为了调查Oracle 的故障，可以通过设置event ,来了解详细的状况。方法如下：

■ 如果使用 SPFILE,

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To enable it:

1. Check the current event setting status:

SQL> show parameter event;

2. Add an event and set it up:

If there is no existing event, it is set as follows:
SQL> alter system set event = '235 errorstack (3) systemstate (10)' scope = spfile;

If there is an existing event, add it and set it as follows:
For example, if there is already an event of "902 errorstack (3) systemstate (10)" as a result of the above "1"
SQL> alter system set event = '902 errorstack (3) systemstate (10): 235 errorstack (3) systemstate (10)' scope = spfile;

3. Just to be sure, I will get a backup of SPFILE:

Example of execution:
SQL> create pfile = '/ home / oracle / pfile.ora' from spfile;

4. Restart the database.

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To disable it:

1. Delete event 235:

If there is no existing event, it is set as follows:
SQL> alter system set event = '' scope = spfile;

If there is an existing event, restore the original value:
For example, if there is already an event "902 errorstack (3) systemstate (10)" before this event setting,
SQL> alter system set event = '902 errorstack (3) systemstate (10)' scope = spfile;

2. Restart the database.

■ 如果使用 PFILE,

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To enable it:

1. Check the line related to "*. Event" with the cat command in the contents of PFILE.

2. Add and configure event 235:

If there is no existing event, please modify it as follows:
*. Event = '235 errorstack (3) systemstate (10)'

The existing event will be appended and set as follows:
For example, if the event of *. Event = '902 errorstack (3) systemstate (10)' already exists as a result of the above "1"
In some cases,
*. Event = '902 errorstack (3) systemstate (10): 235 errorstack (3) systemstate (10)'

3. Restart the database.

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To disable it:

1. Correct the line related to "*. Event" to the contents of PFILE.

If there is no existing event, it is set as follows:

*. Event = ''

If there is an existing event, restore the original value:
For example,
if there is already an event of *. Event = '902 errorstack (3) systemstate (10)' before this event setting,
leave it as following:

*. Event = '902 errorstack (3) systemstate (10)'

2. Restart the database.

至于数据库是使用了PFILE, 还是使用了SPFILE，可以通过查看如下的SQL文来看:

select * from v$spparameter where value is not null;

如果返回0行，则表明是使用了 spfile 启动的。