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Re: RE: should you seperate indexes from tables in seperate datafiles

From: <rgaffuri_at_cox.net>
Date: Tue, 15 Jul 2003 10:32:45 -0400
Message-Id: <25929.337811@fatcity.com>


does anyoen disagree? Didnt this get started with the 'DBA Handbook' or was it a different text?

>
> From: "Mercadante, Thomas F" <NDATFM_at_labor.state.ny.us>
> Date: 2003/07/15 Tue AM 11:10:05 EDT
> To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
> Subject: RE: should you seperate indexes from tables in seperate datafiles
>
> R,
>
> Some of it depends on the disk storage. I have always followed the
> time-proven method of organizing disks and placing indexes away from the
> tables they belong to.
>
> Our warehouse is using EMC external disk. What the warehouse architect did
> was to stripe the EMC disks in such a way that all mount points (Sun system)
> are spread across all the EMC disks. What this does is to spread all files
> in the database across all the EMC drives. And with 4 Gig of EMC cache
> available, it further disproves the theory that separing indexes from data
> are required. The end result, in my case, is almost like one big RAM disk -
> where all disk IO is spread across all disk.
>
> If you do not have this arrangement, then I would still try and keep indexes
> and data away from each other. But let's face it, we *never* have enough
> disk mount points, so we end up merging things together somewhat anyway.
>
> hope this helps.
>
> Tom Mercadante
> Oracle Certified Professional
>
>
> -----Original Message-----
> Sent: Tuesday, July 15, 2003 10:49 AM
> To: Multiple recipients of list ORACLE-L
>
>
> There has been alot of literature stating that you will recieve performance
> improvements by seperating indexes and tables across multiple I/O points.
>
> Ie... you have a tables tablespace and an index tablespace. If you put them
> on seperate hard drives, you will have less I/O contention.
>
> Now Im seeing some articles stating that this is not true. That oracle
> actually accesses indexes and tables serially. Now it might be useful
> seperate indexes from tables for maintenance purposes but this wont lower
> I/O contention.
>
> Can anyone chime in on this? Curious to see where the evidence is leading?
>
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.net
> --
> Author: <rgaffuri_at_cox.net
> INET: rgaffuri_at_cox.net
>
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> Author: Mercadante, Thomas F
> INET: NDATFM_at_labor.state.ny.us
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Received on Tue Jul 15 2003 - 09:32:45 CDT

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