--只需重启实例，不要重启数据库

09:58:09 sys@PTFDB> ALTER SYSTEM SET AUDIT_TRAIL=DB,EXTENDED SCOPE=SPFILE;

System altered.

Elapsed: 00:00:00.14
09:58:18 sys@PTFDB> show parameter audit

NAME     TYPE VALUE
------------------------------------ ----------- ------------------------------
audit_file_dest     string /u01/app/oracle/admin/ptfdb/ad
ump
audit_sys_operations     boolean TRUE
audit_syslog_level     string
audit_trail     string DB
09:58:57 sys@PTFDB> alter system set AUDIT_SYS_OPERATIONS=TRUE SCOPE=SPFILE;

System altered.

Elapsed: 00:00:00.02
09:59:03 sys@PTFDB> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
09:59:30 sys@PTFDB> startup
ORACLE instance started.

Total System Global Area 9420095488 bytes
Fixed Size    2236248 bytes
Variable Size 3925868712 bytes
Database Buffers 5469372416 bytes
Redo Buffers   22618112 bytes
Database mounted.
Database opened.
10:00:04 sys@PTFDB> show parameter audit

NAME     TYPE VALUE
------------------------------------ ----------- ------------------------------
audit_file_dest     string /u01/app/oracle/admin/ptfdb/ad
ump
audit_sys_operations     boolean TRUE
audit_syslog_level     string
audit_trail     string DB, EXTENDED