create table float4test (id serial primary key, nr float4);

create language plpgsql;

CREATE OR REPLACE FUNCTION in_test4(pnr float4) RETURNS integer AS $$
DECLARE
    datas RECORD;
BEGIN
    Insert into float4test (nr) values (pnr) returning id into datas; 

    RETURN datas.id;    
END;
$$ LANGUAGE plpgsql;

CREATE OR REPLACE FUNCTION in_test8(pnr float8) RETURNS integer AS $$
DECLARE
    datas RECORD;
BEGIN
    Insert into float4test (nr) values (pnr) returning id into datas; 

    RETURN datas.id;    
END;
$$ LANGUAGE plpgsql;