To roll back datafiles to a Storage Checkpoint

1. Verify that the datafile to which you want to roll back is offline.

2. Access the Rollback a Storage Checkpoint wizard.

   See Accessing Storage Checkpoint tasks in the Java GUI.

   See Accessing database tasks in the Web GUI.

3. If the database is online, you will receive a prompt asking you if you want to continue. Click Yes to continue the Storage Rollback.

4. In the Rollback a Storage Checkpoint wizard, verify that you are rolling back to the correct Storage Checkpoint and click Next to continue. If you selected the wrong Storage Checkpoint, click Cancel. The information on this screen is read-only.

5. On the second screen, use the drop-down menu to select the appropriate buffer size in the Rollback Buffer Size field. The default buffer size is 128K.

   The buffer size configured for reads and writes when performing a Storage Rollback can affect performance. Vary the size to determine the optimal setting for your system.

6. Use the drop-down menu to select the appropriate number of threads in the Number of Threads field. The default number of threads is four.

   Depending on the number of CPUs available on your system and the type of volume on which the file system is located, this default setting may specify too few or too many threads.

7. Click the Roll back a Datafile button to indicate that you are rolling back the datafile to the Storage Checkpoint.

8. Click Next to continue.

9. Select the datafile, or datafiles, you would like to roll back by clicking on the appropriate checkbox in the Datafile list.

10. Click Roll Back to continue.

11. If the Storage Rollback was successful, a confirmation message displays. Click OK to continue. You are then returned to the rollback window.

12. Perform any necessary Oracle media recovery.

13. Put the recovered datafile back online.