apache-spark,partitioning , How many spark elements per partition


How many spark elements per partition

Question:

Tag: apache-spark,partitioning

Is there any way to get the number of elements in a spark RDD partition, given the partition ID? Without scanning the entire partition.

Something like this:

Rdd.partitions().get(index).size()

Except I don't see such an API for spark. Any ideas? workarounds?

Thanks


Answer:

You can try this (in Scala):

rdd.partitions.size

Edit: Sorry, I misunderstood you. This will give you a new rdd with elements that represent sizes of each partition:

rdd.mapPartitions(iter => Array(iter.size).iterator, true) 

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