Serge Rielau wrote:

> Data placement IMHO falls into that category.

This is true, up to a limit. Spending time to try and isolate I/O
from tables/indexes/temp/etc. is one thing. But understanding how
your data is laid out on a SAN is still very relevant.

I have seen small data warehouses absolutely CRAWL (constant 95%
I/O wait) when no one bothered to pay attention to how tablespaces,
filesystems and LUNs map to physical disks in a SAN. And this
happens a LOT.