Oracle恢复被删表的索引/约束

最近逛AskTom，遇到一个不错的提问：

Q：通过Flashback技术如何恢复被删表的索引及约束？

来看看Tom 大神的回答：

A：其实在使用Flashback恢复被删表的同时，其indexes和constraints也被恢复了，只不过名字变为了一BIN$开头的一串随机字符，因为其保留了再recycle bin表中的名字。

我们要做的就是重新命名丢失的索引和约束名。

原文：The indexes and constraints are actually restored by flashback, but you might not have recognized them.

They retain their recycle bin names，so their names start with BIN$ followed by seemingly random characters.

They come back with the table, but their names are lost. All you need to do is rename them.

For example:

alter index "BIN$/y02LoFDTm0bx1GIQtwx0A==$0"

rename to PK_SR_TEST1;

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Let's  begin with an example：

1、创建测试表 t：

SCOTT@orcl> create table t  2         ( x int,  3            constraint t_pk primary key(x),  4            constraint check_x check(x > 0)  5         );表已创建。

2、记录indexes 和 costraints存在时的SCN：

注意：此处需要给scott授予 dbms_flashback包执行权限，以sys登录：

SYS@orcl> grant execute on dbms_flashback to scott;

SCOTT@orcl> column SCN new_val SSCOTT@orcl> select dbms_flashback.get_system_change_number SCN from dual;       SCN----------  11394151

3、drop表 t，并进行闪回操作：

SCOTT@orcl> drop table t;表已删除。SCOTT@orcl> flashback table t to before drop;闪回完成。

此时，查询可见：恢复后的索引变为：BIN$xxxxx.

SCOTT@orcl> column index_name new_val ISCOTT@orcl> select index_name  2          from user_indexes  3         where table_name = 'T';INDEX_NAME------------------------------BIN$vk2xLfpbThSjwsdflA1WjQ==$0

4、现在授予scott用户闪回查询视图USER_INDEXES和USER_CONSTRAINTS权限并执行闪回查询，找到删除前的索引及约束名：

SCOTT@orcl> conn / as sysdba已连接。SYS@orcl> grant flashback on user_indexes to scott;授权成功。SYS@orcl> grant flashback on user_constraints to scott;授权成功。

SYS@orcl> conn scott/tiger已连接。SCOTT@orcl> column index_name new_val OISCOTT@orcl> select index_name  2         from user_indexes as of scn &S  3         where table_name = 'T';原值    2:        from user_indexes as of scn &S新值    2:        from user_indexes as of scn   11394151INDEX_NAME------------------------------T_PK

5、将索引名改回原值：

SCOTT@orcl> alter index "&I" rename to "&OI";原值    1: alter index "&I" rename to "&OI"新值    1: alter index "BIN$vk2xLfpbThSjwsdflA1WjQ==$0" rename to "T_PK"索引已更改。

6、修改约束方法一致，此处不再赘述。附上以上操作相关效果图：

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Present  By  Dylan.