Invoking UDF that doesn't have parameters without paranthesis

[Nagarajan Chinnasamy]

Hi,

Am developing a UDF called SESSION_ID as detailed in issue:

    https://issues.apache.org/jira/browse/DRILL-5043

It does not take any input parameters. Now, I can only invoke it using
parenthesis as in:

    SELECT SESSION_ID() FROM (Values(1));

I would like to know what do I need to do if I need to invoke it without
paranthesis like:

    SELECT SESSION_ID FROM (Values(1));

Appreciate your input.

Best Regards,
Nagu.