With modern storages, striping-and-mirroring, very large disk groups, large LUNs etc, all of that is irrelevant. On some storage architectures you have no way of knowing *which* disk your data is on, leave alone whether the data is on the inner tracks or the outer tracks. Any table's 1MB extent is most likely striped across multiple disks as well.
Hemant Hemant At 09:35 PM Tuesday, Jesse, Rich wrote:
It was a few years ago and therefore subject to updating, but I've typically seen the "80%" Rule. The idea being that a physical drive fills from the outer tracks, and the speed of the data bits as they fly by the heads slows as the inner tracks are approached (think of standing on the outer edge of a merry-go-round versus being in the middle of it). Somehow, the generic "80%" was settled on as a filling point past which the access speed of data on the inner tracks degrades "too much".
Hemant K Chitale http://web.singnet.com.sg/~hkchital