You are the Database Administrator （DBA） of your company. You execute the following statement on an Oracle 10g instance： SQL> ALTER SYSTEM SWITCH LOGFILE； Which two tasks are performed when the statement is executed？ （）
- A The DBWn process writes to the datafile.
- B Changes in the background process are recorded.
- C The log file is updated with the current SCN number.
- D The System Change Number （SCN） is recorded in the control file.
- E The changes to the listener configuration in the listener.ora file are recorded.