In the interests of improved performance, Oracle recommends that logging be turned off by default. If Support requests logging to investigate an issue, it can easily be turned on.
To turn logging off:
Go to: http://<server name>:7001/em
to open Enterprise Manager.
In the left pane of Oracle Enterprise Manager, select Business Intelligence, and then coreapplication.
In the right pane, click the Diagnostics tab, and then the Log Configurations tab to display the Log Performance options.
Under Log Levels, set each of these log levels to Off:
Click Activate Changes.
At the top of the screen, click Restart to Apply Recent Changes.
As a courtesy, ensure that the restart will not affect other users. When the server is rebooted, logging is turned off.
If you need to reset logging, repeat the procedure, but in step 4 set the desired logging to On.