  The issue of holographic mapping between bulk and boundary in the plane-wave
limit of AdS/SYM correspondence is reexamined from the viewpoint of correlation
functions. We first study the limit of large angular momentum for the so-called
GKP-W relation in supergeravity approximation, connecting directly the
effective action in the bulk and the generating functional of correlation
functions on the boundary. The spacetime tunneling picture which has been
proposed in our previous works naturally emerges. This gives not only a
justification of our previous proposal, with some important refinements, on the
mapping between bulk effective interaction and the CFT coefficients on the
boundary in the plane-wave limit, but also implies various insights on the
interpretation of holography in the plane-wave limit. Based on this result, we
construct a new `holographic' string field theory. We confirm for several
nontrivial examples that this gives the CFT coefficients derived by
perturbation theory on the gauge-theory side.
  Our results are useful for understanding how apparently different duality
maps proposed from different standpoints are consistent with each other and
with our definite spacetime picture for the AdS holography in the plane-wave
limit.
