90 lines
2.3 KiB
Markdown
90 lines
2.3 KiB
Markdown
FLASHBACK DATABASE
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=======================================
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描述
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-----------
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用于从回收站中恢复被删除的DATABASE。
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前置条件
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-------------
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回收站需要处于开启状态，可以通过
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`show variables like 'recyclebin';`
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来查看回收站是否开启。
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```javascript
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OceanBase(admin@test)> show variables like 'recyclebin';
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+---------------+-------+
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| Variable_name | Value |
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+---------------+-------+
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| recyclebin | ON |
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+---------------+-------+
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1 row in set (0.00 sec)
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```
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果回收站处于关闭状态，可以通过
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`set recyclebin = on;`
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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
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`purge recyclebin;`
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格式
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-----------
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```javascript
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FLASHBACK DATABASE object_name TO BEFORE DROP [RENAME TO db_name];
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```
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参数解释
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-------------
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| **参数** | **解释** |
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|-------------|----------------------------------------------------------------------|
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| object_name | 指定要恢复的object名称，不支持指定DATABASE名称。恢复DATABASE时，也会将DATABASE下面的表、索引等都恢复出来。 |
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| RENAME to | 恢复时将DATABASE重命名。 |
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示例
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-----------
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* 从回收站中恢复删除的DATABASE。
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```javascript
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OceanBase(admin@test)> create database da;
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Query OK, 1 row affected (0.03 sec)
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OceanBase(admin@test)> drop database da;
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Query OK, 0 rows affected (0.04 sec)
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OceanBase(admin@test)> show recyclebin;
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+--------------------------------------------------+---------------+----------+----------------------------+
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| OBJECT_NAME | ORIGINAL_NAME | TYPE | CREATETIME |
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+--------------------------------------------------+---------------+----------+----------------------------+
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| __recycle_$_1_1099511628829_18446744073709551615 | da | DATABASE | 2017-10-20 17:36:15.838771 |
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+--------------------------------------------------+---------------+----------+----------------------------+
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1 row in set (0.02 sec)
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OceanBase(admin@test)> flashback database __recycle_$_1_1099511628829_18446744073709551615 to before drop;
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Query OK, 0 rows affected (0.03 sec)
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```
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