title: Update the results of a SELECT statement
body: <p>Oracle lets you update the results of a SELECT statement.</p>
  
  <pre><code>UPDATE (&lt;SELECT Statement&gt;)
  SET &lt;column_name&gt; = &lt;value&gt;
  WHERE &lt;column_name&gt; &lt;condition&gt; &lt;value&gt;;
  </code></pre>
  
  <p>I suppose that this could be used for updating columns in one table based on the value of a matching row in another table.</p>
  
  <p>How is this feature called, can it efficiently be used for large updates, does it work when the SELECT joins multiple tables, and if so, how?</p>