title: Is there any reason to use a database connection pool with ActiveRecord?
body: <p>What are the benefits to using an external connection pool?</p>
  
  <p>I've heard that most other applications will open up a connection for each unit of work.  In Rails, for example, I'd take that to mean that each request could open a new connection.  I'm assuming a connection pool would make that possible.  </p>
  
  <p>The only benefit I can think of is that it allows you to have 1,000 frontend processes without having 1,000 postgres processes running. </p>
  
  <p>Are there any other benefits?</p>