RE: How to allocate >2GB to SGA

Amir, please forgive for opening this back up to the list.

Depends on the database block size. Remember that each buffer has metadata (chains, lru) in the variable component of the SGA. The more buffers, the more metadata. The variable component of the SGA has to fit in the address space of the process. The indirect buffers are accessed through a set of "windows panes" in the address space (the size of the "windows panes" can be increased with an environment variable up to 32MB if I recall). The variable component also has the shared pool, so a larger shared pool means less room for the buffers metadata.

Realistically, 8GB SGA is pretty reasonable to expect with indirect data buffers with 32Bit 10g and RHEL4 hugetlb.

But again, I'll state that it is pretty shaky. Given the state of 64bit these days, I can't imagine needing to play with this stuff.

-----Original Message-----

From: Hameed, Amir [mailto:Amir.Hameed_at_xerox.com] Sent: Tuesday, January 16, 2007 11:50 AM To: kevinc_at_polyserve.com
Subject: RE: How to allocate >2GB to SGA

Kevin,
On a 32-bit OS and 32-bit Oracle, how much larger an SGA can be?

-----Original Message-----

From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Kevin Closson Sent: Tuesday, January 16, 2007 2:44 PM
To: Harvinder.Singh_at_MetraTech.com; Don Seiler Cc: oracle-l
Subject: RE: How to allocate >2GB to SGA

--
http://www.freelists.org/webpage/oracle-l