Use the Dynamic SGA feature in 32-bit Oracle running on 64-bit Solaris?

From: <dominica_at_gmail.com>
Date: 2 Mar 2005 13:31:08 -0800
Message-ID: <1109799068.034294.100390@g14g2000cwa.googlegroups.com>

Hi All,

I have to compare 64 bit 9.2 versus 32 bit 9.2 to see what is the pros and cons for upgrading to which version for my work's production database.

My question is will I be able to use the Dynamic SGA feature in 32-bit Oracle running on 64-bit Solaris?

Let me tell you what happen?

I( my work) open a TAR on this topic, but the metalink analyst say one thing, and the oracle instructor say another thing?

Question for Metalink:
We are planning to upgrade from 8i to 9i and are interested in using the new
Dynamic SGA feature that is enabled by setting SGA_MAX_SIZE. However, I have
heard rumors that this feature is not available in 32-bit 9i if you have a
"large" SGA.

Could you please clarify this for me? I show below our current v$sga that
indiactes we are running a 3.3 gigabyte SGA now. Is this considered
"large"?

Would we need to upgrade to 64-bit 9i if we want to use dynamic SGA sizing with
an SGA of this size?
NAME VALUE

----------------------------------- ----------

Fixed Size 73888
Variable Size 1913102336
Database Buffers 1638400000
Redo Buffers 5259264

Oracle instructor said this:

My co-worker took a class from Oracle Education recently, and the instuctor
told me this: "It depends on the platform. As we discuss in our 'Managing Oracle on Linux' class, to implement an SGA greater than 1.7 GB and upto 2.7 GB on a machine with more than 4 GB of memory on Linux Advanced Server 2.1, one needs to follow some steps to implement a large SGA. It may not be applicable in your case. I would upgrade the database with db_cache_size and sga_max_size parameters to start using dynamic sga. Try it out!" This is the same instrutor who told me that a large SGA as described above for Linux would prevent the use of Dynamic SGA. But I am on a difefernt platform, 64-bit Solaris, and would like to have a better idea of what's possible before I just go try it as suggested by the instructor.

Metalink said this:

Hi,

I did not find anything specific about limitations with dynamic SGA on 32bit oracle. However, you are already very near the max sga all owable anyway. I don't think that you can make it grow much bigger to take full
advantage of this feature.

Your best bet would be to use the 64bit oracle where the address space limits are much higher and you can really grow the SGA.

Oracle Analyst

My final question is:
So my
question is will I be able to use the Dynamic SGA feature in 32- bit Oracle running on 64-bit Solaris?

Thanks in advance,

Dominica Received on Wed Mar 02 2005 - 15:31:08 CST