刚接管的新系统，想查看是否设置了某些事件，方法如下。

**APPLIES TO:**
Oracle Database - Enterprise Edition - Version 7.1.2.0 to 12.2.0.1 [Release 7.1.2 to 12.2]
Information in this document applies to any platform.

**GOAL：**
There are times when we need to disable or list out the existing oracle diagnostics events set on existing application or any existing Session. This note lists out a worked out example of how to capture existing session or system level diagnostics event set and how to disable them later on after verifying them.

<roidb01:orcl:/home/oracle>$sqlplus / as sysdba

SQL*Plus: Release 11.2.0.4.0 Production on Sat Feb 16 15:25:43 2019

Copyright (c) 1982, 2013, Oracle.  All rights reserved.

Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

SYS@orcl> oradebug setmypid
Statement processed.
SYS@orcl> oradebug eventdump system
Statement processed.
SYS@orcl> alter system set events='10231 trace name context forever,level 10';
System altered.

SYS@orcl> oradebug eventdump system 
10231 trace name context forever,level 10

SYS@orcl> alter system set events='10231 trace name context off';
System altered.

SYS@orcl> oradebug eventdump system
Statement processed.
SYS@orcl> 
SYS@orcl> alter session set events='10231 trace name context forever,level 10';
Session altered.

SYS@orcl> oradebug eventdump session
10231 trace name context forever,level 10
SYS@orcl> alter session set events='10231 trace name context off';
Session altered.
SYS@orcl> oradebug eventdump session
Statement processed.
SYS@orcl>