reducebykeylocally专题

Spark算子:RDD键值转换操作(3)–groupByKey、reduceByKey、reduceByKeyLocally

groupByKey def groupByKey(): RDD[(K, Iterable[V])] def groupByKey(numPartitions: Int): RDD[(K, Iterable[V])] def groupByKey(partitioner: Partitioner): RDD[(K, Iterable[V])] 该函数用于将RDD[K,V]中每个K对应