The answer (a) is correct, in general.
On Wed, Nov 7, 2012 at 6:09 PM, Ramasubramanian Narayanan
<[EMAIL PROTECTED]> wrote:
> Which of the following is correct w.r.t mapper.
> (a) It accepts a single key-value pair as input and can emit any number of
> key-value pairs as output, including zero.
> (b) It accepts a single key-value pair as input and emits a single key and
> list of corresponding values as output