oracle 12c 验证数据库恢复是否有效

郑全

数据库做了备份，一直没有机会进行恢复（其实永远没有机会恢复也好，说明系统很健壮），心里总是憋得慌，如果哪天出现问题，需要恢复时，备份不可用怎么办，有人说找一个异机恢复不就得了，关键你要有机器可用，而且要安装一堆软件，以及配套的设备，比如磁带库等，麻烦，
能否在原机器上进行恢复，但又不恢复，什么，有点绕口令哈。就是在原机上模拟恢复，只是验证一下备份到磁盘，磁带的备份的有效性，并不真正恢复。

真的吗，oracle有这种功能吗 ?

真的，oracle 12c r1开始，就有这样的功能了，不信，我们往下看：

1.先看看版本嘛
   RMAN> select * from v$version;
BANNER                                                                                                            CON_ID
---------------------------------------------------------------------------------------------            ----------
Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production            0
PL/SQL Release 12.1.0.2.0 - Production                                                                0
CORE    12.1.0.2.0      Production                                                                        0
TNS for Linux: Version 12.1.0.2.0 - Production                                                      0
NLSRTL Version 12.1.0.2.0 - Production                                                                0


2.看看控制文件能否恢复到一天前

RMAN> restore controlfile until time 'sysdate-1' validate;
Starting restore at 18-AUG-19
using channel ORA_DISK_1
channel ORA_DISK_1: starting validation of datafile backup set
channel ORA_DISK_1: reading from backup piece +FRA/ORCL/BACKUPSET/2019_08_17/ncsnf0_tag20190817t124952_0.261.1016542289
channel ORA_DISK_1: piece handle=+FRA/ORCL/BACKUPSET/2019_08_17/ncsnf0_tag20190817t124952_0.261.1016542289 tag=TAG20190817T124952
channel ORA_DISK_1: restored backup piece 1
channel ORA_DISK_1: validation complete, elapsed time: 00:00:01
Finished restore at 18-AUG-19

哇，还真的在读哈 。

3.看看参数文件可否

RMAN> restore spfile until time 'sysdate-1' validate;
Starting restore at 18-AUG-19
using channel ORA_DISK_1
channel ORA_DISK_1: starting validation of datafile backup set
channel ORA_DISK_1: reading from backup piece +FRA/ORCL/BACKUPSET/2019_08_17/ncsnf0_tag20190817t124952_0.261.1016542289
channel ORA_DISK_1: piece handle=+FRA/ORCL/BACKUPSET/2019_08_17/ncsnf0_tag20190817t124952_0.261.1016542289 tag=TAG20190817T124952
channel ORA_DISK_1: restored backup piece 1
channel ORA_DISK_1: validation complete, elapsed time: 00:00:01
Finished restore at 18-AUG-19
RMAN>
RMAN>

4.看看数据库呢

RMAN> restore database until time 'sysdate-1' validate;
Starting restore at 18-AUG-19
using channel ORA_DISK_1
channel ORA_DISK_1: starting validation of datafile backup set
channel ORA_DISK_1: reading from backup piece +FRA/ORCL/BACKUPSET/2019_08_17/nnndf0_tag20190817t124952_0.260.1016542193
channel ORA_DISK_1: piece handle=+FRA/ORCL/BACKUPSET/2019_08_17/nnndf0_tag20190817t124952_0.260.1016542193 tag=TAG20190817T124952
channel ORA_DISK_1: restored backup piece 1
channel ORA_DISK_1: validation complete, elapsed time: 00:00:03
Finished restore at 18-AUG-19

5.如果有磁带的情况，能否验证呢

RMAN> run{
2> allocate channel c1 device type sbt;
3> restore database validate;
4> }
released channel: ORA_DISK_1
allocated channel: c1
channel c1: SID=266 device type=SBT_TAPE
channel c1: Oracle Secure Backup
Starting restore at 18-AUG-19
new media label is "rman-000005,rman-000007,rman-000008,rman-000009,rman-000010,rman-000011" for piece "07u9hdc7_1_1"
channel c1: starting validation of datafile backup set
channel c1: reading from backup piece 07u9hdc7_1_1
channel c1: piece handle=07u9hdc7_1_1 tag=TAG20190818T161503
channel c1: restored backup piece 1
channel c1: validation complete, elapsed time: 00:00:45
Finished restore at 18-AUG-19
released channel: c1


看到了吧，oracle12c 硬是可以哈。你还可以看看以下命令，具体就不演示了,有新发现，不要忘了到思庄论坛说一声哈。


restore preview;
restore validate header;