What's the difference among ShuffledRDD, MapPartitionsRDD and ParallelCollectionRDD?
<p>I just use two different way to generate Spark RDD. And the results in Spark UI DAG chart are quite different.</p>

<p><a href="https://i.stack.imgur.com/bhVpu.png" rel="nofollow"><img src="https://i.stack.imgur.com/bhVpu.png" alt="enter image description here"></a></p>

<p><a href="https://i.stack.imgur.com/1BmNx.png" rel="nofollow"><img src="https://i.stack.imgur.com/1BmNx.png" alt="enter image description here"></a></p>

<p>Can someone teach me the differences, and in my work, the first one is faster than the second one with similar operation.</p>