Re: User datafiles and index on separate disks

From: Howard J. Rogers <howardjr2000_at_yahoo.com.au>
Date: Wed, 01 Oct 2003 06:16:37 +1000
Message-Id: <3f79e563$0$13656$afc38c87@news.optusnet.com.au>

Goran wrote:

>
> "Howard J. Rogers" <howardjr2000_at_yahoo.com.au> wrote in message
> news:3f793720$0$1691$afc38c87_at_news.optusnet.com.au...

>> Peter wrote:
>>
>> > Is it a must to place datafiles, undo segments and table index on
>> > separate disks? If not, what are the benefits of doing so?
>> >
>> > Thanks
>>
>>
>> Please go to www.google.com and search the archives there for a thread in
>> this very newsgroup called 'Oracle Myths'. A number of hits will appear,
>> but you want the one with about 149 posts in the thread.
>>
>> It *was* a very long-running argument.
>>
>> Short story: indexes and tables do not need to be separated for

> performance

>> reasons, but probably do for management convenience. Undo segments should

>
> This is not (always) true.
> Please try to perform few simple real-world measurements and you'll find
> out that *whatever* files (tablespaces) you separate between (physical)
> disks and no matter what you do with them, you'll always gain some (or
> significant) performance gain compared to the files on the same (physical)
> disk.
>
> Regards...

Undoubtedly true. But what has that got to do with separating indexes and tables simply *because* they are indexes and tables?

Of course you should use lots of hard disks. Of course you should separate things onto separate hard disks if they contend for I/O. I didn't say otherwise.

What I did say was, the idea that tables should be separate from indexes *just because* one is an index and one is a table, and you will then see performance improvements, is a silly, silly myth that should have died a very long time ago.

Regards
HJR Received on Tue Sep 30 2003 - 15:16:37 CDT