通常，诊断事件可以在Session级设置，也可以在系统级设置，如果你要诊断全局错误，则最好在系统级设置较为盒式，下面是一个测试实例，仅供大家参考:

以下为引用的内容：
SQL> alter system set event='984 trace name ERRORSTACK level  10' scope=spfile;
System altered.
SQL> startup force;
ORACLE instance started.
Total System Global Area  101782828 bytes
Fixed Size                   451884 bytes
Variable Size              37748736 bytes
Database Buffers           62914560 bytes
Redo Buffers                 667648 bytes
Database mounted.
Database opened.
SQL> create table t (name varchar2(10),id number);
Table created.
SQL> insert into t values(a,1);
insert into t values(a,1)
                    *
ERROR at line 1:
ORA-00984: column not allowed here
SQL> !

请注意，此刻984错误将会被跟踪，记录到跟踪文件中。注意检查udump目录，找到trace文件:

注释：此跟踪文件可以定位和诊断错误。

以下为引用的内容：

[oracle@jumper oracle]$ cd $admin
[oracle@jumper udump]$ ls -sort
total 1020
   4 -rw-r--r--    1 oracle        533 Mar  2 16:06 t.sql
   4 -rw-r--r--    1 oracle        522 Mar  3 09:44 d.sql
  20 -rw-r--r--    1 oracle      17445 Mar  8 11:06 a.log
   4 -rw-r-----    1 oracle       3254 Mar 14 23:15 conner_ora_30683.trc
   4 -rw-r-----    1 oracle       1645 Mar 14 23:15 conner_ora_30701.trc
   4 -rw-r-----    1 oracle       1638 Mar 14 23:16 conner_ora_30719.trc
   4 -rw-r-----    1 oracle       1645 Mar 16 09:05 conner_ora_18565.trc
 976 -rw-r-----    1 oracle     993555 Mar 16 09:06 conner_ora_18589.trc
[oracle@jumper udump]$ vi conner_ora_18589.trc

/opt/oracle/admin/conner/udump/conner_ora_18589.trc
Oracle9i Enterprise Edition Release 9.2.0.4.0 - Production
With the Partitioning option
JServer Release 9.2.0.4.0 - Production
ORACLE_HOME = /opt/oracle/product/9.2.0
System name:    Linux
Node name:      jumper.hurray.com.cn
Release:        2.4.21-15.EL
Version:        #1 Thu Apr 22 00:27:41 EDT 2004
Machine:        i686
Instance name: conner
Redo thread mounted by this instance: 1
Oracle process number: 10
Unix process pid: 18589, image: oracle@jumper.hurray.com.cn (TNS V1-V3)
*** 2005-03-16 09:06:56.178
ksedmp: internal or fatal error
ORA-00984: column not allowed here
Current SQL statement for this session:
insert into t values(a,1)
----- Call Stack Trace -----
calling              call     entry                argument values in hex
location             type     point                (? means dubious value)
-------------------- -------- -------------------- ----------------------------
ksedmp()+269         call     ksedst()+0           0 ? 0 ? 0 ? 0 ? 922C89F ?
                                                   AA642A0 ?
ksddoa()+446         call     ksedmp()+0           A ? AABDCA8 ? B70100B0 ?
                                                   3D8 ? 1 ? B7010114 ?
ksdpcg()+521         call     ksddoa()+0           B70100B0 ? AABDCA8 ?
ksdpec()+220         call     ksdpcg()+0           3D8 ? BFFF3D20 ? 1 ?
ksfpec()+133         call     ksdpec()+0           3D8 ? 3D8 ? AABAE7C ?
                                                   BFFF3D54 ? 9835E89 ?
                                                   AA642A0 ?
[oracle@jumper udump]$