numpyArray paramters.

from docs.derivative.ca/SelectTOP_Class :

[quote]
numpyArray(delayed=False, writable=False)→ numpy.array:

1.in which cases i should use “writable = True” what is the trade off ?
2.not sure from the docs how “delayed = True”
will affect case that i save the numpy array to disk every frame.

thank you.

Barak.