Modifying Memory Settings – Automatic Shared Memory Management

Modifying memory settings for automatic shared memory management involves using the Memory Advisors page of Database Control to change the total SGA size. This section assumes that automatic memory management is disabled, that automatic shared memory management is enabled, and that the desired new value for the total SGA size does not exceed the current value for maximum SGA size.

To modify the total SGA memory size:

1. Go to the Database Home page.

   See "Accessing the Database Home Page".

2. At the top of the page, click Server to view the Server subpage.

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

   The Memory Advisors page appears. Scroll down to the SGA subpage.

4. In the Current Allocation section, do one of the following:

   • In the Total SGA Size (MB) field, enter a new total size for the SGA.

   • Click Advice to use the SGA Advisor to help you choose a new SGA size.

     The SGA Size Advice window opens.

     
     Description of the illustration mem_allocation_advice.gif
     
     

     Click a point on the curve to change the total SGA size. The new SGA size is displayed below the graph. Continue clicking the curve until the desired value is displayed, and then click OK.

     This example graph shows that at the current time, increasing the total SGA size is not expected to provide any gain in performance.

     Note: The settings on this page can be modified only if Automatic Memory Management is disabled.

5. If you chose to use the SGA Size Advisor, then click a point on the curve to change the total memory size. Otherwise, go to Step 7.

   The new size is displayed below the graph.

6. Continue clicking the curve until the desired value is displayed, then click OK.

   You are returned to the Memory Advisors page.

7. Click Apply.

   A confirmation message appears.