Re: Max SGA size in 32 bit Oracle

Just a few general remarks.

As explained before increasing indiscriminately the SGA has it's tradeoffs. In many cases you will just create a different problem area.
Also: to gain that last 1 or 2 percent more, you need much much more resources. You always should consider whether you really need that Finally: If your application is firing 'random' sql, without using bind variables (in my experience: *all* jdbc applications) you can increase the sga and especially the shared pool what you want, but the hit ratio will remain at what it is: way too low.

Hth,

Sybrand Bakker, Oracle DBA

On 22 Feb 2001 05:21:04 GMT, xux_at_informa.bio.caltech.edu (Xuequn Xu) wrote:

>GC, does the same application run faster in 64-bit oracle than in 32-bit version?
>I wonder whether larger SGA can buy you improved performance or not... In my
>understanding, the same application will probably not speed up in 64-bit; what
>the huge SGA buys you is the larger number of concurrent connections (i.e. allowing
>more tasks to be done, but each task may not necessarily run faster than it
>would in 32-bit oracle). Is this true? Thanks.
>
>GC (assistant_madman_at_hotmail.com) wrote:
>: kipnukdog wrote:
>: >
>: > Sybrand, thanks.
>: > I understand the guidelines, but is it possible, say on a 16GB Memory machine
>: > would you be able to allocate more than 2.5 GB to the SGA? (we have some very
>: > large buffer_pool_keep requirements) I have read on a 32 bit Oracle
>: > installation, 1.74GB is max, unless you remap the SGA in the kernel, and then
>: > you are allowed up to 2.5GB.
 

>: If you are running 64-bit, then yes, you can have a larger SGA than
>: 2.5GB (we have a db with about 8GB sga).
>: If it's 32-bit, then no, you are stuck with the 2.5GB limitation.
 

>: Cheers,
>: GC
Received on Thu Feb 22 2001 - 00:19:35 CST