  The purpose of this work is to examine the structure of optimal dual fusion
frames and get more flexibility in the use of dual fusion frames for erasures
of subspaces. The problem of optimal Q-component preserving dual fusion frames
was considered by S. B. Heineken and P. M. Morillas. We deal with differences
and advantages of dual fusion frames with respect to Q-component preserving
duals to show that our approach provides concrete structures for reconstruction
of elements underlying Hilbert spaces. We then study the relation between local
and global optimal duals, by a new notion called partial optimal duals which
leads to some applicable results. In the sense that, we obtain an overcomplete
frame and a family of associated optimal duals by a given Riesz fusion basis.
We present some examples to exhibit the effect of error rate when dual fusion
frames and Q-component preserving duals are used to reconstruction.
