Enabling or Disabling the Standard Audit Trail
Before you perform the standard auditing procedures described in this section, you must
enable standard auditing. When you enable standard auditing, you can create the audit trail in
the database audit trail or write the audit activities to an operating system file. If you write to an
operating system file, you can create the audit record in text or XML format.
To enable or disable the standard audit trail:  
    1. Start Database Control.
    2. Log in as SYS and connect with the SYSDBA privilege.
                  o User Name: SYS
                  o Password: Enter your password.
                  o Connect As: SYSDBA
    3. Click Server to display the Server subpage.
    4. In the Database Configuration section, click Initialization Parameters.
        The Initialization Parameters page appears.
    5. Click SPFile to display the SPFile subpage.
        If the SPFile tab does not display in your installation, then you did not install Oracle Database
        using a server parameters file. Go to the next step.
    6. In the Name field, enter audit_trail to find the AUDIT_TRAIL initialization parameter,
       and then click Go.
        You can enter the first few characters of the parameter, for example, AUDIT_. Alternatively,
        you can scroll down the list of parameters to find the AUDIT_TRAIL parameter.
    7. In the Value field, select one of the following values:
                 o DB: Enables database auditing and directs standard audit records to the database
                      audit trail (SYS.AUD$), except for records that are always written to the
                      operating system audit trail. (This value is the default if you created the database
                      using Database Configuration Assistant. Otherwise, the default is NONE.)
                 o OS: Enables database auditing and directs all audit records to an operating
                      system file. Writing the audit trail to operating system files is better for
                      performance instead of sending the audit records to the SYS.AUD$ table. If the
                      auditor is distinct from the database administrator, you must use the operating
                      system setting. Any auditing information stored in the database is viewable and
                      modifiable by the database administrator.
                       To specify the location of the operating system audit record file, set
                       the AUDIT_FILE_DEST initialization parameter. The first default directory
                       is $ORACLE_BASE/admin/$ORACLE_SID/adump.
                   o   NONE: Disables standard auditing.
                 o    DB, EXTENDED: Performs all actions of the AUDIT_TRAIL=DB setting and
                      also populates the SQL bind and SQL text CLOB-type columns of
                      the SYS.AUD$ table, when available. (These two columns are populated only
                      when this parameter is specified.)
                 o    XML: Writes to the operating system audit record file in XML format. Prints all
                      elements of the AuditRecord node (as specified by the by the XML schema
                      in http://xmlns.oracle.com/oracleas/schema/dbserver_auditt
                      rail-11_2.xsd XSD file) except Sql_Text and Sql_Bind to the operating
                      system XML audit file. This .xsd file represents the schema definition of the
                      XML audit file. An XML schema is a document written in the XML Schema
                      language.
                 o    EXTENDED: Specifies XML, EXTENDED, which performs all actions of XML and
                      also populates the SQL bind and SQL text CLOB-type columns of
                      the SYS.AUD$ table, wherever possible. (These columns are populated only
                      when this parameter is specified.)
       For a detailed explanation of the AUDIT_TRAIL initialization parameter settings, see Oracle
       Database Security Guide.
   8. Click Apply.
   9. Restart the Oracle Database instance:
                 o    Click the Database Instance link.
                 o    Click Home to display the Database Control home page.
                 o    Under General, click Shutdown.
                 o    In the Startup/Shutdown Credentials page, enter your credentials.
                      See Oracle Database 2 Day DBA for more information.
                 o    After the shutdown completes, click Startup.
Note the following:
      You do not need to restart the database if you change the auditing of objects. You only need to
       restart the database if you made a universal change, such as turning on or off all auditing or
       changing the destination of the audit trail operating system files.
      You do not need to set AUDIT_TRAIL to enable either fine-grained auditing or SYS auditing.
       (SYS auditing enables you to monitor the activities of a system administrator. See Oracle
       Database Security Guide for more information.) For fine-grained auditing, you add and remove
       fine-grained auditing policies as necessary, applying them to the specific operations or objects
       you want to monitor. You can use the AUDIT_SYS_OPERATIONS parameter to enable and
       disable SYS auditing.