create or replace directory trc  as 'E:\oracle\diag\rdbms\mydb\mysid\trace';

 查看是否创建成功

 select * from dba_directories;

  create table alert_log ( text varchar2(400) )

 organization external (

 type oracle_loader

 default directory trc

 access parameters (

 records delimited by newline

 nobadfile

nodiscardfile

 nologfile

 )

 location('mysid_ora_2772.trc')   这个文件要放在trc指定的目录下

 )

 reject limit unlimited

 select * from alert_log where rownum < 5;