Re: sga_max_size - pre-allocated at instance startup?

"Mladen Gogala" <gogala_at_sbcglobal.net> wrote in message news:pan.2006.03.04.03.21.40.53245_at_sbcglobal.net...
>
> Solaris has a perversion called "intimate shared memory, which
> allows processes to share page table as well as the page contents.
> From Oracle 7.3 all the way to 8i there was a parameter called
> "use_intimately_shared_memory", which was supposed to be set to true
> on Solaris. That parameter would enable Oracle to use XXX-shared
> memory and gain some performance. Another thing with which many
> vendors were toying was the post-wait pseudo device, which was
> faster then the semaphore operations. It was originally developed
> by SGI but I've seen it on AIX and Solaris as well.
> I do believe that Oracle was using classic shmget,shmat and similar
> calls wherever available and would switch to specialized libraries,
> based on parameters. Of course, I never worked for Oracle and I've
> never seen the source code, so I don't really know.
>
> --
> http://www.mgogala.com
>

Talking of intimate shared memory.

Your earlier comment about Solaris being the one Unix platform that doesn't allocate the entire memory on startup is, I believe, only true if you have MPT enabled ISM

-- 
Regards

Jonathan Lewis
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