[mgkimsal]

IIRC E_DEPRECATED notices are triggered when deprecated stuff is referenced.

http://php.net/manual/en/errorfunc.constants.php

E_DEPRECATED - Run-time notices. Enable this to receive warnings about code that will not work in future versions. (Since PHP 5.3.0)

[RossM]

Indeed; in fact this update issues an E_DEPRECATED warning when you attempt to connect to a MySQL database using the old MySQL extension.