I have a PL/SQL function with BOOLEAN in parameter:
function get_something(name in varchar2, ignore_notfound in boolean);
This function is
With Oracle 12, you can use the WITH clause to declare your auxiliary functions. I'm assuming your get_something function returns varchar2:
with
function get_something_(name varchar2, ignore_notfound number)
return varchar2
is
begin
-- Actual function call here
return get_something(name, not ignore_notfound = 0);
end get_something_;
-- Call auxiliary function instead of actual function
select get_something_('NAME', 1) from dual;
Of course, you could have also stored your auxiliary function somewhere in the schema as shown in this answer, but by using WITH, you don't have any external dependencies just to run this query. I've blogged about this technique more in detail here.