title: What is the best index for postgresql timestamp
body: <p>I have searched a lot but has not found the answer for the following question. I have a table with lots of record (in the order of 100M) and I want to run the following query on it :</p>
  
  <pre><code>Entity.objects.filter(creation_time__gte=some_date).order_by('id').all()[0]
  </code></pre>
  
  <p>and my table is something like follows :</p>
  
  <pre><code>class Entity(models.Model):
      creation_time = models.DateTimeField(null=True, blank=True)
      # Other fields
  </code></pre>