System - SDE 9.2 SP6, Oracle 10.2.0.4, Versioned geodatabase
I have several hundred records in my SDE_LOGFILES and several hundred thousand in my SDE_LOGFILE_DATA tables that have persisted even though I have no active SDE sessions. According to the user docs these records are supposed to be truncated when the SDE session disconnects.
Using DELETE won't free the high-water storage for those tables. You can either TRUNCATE or DROP them (they'll get recreated in either the default tablespace or according to DBTUNE storage rules). - V