title: Retrieve the compressed (binary format) of the big column
body: <p>As <a href="https://stackoverflow.com/q/3801416/287948">remembered here</a>, when  storing documents (suppose <code>text</code> or <code>xml</code> datatypes and <em>EXTENDED</em> storage) with more than 2k, it is compressed. </p>
  
  <p>About table columns that was compressed, how to retrieve the compressed (binary format) of the column?</p>
  
  <hr>
  
  <p>NOTE - Typical applications:</p>
  
  <ul>
  <li><p>Operations as "<a href="https://crypto.stackexchange.com/a/44281/42893">long-term checksum</a> of the document", like <code>SHA256(compressed)</code>.<br/>PS: as it is a matter of convention, not needs complementar compression, inheriting the condition, <code>SHA256(less2k? text: compressed)</code>.</p></li>
  <li><p>Coping or downloading compressed documents directally (without CPU consume). <br/>PS: complementing operation (for "less than 2k row") with on-the-fly compression, when uniformity is required.</p></li>
  </ul>