Oracle基于时间点的恢复能够精确到什么样的精度? 以下测试用于进行一点说明。 1.首先做好冷备份 SQL*Plus: Release 9.2.0.6.0 - Production on Mon Jan 17 11:56:43 2005 Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved. Connected to an idle instance. 11:56:44 SQL> startup Total System Global Area 101785428 bytes 11:57:01 SQL> create table test (name varchar2(20)); Table created. Elapsed: 00:00:00.04 1 row created. Elapsed: 00:00:00.00 1 row created. Elapsed: 00:00:00.00 1 row created. Elapsed: 00:00:00.00 Commit complete. Elapsed: 00:00:00.00 11:57:29 SQL> drop table test; Table dropped. Elapsed: 00:00:00.07 3.恢复备份数据 D:\>sqlplus "/ as sysdba" SQL*Plus: Release 9.2.0.6.0 - Production on Mon Jan 17 11:58:04 2005 Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved. Connected to an idle instance. 11:58:04 SQL> startup mount; Total System Global Area 101785428 bytes SQL> select to_char(sysdate,'yyyy-mm-dd hh24:mi:ss') from dual; 11:58:15 SQL> alter session set nls_date_format='yyyy-mm-dd hh24:mi:ss'; Session altered. Elapsed: 00:00:00.00 recover database until time '2010-10-19 18:25:03'; --恢复到提交完成时刻 11:58:33 SQL> alter database open resetlogs; Database altered. Elapsed: 00:00:05.08 no rows selected Elapsed: 00:00:00.00 --注意此时数据没有被恢复。 4.第二个测试 D:\>sqlplus "/ as sysdba" SQL*Plus: Release 9.2.0.6.0 - Production on Mon Jan 17 11:48:50 2005 Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved. Connected to an idle instance. 11:48:50 SQL> startup Total System Global Area 101785428 bytes Table created. Elapsed: 00:00:00.04 1 row created. Elapsed: 00:00:00.00 1 row created. Elapsed: 00:00:00.00 1 row created. Elapsed: 00:00:00.00 Commit complete. Elapsed: 00:00:00.00 Table dropped. Elapsed: 00:00:00.06 D:\>sqlplus "/ as sysdba" SQL*Plus: Release 9.2.0.6.0 - Production on Mon Jan 17 11:50:42 2005 Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved. Connected to an idle instance. 11:50:42 SQL> startup mount; Total System Global Area 101785428 bytes Session altered. Elapsed: 00:00:00.00 --此时恢复到提交一秒之后 11:51:22 SQL> alter database open resetlogs; Database altered. Elapsed: 00:00:03.09 NAME Elapsed: 00:00:00.00 --数据得以恢复 结论: |
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