Original ticket http://projects.scipy.org/numpy/ticket/1386 on 2010-01-31 by trac user oscar.bristol, assigned to unknown.

Assigning to a field in a scalar record array like this
B['a'] = A['a']
takes around 50 times as long as assigning like this:
B['a'][:] = A['a']
and 100 times as long as assigning to a size 1 record array.
I've attached a script (test.py) that compares scalars and size 1 arrays and the two different methods of indexing above. On my machine, the results are:

$ python test.py 100000
array, B['a'][:] = A['a'] 0.25 seconds
array, B['a'] = A['a'] 0.213 seconds
scalar, B['a'][:] = A['a'] 0.395 seconds
scalar, B['a'] = A['a'] 22.0 seconds