--
-- acs_object__get_attr_storage_column/1
--
create or replace function acs_object__get_attr_storage_column(
  text
) returns text as $$

declare
        v_vals  alias for $1;
        v_idx   integer;
begin
        v_idx := strpos(v_vals,',');
        if v_idx = 0 or v_vals is null then 
           raise exception 'invalid storage format: acs_object.get_attr_storage_column %',v_vals;
        end if;

        return substr(v_vals,1,v_idx - 1);

end;$$ language plpgsql;