Re: SSD on temp or undo tablespace

From: Kellyn Pot'vin <>
Date: Mon, 21 May 2012 17:32:06 -0700 (PDT)
Message-ID: <>

As a limited budget and $$ per MB is higher for SSD than for standard disk, I'm not sure how putting undo on SSD will be beneficial.  I would look into your undo retention settings and what is using your undo.  I have used SSD for Temp tablespace and seen great performance gains, but this was due to the design of the database requiring huge hash joins and sorts that would not fit within PGA allocated towards most given processes.  Is this what is happening in your environment? 

You really should take a full review of your database performance and find out what your waits are on.  If you aren't experiencing high waits for temp read and writes, then you are just wasting your money putting your temp tablespace on SSD.  If you are using AWR/ASH data, what are your top 5 waits on?

This would be my recommendation for a starting point...

Kellyn Pot'Vin
Senior Technical Consultant

 From: qihua wu <> To: oracle-l <> Sent: Monday, May 21, 2012 5:57 PM
Subject: SSD on temp or undo tablespace  

Hi experts,
We have limited budget, and put SSD for both undo and temp tablespace. We encountered ora-01555 error and some error that temp tablespace is not enough. I just want to know how SSD will be helpful for undo and temp tablespace. If temp on SSD has only limited benefit, we might assign all the SSD disk to undo, then use normal hard disk to temp. Did anyone have some suggestions

-- Received on Mon May 21 2012 - 19:32:06 CDT

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