客户只是应用端报出的错误，为了进一步定位，服务端需要开errorstack协助定位具体问题。
下面就以这个ORA-2289为例，示范下errorstack的使用方法。
--开启errorstack
alter system set events '2289 trace name errorstack level 3';
--关闭errorstack
alter system set events '2289 trace name errorstack off';
开启errorstack期间，模拟一个会话发生了ORA-02289的报错：
[oracle@bogon trace]$ sqlplus / as sysdba
SQL*Plus: Release 19.0.0.0.0 - Production on Wed Apr 26 22:00:21 2023
Version 19.16.0.0.0
Copyright (c 1982, 2022, Oracle. All rights reserved.
Connected to:
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.16.0.0.0
SQL> select s2.nextval from dual;
select s2.nextval from dual
*
ERROR at line 1:
ORA-02289: sequence does not exist
SQL> exit
在alert告警日志可以看到提示：
2023-04-26T22:00:27.300427+08:00
Errors in file /u01/app/oracle/diag/rdbms/demo/demo/trace/demo_ora_3435.trc:
ORA-02289: sequence does not exist
进而在trc文件中进一步查询具体报错的SQL信息等：
[oracle@bogon trace]$ vi demo_ora_3435.trc
...
17 *** 2023-04-26T22:00:27.300081+08:00 (CDB$ROOT(1
18 *** SESSION ID:(2548.56891 2023-04-26T22:00:27.300150+08:00
19 *** CLIENT ID:( 2023-04-26T22:00:27.300158+08:00
20 *** SERVICE NAME:(SYS$USERS 2023-04-26T22:00:27.300164+08:00
21 *** MODULE NAME:(sqlplus@bogon (TNS V1-V3 2023-04-26T22:00:27.300170+08:00
22 *** ACTION NAME:( 2023-04-26T22:00:27.300177+08:00
23 *** CLIENT DRIVER:(SQL*PLUS 2023-04-26T22:00:27.300182+08:00
24 *** CONTAINER ID:(1 2023-04-26T22:00:27.300189+08:00
25
26 dbkedDefDump(: Starting a non-incident diagnostic dump (flags=0x0, level=3, mask=0x0
27 ----- Error Stack Dump -----
28 <error barrier> at 0x7ffed8393280 placed dbkda.c@298
29 ORA-02289: sequence does not exist
30 ----- Current SQL Statement for this session (sql_id=c6bu1kcbt5z3f -----
31 select s2.nextval from dual
32
33 ----- Call Stack Trace -----
34 calling call entry argument values in hex
35 location type point (? means dubious value
36 -------------------- -------- -------------------- ----------------------------
37 ksedst1(+95 call kgdsdst( 7FFED83926E0 000000002
...
我这里模拟是直接查询了不存在的序列，但是报这个错误其实未必是数据库问题，可以在MOS多搜索下相关案例，也有程序配置问题导致的情况。