title: shrinking a column in oracle
body: <p>Lets say i have a table with the following definition</p>
  
  <pre><code>create table dummy (col1 number(9) not null)
  </code></pre>
  
  <p>All the values in this dummy.col1 are 7 digit long. Now i want to reduce the length of this column from 9 - 7 using alter command. Oracle gives me error that <strong>column to be modified must be empty to decrease precision or scale</strong>. Makes sense.</p>
  
  <p>I want to ask is there any work around to reduce the column size? </p>
  
  <ul>
  <li>I can't delete the values in the column. </li>
  <li>I can't copy values from this column to another since it has trillions of data. </li>
  </ul>