title: How to delete unused sequences?
body: <p>We are using PostgreSQL. My requirement is to delete unused sequences from my database.
  For example, if I create any table through my application, one sequence will be created, but for deleting the table we are not deleting the sequence, too. If want to create the same table another sequence is being created.</p>
  
  <p>Example: table: <code>file</code>; automatically created sequence for <code>id</code> coumn: <code>file_id_seq</code></p>
  
  <p>When I delete the table <code>file</code> and create it with same name again, a new sequence is being created (i.e. <code>file_id_seq1</code>). I have accumulated a huge number of unused sequences in my application database this way.</p>
  
  <p>How to delete these unused sequences?</p>