I had to kill an session using TOAD. This came up as "session marked for kill". However this has been running for over 14 hours now. This is far more than it the process had been running (3-4 hours). It was executing a stored procedure which was basically inserting some records into a table. This still shows up as the current statement.
Im concearned that killing the o/s session may not clear up what is causing the issue.
The only thing that I can think of that might have effected this was that I made a precision change on a table that was used by the stored procedure, after I killed the session. I would have thought oracle would have obtained an exclusive lock on the table if it was rolling back transactions from that table.