I have a large database that needs auditing on a very detailed level (every select, update, insert, and delete, along with the actual text of the statement) for about half the users. I know how to do this (here is a related question for anyone interested), but I also realize we cannot do this for any extended amount of time because of how much quickly we would be collective massive amounts of data. So while there is a scheduled downtime coming up that we can implement the auditing, to change it to fine tune it (as management changes the request of what data they desire) or to disable it once we have enough data would require us having to take the database down to disable this. While this wouldn't be too horrible to do if we were able to schedule a short downtime late at night, it would be really nice if this could be avoided altogether, but every reference I've seen so far requires the database to be brought down and back up.
So, my question (which I believe to be general enough for the purposes of this site, even though the back story is specific) is if there is a way to enable/disable/change auditing without shutting down the database.
Edit: Oracle version 11r2. As for AUD$ vs. FGA, I'm not sure what FGA is, but AUD is the table which will hold the data, so I am assuming that one.