Enabling Automatic Memory Management

If you did not enable automatic memory management when you installed and configured your database, then Oracle recommends that you do so after installation, unless you are an experienced DBA with specific reasons to manually tune memory sizes. With automatic memory management, the Oracle instance dynamically tunes all memory components to optimize performance as the workload changes.

To enable automatic memory management:

1. Go to the Database Home page, logging in as user SYS.

   See "Accessing the Database Home Page".

   Note: You must log in as user SYS to change the maximum memory size, which is a static initialization parameter.

2. At the top of the page, click Server.

   The Server subpage appears.

3. In the Database Configuration section, click Memory Advisors.

   The Memory Advisors page appears with the SGA subtab (in the middle of the page) displayed by default.

4. If the Maximum SGA Size field contains a positive number that is greater than or equal to the desired total amount of memory to allocate to the database, then skip to Step 10.

5. In the Maximum SGA Size (MB) field, enter the maximum permissible size for database memory.

   Use the sum of the current sizes of the SGA and instance PGA as a guideline, and optionally add some room for growth.

6. Click Apply.

   A confirmation page appears, indicating that you must restart the database.

7. Click Yes and follow the guided instructions to restart the database.

8. After you have initiated the database restart, wait a few minutes and then click Refresh.

   The Database Home page appears.

9. Return to the Memory Advisors page.

   You might need to log out and log back in to Enterprise Manager to get this page to display correctly after the database restart.

10. Next to Automatic Memory Management Disabled, click Enable.

    The Enable Automatic Memory Management page appears.

11. In the field titled Total Memory Size for Automatic Memory Management, enter the desired amount of memory to allocate to the database, and then click OK.

    A confirmation message appears.