pyspark.RDD.toLocalIterator() RDD.toLocalIterator(prefetchPartitions=False) 它是PySpark中RDD的一个方法。 返回一个包含该RDD中所有元素的迭代器。 这个迭代器消耗的内存和这个RDD中最大分区的内存一样大。 如果选择预选,即prefetchPartitions设为True,那它可能最多消耗两个最大分区的内存。 用这...Effective...
# PySpark 49000 4300 # Python 22000 2500 # Spark 55000 3000 Similarly, you can also calculate aggregation for all other functions specified in the above table. 3. Using Aggregate Functions on Series Sometimes you may need to calculate aggregation for a single column of a DataFrame. Since each ...
pyspark.RDD aggregate 操作详解 aggregate(zeroValue, seqOp, combOp) Aggregate the elements of each partition, and then the results for all the partitions, using a given combine functions and a neutral “zero value.” seqOp... ganglia gweb aggregate graphs & compare Hosts view ...