Re: Alter rollback segments

From: Daniel Morgan <damorgan_at_x.washington.edu>
Date: Thu, 12 Feb 2004 09:08:16 -0800
Message-ID: <1076605648.353638@yasure>

Patrik wrote:

> Daniel Morgan <damorgan_at_x.washington.edu> wrote in message news:<1076533861.884709_at_yasure>...
>

>>Patrik wrote:
>>
>>
>>>Hi,
>>>
>>>I want to add "alter rollback segments" and "set transaction use
>>>rollback..."
>>>in my otherwise functioning procedure. I have to control which
>>>rollbackseg that the proc uses when it updates due to very large
>>>transactions.
>>
>>Why?
>>
>>Every bit of 'good' advice from Tom Kyte and other experts indicates
>>that this is a bad idea. Just resize your rollback segments appropriately.
>>
>>And if you have 9i ... you shouldn't be using rollback segments at all

>
>
> The enviroment is Oracle 8.1.7 and OPS each node (2) has 20
> rollbacksegs that the main ERP-system and other smaller apps uses.
> What I'm doing is running special scripts and now procedures that is
> more heavy on rollbacksegs than usual. My idea is instead of
> increasing the size 40 rollbacksegs (we don't have that much diskspace
> anyway) I make 2 big rollbacksegs that is default offline and I use
> them only for this purpuse. I'm not an Oracle expert so I'm thankful
> for every bit of advice I get, but it seems to me that your suggestion
> wouldn't work in my case.
>
> /Patrik

What you are suggesting is exactly what Tom Kyte and the other experts say you should not do. There are copious amounts of material available on why it is a bad strategy so read Tom's books, search google, etc.

BTW if you have room for the two new big rollback segments you have room to resize the existing rollback segments. Reconsider how rollback segements work and look at the cost of a new 72GB disk. Surely your organization can afford a few hundred dollars.

-- 
Daniel Morgan
http://www.outreach.washington.edu/ext/certificates/oad/oad_crs.asp
http://www.outreach.washington.edu/ext/certificates/aoa/aoa_crs.asp
damorgan_at_x.washington.edu
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Received on Thu Feb 12 2004 - 11:08:16 CST