title: Whats the difference between UNION and CROSS JOIN?
body: <p>I have been reading about this two possibilities but I'm not sure if I understood them properly.
  So <code>UNION</code> makes new rows with the union of the two queries data:</p>
  
  <pre><code>Table1     Table2
  ------     ------
    1           3
    2           4
  
  SELECT * FROM TABLE1
  UNION
  SELECT * FROM TABLE2
  
  Column1 
  ---------
     1        
     2
     3
     4
  ...
  </code></pre>
  
  <p>And <code>CROSS JOIN</code> makes Cartesian product of both tables:</p>
  
  <pre><code>SELECT * FROM TABLE1 
  CROSS JOIN TABLE 2
  
  Column1 | Column2
  -----------------
     1    |    3
     2    |    3     
     1    |    4 
     2    |    4 
  </code></pre>
  
  <p>Its that ok?</p>
  
  <p>Thanks for all.</p>