good question. The short answer is: We know our data will grow. We want to do our current tasks in the future, so we want 10x performance and capacity. It is not clear how fast our data will grow, so we want to be sure to have some additional capacity available.
P.S.
I have openend a small suvey about SAN systems here:
Have you considered simply partitioning the tables?
--Jeff Moden
RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row. First step towards the paradigm shift of writing Set Based code: ________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.
Change is inevitable... Change for the better is not.