Codeigniter says only up to 4KB of data can be stored in a cookie. Does that mean each $this->session->userdata('something'); is one cookie, and i can have an unlimited number of them?
Because I used only ONE userdata session data, and it won't accept any more information since its already 4KB... Will this be fixed if I factor it all out and have many different $this->session->userdata()?
There should be no cookie limit to session data because the only thing stored in a cookie is the session ID, a long string of some sort. Actual session data, even when not stored in a DB, is stored in a file on the server identified by the ID. There is no need to use another library. And database session storage is recommended both for speed and security. As long as your database is secure, your session data will be. You can actually use sessions without using cookies at all by appending the session ID to the request as a query string, but I wouldn't recommend that unless you want to serve users who have cookies turned off for some reason.