php - Why is constructing PDO connection slow?

Question

I'm using PDO in my PHP application. It connects to a MySQL server on the same server:

$db = new PDO(mysql:host=localhost;dbname=test, $username, $password);

I created two pages with the same output (just some dummy data in plain html) one of which contains the call to create PDO. If I open the page that uses no connection the response is between 0.5 and 1 second quicker.

Answer 1

I've been doing some googling, and after reading this thread, I changed localhost to 127.0.0.1. That solves the problem....