The reason why need to do it like this instead of relying on a trigger
is because the entry in final_lines is created first and the final_shots
are populated. If we first the trigger on final_lines it is not going
to find any shots; if we fire it as a row trigger on final_shots it
would try to label every point in sequence as it is imported; finally if
we fire it as a statement trigger on final_shots we have no idea which
sequence was imported.