title: Greatest Function in Netezza
body: <p>Am trying to find the equivalent statement to below in Netezza</p>
  
  <pre><code>greatest(table1.column1, table2.column2, table3.column3)
  </code></pre>
  
  <p>also</p>
  
  <pre><code>least(table1.column1, table2.column2, table3.column3)
  </code></pre>
  
  <p>all the columns are dates</p>
  
  <p>Any help is appreciated.</p>