Spark 算子 reduceByKey vs groupByKey 對比

Spark 算子 reduceByKey vs groupByKey 對比 案例 準備測試數據 val data=sc.parallelize(Array("a","b","c","d","e","a","b","e","b","f")) reduceByKey val reduceData=data.map((_,1)).reduceByKey(_+_).collect() reduceData

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