$_SESSION - how long will it keep around?
<p>I am a little confused about the session management in PHP.  A lot of focus in the docs is devoted to the magic PHPSESSID cookie.  I program Ajax and am actually thinking of getting rid of cookies.  I understand that I can do so in the php.ini file.  It also seems possible to suppress the PHPSESSID by means of a simple ini_set("session.use_cookies",0) at the top of my login script.  Don't get me wrong, I do want sessions.  My Ajax hand-shakes will, where required, POST the session id.  From the cookie-centric docs, one just gains the impression that all session expiry handling is done via the time stamp on the cookie.  I am unclear on how exactly a timestamp of a cookie can prompt the server to expire the session cache over a stateless connection?  Put another way, in a cookie-less setup, how can I instruct the server to clean down the session cache after a while?  Would I still be calling session_set_cookie_params?  Seems quaint...</p>

<p>If I understand well, then I should call sessionID(sid) and check the return for "" to make out whether "sid" is dead.  Correct?</p>

<p>Thanks.</p>
