RE: Implementing ADDRESS WINDOWING EXTENSIONS (AWE) for increased memory

From: David Grosser <>
Date: Fri, 8 Feb 2008 16:05:52 -0500
Message-ID: <BAY124-W42DA04A0FA8C82A886546FEE2F0@phx.gbl>

Thanks to everyone for their responses. I did finally get AWE to work properly. Here's how I did it on two servers with Windows 2003 Enterprise SP1 and 8GB of memory:  

I added the /PAE switch to c:\boot.ini and rebooted the server.

In regedit I added AWE_WINDOW_MEMORY to HKLM/software/oracle/KEY_homex. I set it to value 1288490190. This is 20% higher than the default of 1GB. The instance wouldn't start when AWE_WINDOW_MEMORY was set to the default.

Removed SGA_TARGET from spfile.


Added DB_BLOCK_BUFFERS=200000 to spfile. This works out to 3125 MB with my 16k block size.

If you look in your spfile when SGA_TARGET is set, at the top you'll see the dynamic values that Oracle has set to parameters like SHARED_POOL_SIZE, JAVA_POOL_SIZE, LARGE_POOL_SIZE, etc. I manually added these values to the spfile.  

Lessons Learned

One response early on suggested that you need to reboot the server if you get a memory error while trying to start the instance. Rebooting the server is not necessary. Stopping and then starting the windows service resets everything and allows you to try again. The instance won't start if your value for DB_BLOCK_BUFFERS is too low. Anything below the value you set for AWE_WINDOW_MEMORY is probably too low. AWE and 4GT can work together. You can use AWE to expand database block buffers and 4GT can be used to expand the rest of the SGA and the PGA. Make sure the server will restart with the /PAE switch before making any spfile or registry changes.  

Thanks again for everyones help.  

David GrosserDBANSTAR Electric and Gas

Date: Wed, 6 Feb 2008 14:44:19 -0800From: jkstill_at_gmail.comTo: davidg.oraclel_at_live.comSubject: Re: Implementing ADDRESS WINDOWING EXTENSIONS (AWE) for increased memoryCC: oracle-l_at_freelists.orgFrom the ML Note:The size of this window is defined by a registry setting in the HOME key for     Oracle (HKLM\Software\Oracle\Homex) called AWE_WINDOW_MEMORY.  By default, 
    this value is 1GB, so if this value is not set in the registry,      AWE_WINDOW_MEMORY will be 1GB.  This is set on a per instance basis.
On Feb 1, 2008 1:22 PM, David Grosser <> wrote:

Hi, I'm trying to implement ADDRESS WINDOWING EXTENSIONS (AWE) to take advantage of all of the memory on my server. The server details are: Windows server 2003 enterprise edition, 4 processors, 8 GB memory, Oracle I tried to implement awe according to metalink note 225349.1 but my instance is not coming up. I did the following:

added switches /PAE and /3GB to the boot.ini

removed sga_target from the spfile added USE_INDIRECT_DATA_BUFFERS=TRUE to the spfile

added DB_BLOCK_BUFFERS to the spfileThe error I get when I start the database is :ORA-27102: out of memoryOSD-00034: additional error informationO/S-Error: (OS 8) Not enough storage is available to process this command. I've tried raising and lowering the memory but nothing works. Has anyone implemented AWE? If so, how did you get it to work? Thanks,David GrosserDBANSTAR Electric and Gas

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Received on Fri Feb 08 2008 - 15:05:52 CST

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