甲骨文刪除和重建同義詞

Question

當我們使用CTAS這樣的：

create table big2 as select * from big1; 
drop table big1; 
rename big2 to big1; 

如果有同義詞現有的BIG1，我們需要對刪除並重新創建它們之前BIG1下降代名詞？或者這不是必要的？

Answer 1

不需要。別名同義詞是您爲對象提供的另一個名稱（無論是否在您的架構中）。請參閱下面的代碼。

（順便說一句，你不應該重命名錶T2直接點t1 ??請問你CTAS有其他有條件的地方，你在這裏沒有顯示？）

SQL> create table t1 as 
    2 select * from scott.emp; 

Table created. 

SQL> select count(*) from t1; 

    COUNT(*) 
---------- 
     14 

SQL> select count(*) from t2; 
select count(*) from t2 
        * 
ERROR at line 1: 
ORA-00942: table or view does not exist 


SQL> create synonym s1 for t1; 

Synonym created. 

SQL> create table t2 as 
    2 select * from t1; 

Table created. 

SQL> drop table t1; 

Table dropped. 

SQL> alter table t2 rename to t1; 

Table altered. 

SQL> select count(*) from t1; 

    COUNT(*) 
---------- 
     14 

SQL> select count(*) from s1; 

    COUNT(*) 
---------- 
     14