title: What's the difference between php_pdo_pgsql and php_pgsql PHP extensions?
body: <p>My default php.ini file lists both extensions (installed via brew), and I sometimes see different variations on Linux (AMZN vs Centos) with the <code>_pdo_</code> bit. What is the difference?</p>
  
  <p>Update: I was getting errors saying <code>pg_connect</code> not found and this seems to be part of the non-PDO version. To get this installed on Mac via brew, I needed to add support by running <code>brew reinstall php56 --with-postgresql</code> </p>