RE: RE: "Never split index and data files ..."

From: Mohan, Ross <MohanR_at_STARS-SMI.com>
Date: Fri, 20 Apr 2001 10:37:32 -0700
Message-ID: <F001.002EDF91.20010420101538@fatcity.com>

Long ago in a galaxy, far far away, I did a semi-SAME thing on a Sequent box. Everything but logs....four controllers, each with full four-channel fastwide SCSI. Software raid0+1 (not 1+0). Stripe width 128Kblocks, 64Kbytes.

Worked like a charm.

Sun came in to "blow away" the two generation old box and layout sometime later. (E5500 flavor, probably A5000 class controllers )

It still doesn't work as well.

Ross

btw, we did PQO on this box ( 10 CPU, 90/133 MHz pentiums -- yes, you read that right ) and it was like something out of a dream....oracle 723 then 734. So sweet.

<==>   -----Original Message-----
<==>   From: Haskins, Ed [mailto:Ed.Haskins_at_VerizonWireless.com]
<==>   Sent: Friday, April 20, 2001 1:26 PM
<==>   To: Multiple recipients of list ORACLE-L
<==>   Subject: RE: RE: "Never split index and data files ..."
<==>
<==>
<==>   Dick,
<==>
<==>   Don't take this the wrong way...it's NOT meant to be sarcastic:
<==>
<==>   You said "SAME is a great theory, but I can't and
<==>   haven't seen it perform
<==>   well in practice, yet."
<==>
<==>   My question to you: Have you seen it in practice at
<==>   all? An actual working
<==>   implementation?
<==>
<==>   For that matter; has ANYONE seen it implemented in a
<==>   production environment?
<==>   I'm sure it must be somewhere, but I'm curious if anyone
<==>   knows where.
<==>
<==>   This is a subject that I'm really into right
<==>   now...that's why I'm prodding a
<==>   bit!
<==>
<==>   Thanks,
<==>
<==>   Ed Haskins
<==>   Oracle DBA
<==>   Verizon Wireless
<==>
<==>
<==>
<==>   -----Original Message-----
<==>   Sent: Friday, April 20, 2001 12:46 PM
<==>   To: Multiple recipients of list ORACLE-L
<==>
<==>
<==>   Steve,
<==>

<==>       I heard about this SAME philosophy at the last

<==>   NorthEast Oracle Users
<==>   Group
<==>   meeting from a individual who works on the utilities for
<==>   Oracle in the New
<==>   England Development Office. Although we did not get
<==>   deeply into the
<==>   philosophy,
<==>   I'll agree that it is not the silver bullet, actually it
<==>   can become a
<==>   performance detractor. The individual who wrote the
<==>   paper for Oracle (Anjo
<==>   Kolk) is a LONG time Oracle person, actually wrote the
<==>   core of the kernel,
<==>   so I
<==>   believe he's probably writing from a purely theoretical
<==>   point of view. In
<==>   that
<==>   light what he's saying would be true, stripe & mirror
<==>   everything and
<==>   theoretically you should never have an io bottleneck.
<==>   BUT, many hardware
<==>   platforms don't handle mirroring very well unless your
<==>   using a disk array
<==>   like
<==>   EMC's. Now that handles the mirror internally so we've
<==>   alleviated that
<==>   problem,
<==>   but EMC likes to break their drives into 'hyper volumes'
<==>   so your stripping
<==>   may
<==>   or may not be across physical drives. Also your stripes
<==>   can still have the
<==>   bottle neck of the number of SCSI cards in the computer.

<==>    In any case taking

<==>   a
<==>   little time to insure that redo logs, archive logs,
<==>   indexes, and data are
<==>   all
<==>   REALLY spread out across devices is the only way to go.
<==>   SAME is a great
<==>   theory,
<==>   but I can't and haven't seen it perform well in practice, yet.
<==>
<==>   Dick Goulet
<==>
<==>   ____________________Reply Separator____________________
<==>   Author: "Steve Adams" <steve.adams_at_ixora.com.au>
<==>   Date:       4/19/2001 11:25 PM
<==>
<==>   Hi All,
<==>
<==>   The author (Anjo Kolk) is an advocate of SAME (stripe and mirror
<==>   everything).
<==>   The SAME philosophy is that "everything" should be
<==>   striped across all the
<==>   disks
<==>   available. Separating indexes from their tables is
<==>   contrary to that
<==>   philosophy.
<==>   I don't agree with it, but that's where he's coming from anyway.
<==>
<==>   @   Regards,
<==>   @   Steve Adams
<==>   @   http://www.ixora.com.au/
<==>   @   http://www.christianity.net.au/
<==>
<==>
<==>   -----Original Message-----
<==>   Sent: Friday, 20 April 2001 6:56
<==>   To: Multiple recipients of list ORACLE-L
<==>
<==>
<==>   Whoaaa, I sure hope someone can, because I have never
<==>   heard that before?
<==>   Kev
<==>
<==>   -----Original Message-----
<==>   Ghosalkar
<==>   Sent: Thursday, April 19, 2001 4:36 PM
<==>   To: Multiple recipients of list ORACLE-L
<==>
<==>
<==>   Guys,
<==>
<==>   i was checking my statspack report on oraperf and i came
<==>   across this
<==>   statement.
<==>
<==>   "Never split index and data files to different sets of disks."
<==>
<==>   can anyone xplain the logic behind this.
<==>
<==>   Thanks
<==>   Mandar
<==>
<==>   --
<==>   Please see the official ORACLE-L FAQ: http://www.orafaq.com
<==>   --
<==>   Author: Steve Adams

<==>     INET: steve.adams_at_ixora.com.au

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<==>   Author:

<==>     INET: dgoulet_at_vicr.com

<==>     INET: Ed.Haskins_at_VerizonWireless.com