Multiplexing the Online Redo Log

Oracle recommends that you multiplex the online redo log. Multiplexing provides better protection for data if an instance or media failure occurs.

To multiplex your online redo log, you must add members to each online redo log group. It is not required that online redo log groups be symmetrical, but Oracle recommends that your groups all have the same number of members. A database must have a minimum of two online redo log groups.

To multiplex the online redo log:

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 Storage section, click Redo Log Groups.

   The Redo Log Groups page appears.

4. Select a group and click Edit.

   The Edit Redo Log Group page appears.

5. Click Add.

   The Add Redo Log Member page appears.

6. If the Storage Type is set to File System, then in the File Name field, enter a file name for the new redo log member.

   For example, if your existing member file name is REDO01.log, then you might name this member REDO01a.log.

7. In the File Directory field, enter the directory where you want the data file to be stored on disk.

   You can create this file in the same directory as the other member of the redo log file group, but it is recommended that you store members on separate disk drives. That way, if there is a drive failure, then you still have access to one member.

8. Click Continue, and then click Apply to accept your changes.

   A confirmation message appears.

9. At the top of the page, click the Redo Log Groups link to return to the Redo Log Groups page.

10. Repeat Step 4 through Step 9 for every existing log group.