Re: search_path for PL/pgSQL functions partially cached?

On Saturday, January 4, 2025, Jan Behrens <jbe-mlist(at)magnetkern(dot)de> wrote:

>
> CREATE FUNCTION "foo_impl"("query_p" TEXT, "search_path_p" TEXT)
> RETURNS "some_type"
> LANGUAGE plpgsql SET search_path FROM CURRENT AS $$
> DECLARE
> "old_search_path" TEXT;
> "result" "some_type";
> BEGIN
> "old_search_path" = current_setting('search_path');
> PERFORM set_config('search_path', "search_path_p", TRUE);
> EXECUTE "query_p" INTO "result";
> PERFORM set_config('search_path', "old_search_path", TRUE);
> RETURN "result";
> END;
> $$;
>

You might consider adding a polymorphic argument for the result type. Then
if you call the function with two different typed inputs it will be cached
once for each.

“ Likewise, functions having polymorphic argument types have a separate
statement cache for each combination of actual argument types they have
been invoked for, so that data type differences do not cause unexpected
failures.”

David J.