RE: Solaris 10 shmmax

Does it really matter if your shared memory is in one chunk or not? I seem to remember a bit of misinformation that used to float around was that if the SGA was not in a single shared memory chunk, then ISM was disabled. Turns out that isn't true. I can't think of any reason why it would be important for the SGA to be in one contiguous memory chunk.    

-Mark
 

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Mark J. Bobak
Senior Oracle Architect
ProQuest/CSA

"There are 10 types of people in the world: Those who understand binary, and those who don't."  

From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Kevin Closson Sent: Monday, March 26, 2007 1:09 PM
To: Hameed, Amir; ax.mount_at_GMAIL.COM; oracle-l_at_freelists.org Subject: RE: Solaris 10 shmmax

The 490 is a flat memory box and the Solaris port is smart enough to behave correctly.  

On the other hand, I have a lab server( Sun v490) running 10.2.0.2 on Solaris9. The shmmax is set to 20GB. My SGA is 12GB and I am seeing only one segment from ipcs. I have not tinkered with the NUMA optimization parameter. Per Metalink note 39926.1, multiple shared memory segments in 10gR2 are there for performance reason. Why is the behaviors of shared memory segments in 10gR2 is different on the same platform (v490 versus 6900)?                    

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http://www.freelists.org/webpage/oracle-l Received on Mon Mar 26 2007 - 13:05:08 CDT