Re^2: OT: What Hardware is important for large I/O bound processes

I agree completely with this; the hardware part is the final piecec to the puzzle.

We've tunined the SQL and other processes as much as possible. The performance we're getting matches our collective experience. It still impresses me how changes to the SQL can cut processes from days to a few minutes.

We're not finding more places to tune unless we partition the tables, which will be an interesting experiment. Your comment about the SANs in organizations struck a cord with me.

The standard process at the company is to take a SAN and format it to work like a single disk or LUN. The IS group claims their's no benefit to keeping things in individual disks since the SAN's cache will handle it. I've long had doubts on this. Do the v$ tables show the hotspots even on a single SAN disk?

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Re^3: OT: What Hardware is important for large I/O bound processes by astroboy (Chaplain) on Jul 28, 2005 at 20:24 UTC
Do the v$ tables show the hotspots even on a single SAN disk? Not really. Oracle has no idea about the disk abstration behind the scenes, and that is the problem - how do you match an Oracle datafile to the disks in the SAN? One of my mates had a huge SAN performance issue at a large site in the UK. They had all the SAN vendor's leading experts working on the problem (even flew in the guru from the US), and everyone was scratching their heads. As a test they set the system up with a single Linux-based PC with dedicated disks. Under load tests it flew. Now I'm not saying that SANs are no good, but they add a huge level of complexity, and you need very sharp in how you architect your solution.	[reply]

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Re^3: OT: What Hardware is important for large I/O bound processes
by astroboy (Chaplain) on Jul 28, 2005 at 20:24 UTC

Do the v$ tables show the hotspots even on a single SAN disk?

Not really. Oracle has no idea about the disk abstration behind the scenes, and that is the problem - how do you match an Oracle datafile to the disks in the SAN?

One of my mates had a huge SAN performance issue at a large site in the UK. They had all the SAN vendor's leading experts working on the problem (even flew in the guru from the US), and everyone was scratching their heads. As a test they set the system up with a single Linux-based PC with dedicated disks. Under load tests it flew. Now I'm not saying that SANs are no good, but they add a huge level of complexity, and you need very sharp in how you architect your solution.

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