如何在Oracle中开发after serverror触发器？

我正在尝试将数据库中的所有错误记录到表中.因此,当用户sys i编写以下代码时:

CREATE TABLE servererror_log (
    error_datetime  TIMESTAMP,
    error_user      VARCHAR2(30),
    db_name         VARCHAR2(9),
    error_stack     VARCHAR2(2000),
    captured_sql    VARCHAR2(1000));
/
CREATE OR REPLACE TRIGGER log_server_errors
AFTER SERVERERROR
ON DATABASE
DECLARE
 captured_sql VARCHAR2(1000);
BEGIN
  SELECT q.sql_text
  INTO captured_sql
  FROM gv$sql q, gv$sql_cursor c, gv$session s
  WHERE s.audsid = audsid
  AND s.prev_sql_addr = q.address
  AND q.address = c.parent_handle;

  INSERT INTO servererror_log
  (error_datetime, error_user, db_name,
   error_stack, captured_sql)
  VALUES
  (systimestamp, sys.login_user, sys.database_name,
  dbms_utility.format_error_stack, captured_sql);
END log_server_errors;

但是,当我强制尝试从不存在的表中选择一个错误时,它不会在表中记录错误.

有没有办法检查触发器是否会触发？此外,我尝试创建一个测试表来插入那里,但它也不起作用,即使将触发器定义为自治事务并在触发器内提交.

谢谢,华金