RE: 11gR2 smart flash cache

From: <Joel.Patterson_at_crowley.com>
Date: Thu, 13 Jan 2011 09:33:37 -0500
Message-ID: <C95D75DD2E01DD4D81124D104D317ACA16011CF6C6_at_JAXMSG01.crowley.com>

Yes, I am interested also. We are going to be getting hardware in next month, and it has SSD's or what someone called an 'oracle accelerator card' :).

So, if you have implemented this and have anything to share, let me know (like even appropriate docs).

Joel Patterson
Database Administrator
904 727-2546

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From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Zhu,Chao Sent: Wednesday, January 12, 2011 8:00 PM To: Jeremy Schneider
Cc: steve.harville_at_gmail.com; oracle-l Subject: Re: 11gR2 smart flash cache

Nobody using that second tier smart cache yet? We were thinking about doing a POC on that see how it works; hopefully reduce the load on SAN so SAN can support more IOPS for more database (by reduce the very IO intensive database's IOPS);

We plan to install a 300gb fusion IO card onto the host, and let it serve as the cache;

On Thu, Jan 13, 2011 at 6:35 AM, Jeremy Schneider <jeremy.schneider_at_ardentperf.com<mailto:jeremy.schneider_at_ardentperf.com>> wrote: One quick note on this... direct reads do not always indicate temp (or even parallel). In 11g Oracle will sometimes start using direct path reads for serial full tablescans.

I recently observed this happening a lot with one of my clients. FYI, I believe that this particular database had an underconfigured SGA... might be related. Interestingly, because Oracle was doing so many FTS with direct path, the BCHR looked deceptively healthy.

-Jeremy

Steve Harville wrote:
> I have not tried this setting but I do have some experience with
> Oracle on flash drives.
> We are an EMC shop so most I/O is already cached (all writes and all
> sequential reads). The system cannot cache random reads so that is
> where I use flash drives. The temp tablespace can benefit the most
> from flash drives since it exhibits this read pattern. If "direct
> reads" are a large part of your total wait time then you can probably
> benefit from moving temp to flash.
>
> Steve Harville
>
> http://www.linkedin.com/in/steveharville
>
>
>
> On Wed, Jan 12, 2011 at 5:24 AM, Zhu,Chao <zhuchao_at_gmail.com<mailto:zhuchao_at_gmail.com>> wrote:
>
>> hi, List friends,
>> Oracle has been promoting this flash cache as second tier cache for
>> oracle for a while; Just wondering whether anyone has used this within the
>> industry?
>> We typically have 30gb-60gb SGA supporting 1TB-4TB database; We found
>> usually 30gb or 60gb cache size does not really matter much for majority of
>> our database(some has big diff though, depends on workload profile/active
>> dataset); But a 300gb flashdisk might make huge difference, and help reduce
>> the IOPS load on the SAN side?
>>
>> Looking forward to industry experience;
>>
>> Thx
>>
>>
>>
>> --
>> Regards
>> Zhu Chao
>>

--
http://www.ardentperf.com
+1 312-725-9249

Jeremy Schneider
Chicago



--
Regards
Zhu Chao


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Received on Thu Jan 13 2011 - 08:33:37 CST