Vivek, I was tempted to say "it will be covered in my next book" or "it depends". Jokes apart, there is an element of truth to what I said above, since the topics you raise are so broad with so many variables riddled with competing priorities; most scalability exercices I have participated in, are governed by technology, budgets, and needs (SLAs if you will) and the answers are seldom time invariant. I would think that in this forum you are likely to get an answer that would help you, if your questions are bit more pointed and specific to an aspect of the issue you are dealing with. My $02 -Krish -- //www.freelists.org/webpage/oracle-l