Yeah, that's a common situation. Wish you luck with the tweaking. Certainly if I were in your situation, I would collect and assemble a case using all metrics regarding buffer usage, dictionary latching , etc, due to this huge hist_head$. regards, alvaro >But, while that's going on, I'd like to see what I can do and when I >came across HIST_HEAD$ apparently having pockets of free space, I >thought I'd go down that road, especially since this could be impacting >others as well. Dave -- http://www.freelists.org/webpage/oracle-l