title: How to trigger a function by looking at time in database table
body: <p>I have rails 4 application and I want to trigger a rake task by looking at a time column in the database table.</p>
  
  <p>The rake task should get triggered when <code>Time.now</code> equals the time stored in the column of the table.</p>
  
  <p>How can I best approach this problem and solve it elegantly?</p>
  
  <p>My database is PostgreSQL.</p>