Which are the functions of the mapping phase and reduce phase in mapreduce?
in the mapping phase, raw data is transformed into a set of pairs, whereas the reduce phase merges the values from the previous phase.
in the mapping phase, the pairs are merged whereas in the reduce phase raw data is transformed into a set of pairs.
the mapping phase includes both the raw data transformation to pairs and the merging of the transformed values, whereas the reduce phase performs the required outputs to disk and print out.
the mapping phase performs the required outputs to disk and print out whereas the reduce phase includes both the raw data transformation to pairs and the merging of the transformed values