how know if a page is used by the menu ?

Hi! I’m developping a community website and I need to manage a lots of menus and submenus.
I wonder if it’s possible to know if a page is used in my menu in the ‘menu management’. I’ve checked in the database but i’ve no idea…
If someone found a way, i’ll develop a plugin to do that ; I think it could be a good enhancement for the project WP…

Thanks.