But Peter is right that there is no need to presist attributes your application associate with user session via hunchentoot mechanism. You can just store the attributes your application intorduces in your own DB, using sessionID as a subkey.
The Ron's solution ensures another aspect - when hunchentoot is restarted, the same sessions will remain to be active.
If Peter wants this too, he needs to persist information needed to handle session timeouts.
So, the approaches are not so different.