Re: maximum sga size for a given RAM

From: Sybrand Bakker <postbus_at_sybrandb.demon.nl>
Date: Wed, 2 May 2001 18:42:27 +0200
Message-ID: <tf0e3jh2f0rsca@beta-news.demon.nl>

"Richard Chen" <chenri_at_snet.net> wrote in message news:3AF00995.966E46AC_at_snet.net...
> I have the recollection that the size of sga should be no more than
> one third of the physical RAM. A search on google site also confirms
> my recollection:
>
>

http://groups.google.com/groups?q=oracle+sga+size+guideline+ram&hl=en&lr=&sa fe=o
>
> ff&rnum=1&ic=1&selm=lpe89tcmemeq3mnta64l5mbfnvj8e8rs45%404ax.com
>
> However, a recent magazine article recommends that 60% of physical RAM
> should be devoted to sga:
>
> http://www.sysadminmag.com/current/0105b/0105b.htm
>
> Does oracle8 changed things so that sga can be twice as large
> as before? Anyone know authoritive references on this?
>
> Thanks for any info.
>
> Richard
>

First of all: they don't give any rationale for this rule of thumb Secondly: I would definitely not make this 'rule of thumb' a generic guideline for all platforms. Everyone knows how much memory is available on NT after a fresh boot without Oracle. If you go for 60 % on NT you will have paging.

Regards,

Sybrand Bakker, Oracle DBA Received on Wed May 02 2001 - 11:42:27 CDT