The 50-60% range is the safe area for almost all people. I think this based on the following:
-- Number of concurrent users (around 10K per session)
-- Sort are size (init.ora and whatever is used)
-- OS paging/swapping thresholds (OS and RAM specific)
-- SGA size (init.ora)
I might be missing somethings, but I think that this is the bulk of it. The 50-60% range has existed for a while and 64bit systems are just starting to take off. So, I would guess with a 64bit systems with large amounts of RAM, let say 20GB, using 75% of it is not a bad thing. Also, on Unix machines the paging and swapping parameters can be adjusted to be much lower. But, setting them to low can cause the system to panic, when it needs RAM the most.
______________________ Applications come and go,
but the data remains!