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Home -> Community -> Mailing Lists -> Oracle-L -> RE: "Never split index and data files ..."
It seems to me this is a debate about whether to separate tables from indexes at the hardware (RAID stripe) level, vs. doing it by placing them in different tablespaces, with the tablespaces located on separate devices.
Either way the indexes and the tables should not be on the same physical device, is this correct?
Now we can wonder - is Oracle faster at doing I/O when we are accessing indexes and tables in two separate tablespaces, or would the hardware RAID be faster when accessing stripes containing multiple physical devices.
Regards,
Patrice Boivin
Systems Analyst (Oracle Certified DBA)
Systems Admin & Operations | Admin. et Exploit. des systèmes Technology Services | Services technologiques Informatics Branch | Direction de l'informatique Maritimes Region, DFO | Région des Maritimes, MPO
E-Mail: boivinp_at_mar.dfo-mpo.gc.ca <mailto:boivinp_at_mar.dfo-mpo.gc.ca>
-----Original Message-----
From: Steve Adams [SMTP:steve.adams_at_ixora.com.au]
Sent: Friday, April 20, 2001 10:42 AM
To: Multiple recipients of list ORACLE-L
Subject: RE: "Never split index and data files ..."
Hi Allan,
Thanks for that reference. It is a much better treatment than the
Oracle paper
on the matter. The Oracle paper says "Stripe all files across all
disks using a
one megabyte stripe width". The Sun paper stops short of saying "all
... all"
which is a very significant difference. It says "As an extreme one
could take
every disk in the system, and stripe each table over every disk. In
practice, it
is more practical to break up all the disks into a few pools". It
also says,
"The database layout practice of keeping data and index separate is
still
useful, but using it for a first-order layout rule is a mistake."
This is
consistent with what I recommend in the series of tips on disk
configuration on
the Ixora web site.
@ Regards,
@ Steve Adams
@ http://www.ixora.com.au/
@ http://www.christianity.net.au/
-----Original Message-----
Sent: Friday, 20 April 2001 21:20
To: Multiple recipients of list ORACLE-L
There is also an article on Wide Thin Disk Striping at Sun Blue
prints
http://www.sun.com/software/solutions/blueprints/1000/layout.pdf
which expands on this philosophy.
Allan
>From: "Steve Adams" <steve.adams_at_ixora.com.au>
>Reply-To: ORACLE-L_at_fatcity.com
>To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
>Subject: RE: "Never split index and data files ..."
>Date: Thu, 19 Apr 2001 23:25:25 -0800
>
>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
Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
San Diego, California -- Public Internet access / Mailing
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-- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Boivin, Patrice J INET: BoivinP_at_mar.dfo-mpo.gc.ca 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).Received on Fri Apr 20 2001 - 11:58:20 CDT
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