  The diffractive production of vector mesons in deep inelastic scattering
(DIS) is calculated in the McLerran-Venugopalan model. This is relevant when
large parton densities are probed by the virtual photon, as is the case at
small Bjorken x or in DIS off nuclei. We investigate differences between the
exclusive production (when the target doesn't break up) which dominates at
small momentum transfer squared |t|, and the diffractive production (when the
target scatters inelastically) which dominates at large |t|.
