Inefficient Users Online Script - suggestions to improve

[Dudaa]

Traffic has grown a lot and I'm looking to rebuild the users online part.

This is what I currently have

function showusersonline($hidden = false) {
	mysql_query("INSERT INTO usersonline(timestamp, ip, location) VALUES ('".time()."', '".$_SERVER['REMOTE_ADDR']."', '".mysql_real_escape_string(LOCATION)."')") or die('Error user 01 '.mysql_error());
	mysql_query("DELETE FROM usersonline WHERE timestamp < (".time()." - 900)") or die('Error user 02 '.mysql_error());
	$count_users = mysql_num_rows(mysql_query('SELECT DISTINCT ip FROM usersonline')) or die('Error user 03 '.mysql_error());
	if($hidden) return '';
	return $count_users . ' User'.(($count_users == 1) ? '' : 's').' Online';
}

The whole thing works fine but I'm wondering is their any way of making it more efficient or faster?

I've looked at doing a little mt_rand(1,2) and only delete them on average every second page load reducing it by one query. It might be out by a second or two but I'm not that fussy.

Anyone have any other suggestions on how to make it all more efficient and less of a resource hog?

I know it's basic but that's the level I'm at and why I'm making this topic looking for suggestions from more experienced members.

[dalecosp]

I don't have any real good ideas, AFAIK, but these thoughts come to mind.

• Use a variable in place of the time() -900 call.

• Put DELETE first, then INSERT, and for your $count call PHP's [man]mysql_affected_rows/man.

• And if it's hidden, why do the SQL at all? Just return your null string immediately.

Like I said, out of context, I've no clue whether these will help or break your setup. I *hope* it's helpful thinking, though. 🙂

[Dudaa]

Cheers thanks for that dalecosp.

I'll do the variable thing and the mysql_affected_rows()
Your third point about the hidden is so obvious it's annoying. I'll still insert the data as while I don't want the information displayed on certain pages I still want it counted when people are visiting these pages but your right their is definitely no need for the SELECT part in this case.

Thanks again for your feedback much appreciated.