With normal/small vines we mean the approx. 30 cm long vines, which are still the standard today.
They have, depending on their origin, a 28 - 35 cm long rootstock plus the scion of about 5 cm.
They are planted in such a way that the grafting union protrudes clearly from the ground, so that the scion has no ground contact.
Otherwise it may lead to the formation of scions roots and then to the repulsion of the rootstock. Scion roots are susceptible to phylloxera, so that they can multiply well again.