title: How to convert int column to float/double column in Cassandra database table
body: <p>I am using cassandra database in production.I have one column field in<br>
      a cassandra table e.g coin_deducted  is int data type. </p>
  
  <p>I need to convert coin_deducted in float/double data type. 
      But I tried to change data type by using alter<br>
      table command but cassandra is throwing incompatible issue while<br>
      converting int to float. Is there any way to do this?</p>
  
  <p>e.g: currently it is showing like: </p>
  
  <pre><code>   user_id | start_time | coin_deducted (int)                    
     122     | 26-01-01   | 12
  
  I want to be 
  
    user_id | start_time | coin_deducted (float)                    
     122     | 26-01-01   | 12.0
  </code></pre>
  
  <p>Is it possible to copy entire one column field into new added column 
     field in same table?</p>