登入觸發器不生效，只在alert日誌中顯示

給一個登入觸發器不生效問題困擾半天，只在alert日誌中記錄，原來是有了DBA許可權。記錄下

TRIGGER AFTER LOGON ON DATABASE does not fire
Login as a user with DBA privileges
ORA-00604: error occurred at recursive SQL level %s
ORA-06512: at %sline %s

Oracel Database 11.2:

Oracle® Database PL/SQL Language Reference 11g Release 2 (11.2)
Chapter 9 PL/SQL Triggers
  Exception Handling in Triggers

In most cases, if a trigger runs a statement that raises an exception, and the exception is not handled by an exception handler, then the database rolls back the effects of both the trigger and its triggering statement.

In the following cases, the database rolls back only the effects of the trigger, not the effects of the triggering statement (and logs the error in trace files and the alert log):

    The triggering event is either AFTER STARTUP ON DATABASE or BEFORE SHUTDOWN ON DATABASE.

    The triggering event is AFTER LOGON ON DATABASE and the user has the ADMINISTER DATABASE TRIGGER privilege.

    The triggering event is AFTER LOGON ON SCHEMA and the user either owns the schema or has the ALTER ANY TRIGGER privilege.