Save session->user_data in the DB only

[eluser]moot[/eluser]
Hello,

I've turned "sess_use_table" in config.php on. It works fine so far. However, I want to save certain session data in the database only; and not in the database and in the cookie.

Code:

// More specifically ...:
$this->session->set_userdata("is_logged_in", "1");

I don't want to have this status information in the cookie. Taking a look at the (unecrypted) cookie it seems to get saved both in the cookie and in the DB.

How can I store user data in the DB only?

Ideally, Codeigniter would save only the session id in the cookie and the rest in the DB. Maybe this can be achieved somehow without extending CI with an own lib.