Session help?

[eluser]nguyenbatbinh[/eluser]
I don't know place session saved in codeigniter, when I used $this->session->set_userdata()

Ex:
$newdata = array(
'username' => 'johndoe',
'email' => '[email protected]',
'logged_in' => TRUE
);

$this->session->set_userdata($newdata);

Please help me!