sql - 回滚已提交的事务

Question

有什么方法可以在rollback中执行oracle 11g提交的事务

我在db中做了一个delete from table并提交了它，现在我想rollback提交更改。有什么办法吗？

Answer 1

您无法回滚已提交的内容。在这种特定情况下，作为最快的选项之一，您可以做的是对已从中删除行并将其插入的表进行闪回查询。这是一个简单的示例：

注意：此操作的成功取决于undo_retention参数的值（默认为900秒）-一段时间（可以自动减少），在此期间撤消信息将保留在撤消表空间中。

/* our test table */
create table test_tb(
   col number
);
/* populate test table with some sample data */
insert into test_tb(col)
   select level
     from dual
  connect by level <= 2;

select * from test_tb;

COL
----------
         1
         2
/* delete everything from the test table */    
delete from test_tb;

select * from test_tb;

no rows selected

向后插入已删除的行：

/* flashback query to see contents of the test table 
  as of specific point in time in the past */ 
select *                                   /* specify past time */
  from test_tb as of timestamp timestamp '2013-11-08 10:54:00'

COL
----------
         1
         2
/* insert deleted rows */
insert into test_tb
   select *                                 /* specify past time */  
    from test_tb as of timestamp timestamp '2013-11-08 10:54:00'
   minus
   select *
     from test_tb


 select *
   from test_tb;

  COL
  ----------
          1
          2