  In a holographic superfluid disk, when the rotational velocity is large
enough, we find a giant vortex will form in the center of the system by merging
several single charge vortices at some specific rotational velocity, with a
phase stratification phenomenon for the order parameter. The formation of a
giant vortex can be explained as there is not enough space for a standard
vortex lattice. Keep increasing the rotational velocity the giant vortex will
disappear and there will be an appearance of a superfluid ring. In the giant
vortex region, the number of vortices measured from winding number and
rotational velocity always satisfies the linear Feynman relation. However, when
the superfluid ring starts to appear, the number of vortices in the disk will
decrease though the rotational velocity is increasing, where most of the order
parameter is suppressed.
