Re: Need advice !!

Good performer is relative of course. It is just that it could be faster than it is given better hardware.

If that mattered to your management they'd buy it. Obviously what you have is sufficient.

To use your analog ... Both a Cesna prop plane and a Cesna business jet will get you from point A to point B. One performs better than the other if you care about time and scalability.

Daniel Morgan

Keith Boulton wrote:

> damorgan <dan.morgan_at_ci.seattle.wa.us> wrote in message
> news:3C5EC972.3CC91E93_at_ci.seattle.wa.us...
> > I won't flame you give the caveat that only 4 disks are available. But it
> > certainly will not be a good performer.
> >
> Define "good".
>
> We seem to be having a case of what I'm going to call "ferrari syndrome"
> here. A ferrari is a good performing car, but so is a ford fiesta if all
> you're doing is nipping to the shops.
>
> I have a data warehouse (more like a shed, it's only 3GB) on five (old) 18GB
> drives in RAID 5 on a twin 500MHz pentium II with 1 GB of RAM.
>
> It's rebuilt in its entirety every night in two stages. The first takes
> under 15 minutes. The second takes 30 minutes.
> If I could be bothered, I could probably reduce the each stage to < 10
> minutes.
>
> Interactive queries on the most detailed aggregate table (about 1/10 of the
> size of the raw data) generally take less than 1/3 of a second. Should that
> be an issue, I can use materialised views to reduce that to 1/50th of a
> second. Similar queries are used to drill down until at a given level of
> detail, the source transactions can be selected, generally taking < 10
> seconds to display.
>
> This is, I think, enough of a "good performer" to be more than acceptable
>
> Even if there was 10x the amount of data (ie 30GB), I believe I could
> maintain similar interactive query times and get the overnight update to run
> in < 4 hours. The issue actually becomes one of concurrent usage and
> effective caching.
>
> If there was 300GB of data then I would obviously have to think again, but
> then I would also have to have more disks in any case. We know the original
> poster has a datawarehouse that fits in less than 72GB.
>
> Also, I would take issue with your comment about redo logs not being RAID5.
> Given good coding, the load on redo logs for a datawarehouse should be
> negligible, so it doesn't matter where they go.
>
> Argumentatively yours
>
> Keith
Received on Mon Feb 04 2002 - 16:25:02 CST