Hello Gurus, If two users say user1 connected to Node1 and user 2 connected t Node 2 want to update the same block at the same time. How does this works it works internally in RAC, could you please put some light on this please. -- Thanks & Regards Nilesh Oracle DBA (sqlplus "/as sysdba" is my world) "As our circle of knowledge expands, so does the circumference of darkness surrounding it."--Einstein "All men die, few men ever truly live" -- Braveheart "You can get help from teachers, but you are going to have to learn a lot by yourself, sitting alone in a room." --Dr. Seuss "Know me for what I do and for not what I am. Judge me for what I can do and not for what I have done."-Unknown "Don't walk in front of me, I may not follow. Don't walk behind me, I may not lead. Just walk beside me and be my friend."- Albert Camus "Never argue with an idiot. They drag you down to their level and then beat you with experience." - Unknown -- //www.freelists.org/webpage/oracle-l