title: about Oracle parallel insert performance
body: <p>I have an sql like this:</p>
  
  <pre><code>Insert into A
  Select * from B;
  </code></pre>
  
  <p>Now I want it to run in parallel. My question is to parallelize the insert or select or both?  See the following sqls, can you tell me which one is correct or which one has best performance. I don't have dba permission, so I cann't check its execute plan.</p>
  
  <p>1)    <code>Insert /*+ parallel(A 6) */ into A select * from B;</code></p>
  
  <p>2)    <code>Insert  into A select/*+ parallel(B 6) */ * from B;</code></p>
  
  <p>3)    <code>Insert /*+ parallel(A 6) */ into A select /*+ parallel(B 6) */ * from B;</code></p>
  
  <p>Thank you!</p>