select VALUE from V$OPTION 
where PARAMETER='Unified Auditing';

• Shutdown Database
• cd $ORACLE_HOME/rdbms/lib
• make -f ins_rdbms.mk uniaud_on ioracle
• set AUDIT_TRAIL = NONE, otherwise both auditing mechanisms will run concurrently
• Start Database

Records are written to the SGA queues and then periodically written to tables in the AUDSYS schema.
If it is required that the audit details are immediately written to the tables then …

BEGIN
 DBMS_AUDIT_MGMT.SET_AUDIT_TRAIL_PROPERTY (
  DBMS_AUDIT_MGMT.AUDIT_TRAIL_UNIFIED,
  DBMS_AUDIT_MGMT.AUDIT_TRAIL_WRITE_MODE,
  DBMS_AUDIT_MGMT.AUDIT_TRAIL_IMMEDIATE_WRITE);
END;

When the database is in READ ONLY mode then audit records are written to $ORACLE_BASE/audit/$ORACLE_SID
These files can then be later loaded into the database by …

BEGIN
 DBMS_AUDIT_MGMT.LOAD_UNIFIED_AUDIT_FILES;
END;

Create and enable an audit policy which will audit the creation of tables and sequences by user IAN.

CREATE AUDIT POLICY ian_audit_policy
  PRIVILEGES CREATE TABLE, CREATE SEQUENCE
  WHEN    'SYS_CONTEXT(''USERENV'', ''SESSION_USER'') = ''IAN'''
  EVALUATE PER SESSION
  CONTAINER = CURRENT;

AUDIT POLICY ian_audit_policy;

• ORA_SECURECONFIG (Enabled by default)
• ORA_DATABASE_PARAMETER
• ORA_ACCOUNT_MGMT