In #1746, we added a validation in xr.DataArray.__setitem__ whether the coordinates consistency of array, key, and values are checked.
In the current implementation, we call xr.DataArray.__getitem__ to use the existing coordinate validation logic, but it does unnecessary indexing and it may decrease the __setitem__ performance if the arrray is multidimensional.

We may need to optimize the logic here.

Is it reasonable to constantly monitor the performance of basic operations, such as Dataset construction, alignment, indexing, and assignment?
(or are these operations too light to make a performance monitor?)

cc @jhamman @shoyer