Oracle 閃回觸發器的bug

做了一個測試。SQL> create table test1 (cola varchar2(10) );表已建立。SQL> create table test2 (colb varchar2(10));表已建立。SQL> select * from test1;未選定行SQL> select * from test2;未選定行SQL> create or replace trigger trigger1
  2    before insert on test1
  3    for each row
  4  declare
  5  begin
  6    insert into test2(colb) values('trigger1');
  7  end trigger1;
  8  /觸發器已建立SQL> select object_name,object_id from user_objects where object_name in ('TRIGGER1','TEST1');OBJECT_NAME                                                                    
--------------------------------------------------------------------------------
 OBJECT_ID                                                                     
----------                                                                     
TEST1                                                                          
    101621                                                                     
                                                                               
TRIGGER1                                                                       
    101623                                                                     
                                                                                SQL> col object_name for a20
SQL> /OBJECT_NAME           OBJECT_ID                                                
-------------------- ----------                                                
TEST1                    101621                                                
TRIGGER1                 101623                                                 SQL> insert into test1(cola) values('no1');已建立 1 行。SQL> commit;提交完成。SQL> select * from test1;COLA                                                                           
--------------------                                                           
no1                                                                             SQL> select * from test2;COLB                                                                           
--------------------                                                           
trigger1                                                                        --到這裡，表現一切正常。下面開始刪除恢複。SQL> drop table test1;表已刪除。SQL> select object_name,object_id from user_objects
  2  where object_name in ('TRIGGER1','TEST1');未選定行--如果沒加purge選項，則兩者都被刪除到資源回收筒，雖然user_object視圖看不到，在底層表obj$中能看到。
SQL> flashback table TEST1 to before drop;閃回完成。SQL> select object_name,object_id from user_objects
  2  where object_name in ('TRIGGER1','TEST1');OBJECT_NAME           OBJECT_ID                                                
-------------------- ----------                                                
TEST1                    101621                                                 --閃回成功後，www.bkjia.com在視圖中，正常對象只能看到表TEST1，不能看到觸發器。SQL> grant select on obj$ to ncoadev;授權成功。--切換到sys使用者，授權訪問指定對象。SQL> select name,obj# from sys.obj$ where obj# in (101621,101623);NAME                                                               OBJ#        
------------------------------------------------------------ ----------        
TEST1                                                            101621        
BIN$mlTKEo1FAGjgQ38AAAEAaA==$0                                   101623         --obj$表中，能看到 ID為101623的觸發器還在，但名字被Oracle打了內部標記。此時，用pl/sql dev等工具是看不到那個觸發器的。SQL> select * from test2;COLB                                                                           
--------------------                                                           
trigger1                                                                        SQL> insert into test1(cola) values('no2');已建立 1 行。SQL> commit;提交完成。SQL> select * from test2;COLB                                                                           
--------------------                                                           
trigger1                                                                       
trigger1     --又插入了一條記錄，證明觸發器還是生效的，但很難管理了。更麻煩的是後面：SQL> create or replace trigger trigger1
  2    before insert on test1
  3    for each row
  4  declare
  5  begin
  6    insert into test2(colb) values('trigger2');
  7  end trigger1;
  8  /觸發器已建立--如果開發人員看不到觸發器了，認為觸發器丟失，又建立了一個新的同名觸發器trigger1，仍然能建立。SQL> select * from test2;COLB                                                                           
--------------------                                                           
trigger1                                                                       
trigger1                                                                        SQL> insert into test1(cola) values('no3');已建立 1 行。SQL> commit;提交完成。SQL> select * from test2;COLB                                                                           
--------------------                                                           
trigger1                                                                       
trigger1                                                                       
trigger2                                                                       
trigger1     --此時，兩個觸發器都生效了，都作用在這個表上，會給系統帶來什麼影響呢？？    這算不算一個bug呢？