Re: A DBA philosopical question

From: DA Morgan <damorgan_at_psoug.org>
Date: Wed, 07 Dec 2005 15:54:00 -0800
Message-ID: <1133999640.305451@jetspin.drizzle.com>

Joel Garry wrote:

>>What people that defend RAID 5 can not do, however, is repeal the laws
>>of physics. Parity calculations and 200%+ more writes can not be free.

>
>
> The trick with dealing with the laws of physics is to avoid the ones
> that penalize you. Hydrogen power is much more efficient than
> gasoline, but what do you put in the Jag?

Petrol to be sure. But then the laws of physics dictate that gasoline has a higher concentration of hydrogen than does the compressed gas.

> I hate defending RAID 5. If it were up to me it would be BAARF all the
> way. But no one pays for it to be up to me. The important thing
> is... it works for some sets of problems. Where it doesn't work is a
> much more powerful argument against it.

Well we should certainly not contribute to a new mythology that says "RAID5 is always bad." But before one starts implementing it under an Oracle database one should approach from the side of skepticism ... not optimism. As with everything else ... test your assumptions.

-- 
Daniel A. Morgan
http://www.psoug.org
damorgan_at_x.washington.edu
(replace x with u to respond)

Received on Wed Dec 07 2005 - 17:54:00 CST