RE: The BIG picture - RE: Raw Devices v.s. File System

Hi Sean,

Regarding your comment about wanting to focus orders-of-magnitude gains, unless you have a form of Quick I/O (which simulates raw using a pseudo device driver layer) then the difference between even an advanced filesystem and raw can indeed be orders of magnitude.

Regards,
Steve Adams

http://www.ixora.com.au/
http://www.oreilly.com/catalog/orinternals/
http://www.christianity.net.au/


-----Original Message-----
From:	sean.hull_at_pobox.com [SMTP:sean.hull_at_pobox.com]
Sent:	Thursday, July 13, 2000 7:57 AM
To:	Multiple recipients of list ORACLE-L
Subject:	The BIG picture - RE: Raw Devices v.s. File System

On Wed, 12 Jul 2000, Gaja Krishna Vaidyanatha wrote:

> Given that the performance difference between these advanced
> fileystems and Raw is not that much, it really begs the issue as
> to why one would want to give up the benefits of a filesystem.

I think this derives from whether one can paint with a big brush so to speak, or if one gets stuck in the details. Tuning large complex computing systems, like Unix systems running Oracle, often requires one to be able to look at things from a "birds eye" perspective, and see the big picture. When you do this you realize that every little ounce of performance isn't what you're after, but the orders-of-magnitude gains. You get these from:

o using advanced filesystems over traditional buffered filesystems o tuning bad SQL queries
o making sure I/O is distributed across enough disks o making sure you have enough memory that you're not swapping

To name just a few. There are often incremental gains you can get from doing a VERY LOT OF EXTRA work, which are not worth it cost-wise, and headache-wise.

Just my $0.02.

Sean

--
Author:
  INET: sean.hull_at_pobox.com

Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051
San Diego, California        -- Public Internet access / Mailing Lists
--------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from).  You may
also send the HELP command for other information (like subscribing).