SNOW-670332: Creating procedure using functions with variable arguments (*args)

[krish-adi]

Trying to create a UDF using the snowflake connector by executing this statement. This seems to work for creating a UDF, but not for a Store Procedure. It seems that, while the statement is executed, there is an AST Parser that is executed to check for the arguments.

I would like to take in variable arguments, so that I could modify my function depending on the requirements. Is there a way to achieve what I am trying to do, or by pass the limitation?

1. What did you do?

create or replace procedure var_arg_proc(arg_1 STRING)
    returns STRING
    language python
    runtime_version = '3.8'
    packages = ('snowflake-snowpark-python')
    handler = 'my_function'
AS
$$
from snowflake.snowpark.session import Session

def my_function(session: Session, *args):
    return arg[0]
$$;

2. Can you set logging to DEBUG and collect the logs?

100357 (P0000): Python function is defined with 1 arguments (including session), but stored procedure definition
contains 1 arguments. Python function arguments are expected to be session and stored procedure defined 
arguments in function VAR_ARG_PROC with handler my_function

[sfc-gh-sfan]

@krish-adi : Can you post this in https://github.com/snowflakedb/snowpark-python instead? I'm going to close this one.

[sfc-gh-sfan]

Sorry I misread, but this really has nothing to do with either the connector or snowpark api. Let's just keep it here.

[krish-adi]

I'll delete the one I posted in snowpark then.

[sfc-gh-sfan]

@krish-adi : sorry for the confusion, we could keep it here.

[sfc-gh-sfan]

Using *args in general does not make sense because the definition of the UDF/SP contains the number of arguments as well. I'm a bit surprised that it would work with python UDF. How would you pass in variable arguments if the definition of the UDF only takes one argument?

[krish-adi]

When I define the UDF/SP I programmatically add or remove the arguments using string manipulation.

But, when I actually write the handler, I don't want to do this. And I pass *args to the function. This works fine with a handler for functions, but not for a SP handler. For now, I've resorted to use string manipulation.

[sfc-gh-yixie]

@sfc-gh-sfan Does the SP server check the arguments of the handler function? We can remove this validation.

[sfc-gh-sfan]

@sfc-gh-yixie : Yes. I just checked and it seems like in UDF the check considered varargs, but not SP. We should improve our validation, instead of removing it. I added an internal ticket for it and we will try to address this in the next couple of weeks. Please be aware that the snowflake release itself also takes time.

[sfc-gh-sfan]

And again, thanks for raising it to us!