title: What is the relationship between tasks and partitions?
body: <p>Can I say? </p>
  
  <ol>
  <li><p>The number of the Spark tasks equal to the number of the Spark partitions?</p></li>
  <li><p>The executor runs once (batch inside of executor) is equal to one task? </p></li>
  <li><p>Every task produce only a partition? </p></li>
  <li><p>(duplicate of 1.)</p></li>
  </ol>