title: Drupal is extremely slow handling simple AJAX calls
body: <p>I wrote a simple AJAX callback function in Drupal that performs a query to the DB and returns a JSON formatted string. Nothing fancy, the standard AJAX declaration in the module with a modest amount of information (less than 4KB). The query to the database takes 52ms. Drupal adds around 320ms of overhead for a total of 370ms + latency. And that in my development machine (only one user)...</p>
  
  <p>Is this normal? Do you know how you can decrease that huge overhead?</p>
  
  <p>Context:
  - Clean install
  - No extra modules
  - Without the Drupal cache. I want to know the real performance of Drupal (I'm starting to be really concerned about how slow this is - I didn't expect it).
  - APC opcode cache activated</p>
  
  <p>Thanks in advance,
  Juan</p>
  
  <p>P.D.: At some point I was wondering what'd be the real effect of no having a connection pool to the DB like Java frameworks, and running the whole PHP script every time. Maybe I'm starting to see the performance problems of using PHP?</p>