flashback table

前提：开启回收站

　　　查看回收站状态

SQL> show parameter recyclebin;

NAME				     TYPE	 VALUE
------------------------------------ ----------- ------------------------------
recyclebin			     string	 ON

　　

SQL> desc test;
 Name					   Null?    Type
 ----------------------------------------- -------- ----------------------------
 TABLE_NAME				   NOT NULL VARCHAR2(30)
SQL> drop table test;

Table dropped.
SQL> select original_name,operation,droptime from recyclebin;
no rows selected
SQL> flashback table test to before drop;
flashback table test to before drop
*
ERROR at line 1:
ORA-38305: object not in RECYCLE BIN
SQL> 

　　

SQL> show user
USER is "SYS"
SQL> 

　奇怪，为什么回收站是开的，删除时不进回收站呢？系统表空间是不放入回收站的

scott用户就没有问题：

SQL> show user
USER is "SCOTT"
SQL>create table  test as select * from emp;
Table created.

SQL> select count(1) from test;

  COUNT(1)
----------
       270

SQL> drop table test;

Table dropped.

SQL> select original_name,operation,droptime from recyclebin;

ORIGINAL_NAME			 OPERATION DROPTIME
-------------------------------- --------- -------------------
TEST				 DROP	   2019-09-11:02:13:37

SQL> flashback table test to before drop;

Flashback complete.

SQL> select count(1) from test;

  COUNT(1)
----------
       270

SQL> 

　回收站开启的方法：

alter session set recyclebin=off;

alter system set recyclebin=off DEFERRED;