Re: O 8.0.5 SGA size HPUX 11

"Dave Grantier" <dave_at_foobar.com> wrote in message news:3b33efb5.856141_at_news.mindspring.com...
> Greetings.
> I have been receiving some conflicting information and was hoping
> someone could shed some light on the issue.
>
> We have an Oracle 8.0.5 database (32 bit) running on an HPUX 11.0
> server (10 way CPU, 8 Gig RAM). I have been told that the maximum
> size for the SGA can be around 1.7 gigs or so, due to the 32 bit
> architecture of the database.
>
> Here's the part I don't follow:
> I have been also told that the sum of the SGA sizes of ALL INSTANCES
> running on the box must be under or at 1.7 gigs. This seems very
> strange to me. My thinking is that the HPUX kernel will assign a 4
> gig virtual address space (2 gig?) to each process in its process
> table. I'm not a unix programmer, so I can't confirm, though.
> It just seems like I should be able to crank up two or more databases,
> each with an SGA of 1.7 gigs if I wanted.
>
> I've been told it won't work.
>
> A: Could this be true? Have others seen it?
>
> B: If so, is this an Oracle thing? An HP thing?
>
> Any input would be greatly appreciated.
> Thanks,
> Dave
>
> +---------------------+---------------+
> |nojunkmail_at_nospam.com| bellsouth.net |
> |nospam_at_nojunkmail.com| davegrantier@ |
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Such move would just *force* paging on the O/S side, the operating word here being *virtual* memory.
There's a maximum as to what you can use before the O/S start paging out your precious SGA to disk (for all O/Ses the SGA is in *virtual* memory, so subject to paging). In the past Oracle advised not to use more than one third for SGA memory.

Hth,

Sybrand Bakker, Oracle DBA Received on Sat Jun 23 2001 - 00:20:45 CDT