OceanBase FLASHBACK TABLE BEFORE DROP
描述
用于从回收站中恢复被删除的表。
前置条件
回收站需要处于开启状态，可以通过SHOW VARIABLES LIKE 'recyclebin';来查看回收站是否开启。
obclient>SHOW VARIABLES LIKE 'recyclebin';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| recyclebin | ON |
+---------------+-------+
1 row in set (0.00 sec)如果回收站处于关闭状态，可以通过SET RECYCLEBIN = ON;来开启。回收站中的表没有被实际删除，仍然会占用资源，如果需要彻底删除，可以执行PURGE RECYCLEBIN;
格式
FLASHBACK TABLE object_name TO BEFORE DROP [RENAME to db_name.table_name];参数解释
|
参数 |
描述 |
|---|---|
|
object_name |
指定要恢复的对象名称或表名，只有在表所在的数据库中才能执行。恢复表时，也会同步恢复和表相关的索引。 |
|
RENAME to |
修改表名和表所属的库。 |
示例
- 从回收站中恢复被删除的表 t。
obclient>CREATE TABLE t(id INT PRIMARY KEY, k INT);
Query OK, 0 rows affected (0.04 sec)
obclient>INSERT INTO t VALUES(1,1);
Query OK, 1 row affected (0.00 sec)
obclient>SELECT * FROM t;
+----+------+
| id | k |
+----+------+
| 1 | 1 |
+----+------+
1 row in set (0.00 sec)
obclient>DROP TABLE t;
Query OK, 0 rows affected (0.01 sec)
obclient>SELECT * FROM t;
ORA-00942: table or view 'SYS.T' does not exist
obclient>SHOW RECYCLEBIN;
+--------------------------------+---------------+-------+----------------------------+
| OBJECT_NAME | ORIGINAL_NAME | TYPE | CREATETIME |
+--------------------------------+---------------+-------+----------------------------+
| RECYCLE_$_2_1616038871797032 | T | TABLE | 18-MAR-21 11.41.11.797691 AM|
+--------------------------------+---------------+-------+----------------------------+
1 row in set (0.00 sec)
obclient>FLASHBACK TABLE t TO BEFORE DROP;
Query OK, 0 rows affected (0.01 sec)
obclient>SELECT * FROM t;
+----+------+
| id | k |
+----+------+
| 1 | 1 |
+----+------+
1 row in set (0.00 sec)