title: Impact on changing the data type from char to varchar2
body: <p>Can anyone tell me will there be any impact on changing the datatype of a column from char to <code>varchar2</code>.</p>
  
  <p>Because the issue i am facing is when i fire a select query i.e</p>
  
  <pre><code>select * from table_name where column_name in ('X','Y','Z');
  </code></pre>
  
  <p>The above query is returning only few rows. And recently the <code>column_name</code> data type was changed from char to <code>varchar</code>. The rows returned are the rows after the data type was changed.</p>