
cosmob.org
CoSMob | CoSMob BlogIn our last post we have seen how to use lambda expressions in order to aggregate data and compute mean using combineByKey() method. However, this method requires the computation of 2 values: sum and count. In this post, we will discover a simpler method to aggregate multiple attributes using the reduceByKey() method which will demonstrate that the combineByKey() can be useless as all possible computations can be done using reduceByKey()
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