[Building Sakai] Overall usage statistics and SAKAI_EVENT

[Joshua Swink]

I'm trying to get overall usage statistics for our Sakai site.

First question: Why isn't the user id stored for a user.login event?
Was this considered a privacy issue? It would make this task a lot
easier.

Here is the query I'm using to get the number of people who used Sakai
in a single day. It relies on the assumption that any person who is
'present' at a '/presence/~%' location must be a user visiting its own
workspace. This is not a perfect assumption but it seems to be the
best I can do for now.

select distinct A.ref
    from sakai_event A, sakai_event B
    where
        A.event='pres.begin' and
        A.ref like '/presence/~%' and
        A.session_id = B.session_id and
        B.event = 'user.login' and
        B.event_date > to_date('2009-09-09 0:00:00', 'YYYY-MM-DD
HH24:MI:SS') and
        B.event_date < to_date('2009-09-10 0:00:00', 'YYYY-MM-DD HH24:MI:SS');

Josh