Implementing Address Windowing Extensions (AWE) or VLM on Windows 32 bit Platforms

Purpose

To address the growing need for use of more memory on 32-Bit Windows platforms, and explain how AWE is implemented by Oracle on Windows.

Objectives

A common question on the Windows 2000/Windows 2003 platform revolves around how to take advantage of systems with more than 4 GB of RAM.
The 32-Bit process address space for any process on Windows equates to a total of 4GB of addressable RAM. Of this, by default, 2GB is reserved for the process itself, and 2GB for the kernel. On systems running either Windows 2000 Advanced Server, or Windows NT 4.0 Enterprise Edition, this ratio can be changed by adding the /3GB switch to the boot.ini, allowing a process to address 3GB and reserving 1GB for the kernel. However, the total addressable memory for a single process is still only 4GB.

Implementation Steps

1- Edit the Boot.ini file to enable memory larger than 3GB
multi(0)disk(0)rdisk(0)partition(1)\WINNT="Microsoft Windows 2003 Advanced Server" /3GB /PAE

2- Grant Lock Pages in Memory Operating System privilege to OS user who restarts the database (SYSTEM user)

3- Restart oracle database service from Computer Management

4- Disable SGA_TARGET usage
SQL> conn / as sysdba
SQL> alter system set sga_target=0;

5- Set SGA_MAX_SIZE with any value just to start the database
SQL> alter system set sga_max_size=500M scope=spfile;

6- Restart the database
SQL> shutdown immediate
SQL> startup

7- Set the parameter USE_INDIRECT_DATA_BUFFERS to TRUE
SQL> alter system set USE_INDIRECT_DATA_BUFFERS=TRUE scope=spfile;

8- Create Pfile from SPfile
SQL> create pfile='d:\pfile_bkp.ora' from spfile;

9- Shutdown the database
SQL> shutdown immediate

10- Edit the new Pfile -->pfile_bkp.ora
- remove all parameters started with xlp. In the top of the Pfile
- remove SGA_MAX_SIZE parameter
- add DB_BLOCK_BUFFERS parameter ---->DB_BLOCKS x DB_BLOCK_SIZE--> (2*1024*1024*1024* 8192)
Where DB_BLOCK_SIZE the value above the 4 GB here we have 2 GB as the total server RAM is 6 GB

11- Startup the database with the previously created Pfile
SQL> startup pfile='d:\pfile_bkp.ora'

12- Create SPfile from the running Pfile
SQL> create spfile='d:\spfile_bkp.ora' from pfile='d:\pfile_bkp.ora';

13- Restart the database with the SPfile
SQL> shutdown immediate
SQL> startup

14- Alter values for pga_aggregate_target , shared_pool_size parameters in the SPfile
SQL> alter system set pga_aggregate_target=512M scope=both;
SQL> alter system set shared_pool_size=512M scope=both;
SQL> alter system set large_pool_size=64M scope=both;