 2.2};

Any way to fix?

Answer 1

Check the docs for allowed types: float is ok, but Float is unsupported.

• https://docs.snowflake.com/en/developer-guide/udf/java/udf-java-designing.html#arrays-and-variable-number-of-arguments

Therefore, this is the code fixed:

create or replace function float_array_test()
returns array
language java
handler='MyClass.test'
as
$$
    class MyClass {
        public static float[] test() {
            return new float[] {(float)1.1, (float)2.2};
        }
    }
$$;

But beware of the error incompatible types: double cannot be converted to Float , that's why I had to cast the hard-coded doubles to float.

An even better solution is to use doubles in Java land, which will be converted to floats in SQL land without precision loss:

create or replace function float_array_test()
returns array
language java
handler='MyClass.test'
as
$$
    class MyClass {
        public static double[] test() {
            return new double[] {1.1, 2.2};
        }
    }
$$;