oracle database recover database （下篇）
1. recover database
恢复级别一共三个：recover database > recover tablespace > recover datafile ，最高级别 database 已经包含了 tablespace 和 datafile 两个级别。
目录
1. 概念解释
2. 情况说明
3. 实验过程
3.1 备份 CDB
3.2 PDBPROD1 创建测试数据
3.3 删除 CDB 控制文件
3.4 还原 CDB 控制文件
3.5 恢复 CDB 控制文件
3.6 开启 CDB
1. 概念解释
首先你得知道，recover database 这个命令是用作对所有数据文件进行恢复的，而且是完全恢复。
有个细节注意下，这个命令分为两种，一种用在 SQL 命令行，一种用在 RMAN：
SQL > recover database 仅对所有数据文件进行完全恢复，前提是控制文件为当前最新状态，不可以是还原过来的老版本或是手工重建，否则 SQL 命令行执行将返回错误。
RMAN > recover database 对所有数据文件和控制文件进行完全恢复
本例中演示对控制文件的恢复将（数据文件、归档日志、联机日志完好无损的情况下）
2. 情况说明
当前系统中，数据文件、归档日志、联机日志都完好无损，删除 CDB 级别所有控制文件，并采用 RMAN 对控制文件进行单独还原，使用 recover database 进行完全恢复。
3. 实验过程
3.1 备份 CDB
略，参考上篇
3.2 PDBPROD1 创建测试数据
查看 PDBPROD1 当前表空间及对应数据文件
[oracle@host01 trace]$ rman target sys/oracle@pdbprod1 Recovery Manager: Release 12.1.0.2.0 - Production on Fri Dec 1 14:37:15 2023 Copyright (c) 1982, 2014, Oracle and/or its affiliates. All rights reserved. connected to target database: PRODCDB (DBID=2891862819) RMAN> report schema; using target database control file instead of recovery catalog Report of database schema for database with db_unique_name PRODCDB List of Permanent Datafiles =========================== File Size(MB) Tablespace RB segs Datafile Name ---- -------- -------------------- ------- ------------------------ 7 280 SYSTEM NO /u01/app/oracle/oradata/PRODCDB/PDBPROD1/system01.dbf 8 615 SYSAUX NO /u01/app/oracle/oradata/PRODCDB/PDBPROD1/sysaux01.dbf 9 5 USERS NO /u01/app/oracle/oradata/PRODCDB/PDBPROD1/PDBPROD1_users01.dbf 13 321 EXAMPLE NO /u01/app/oracle/oradata/PRODCDB/PDBPROD1/example01.dbf 14 1 GAO NO /u01/app/oracle/oradata/PRODCDB/PDBPROD1/gao.dbf
List of Temporary Files ======================= File Size(MB) Tablespace Maxsize(MB) Tempfile Name ---- -------- -------------------- ----------- -------------------- 3 20 TEMP 32767 /u01/app/oracle/oradata/PRODCDB/PDBPROD1/temp01.dbf RMAN>
创建新的表空间recover_rman
SYS@pdbprod1> create tablespace recover_rman datafile '/u01/app/oracle/oradata/PRODCDB/PDBPROD1/recover_rman.dbf' size 1m; Tablespace created.
注意：新的表空间结构，没有在备份的数据文件和控制文件里面。
3.3 删除 CDB 控制文件
[oracle@host01 PRODCDB]$ cdb [oracle@host01 PRODCDB]$ sql SQL*Plus: Release 12.1.0.2.0 Production on Fri Dec 1 16:53:33 2023 Copyright (c) 1982, 2014, Oracle. All rights reserved. Connected to: Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production With the Partitioning, Oracle Label Security, OLAP, Advanced Analytics and Real Application Testing options SYS@PRODCDB> select name from v$controlfile; NAME -------------------------------------------------------------------------------- /u01/app/oracle/oradata/PRODCDB/control01.ctl /u01/app/oracle/fast_recovery_area/PRODCDB/control02.ctl SYS@PRODCDB> !rm -rf /u01/app/oracle/oradata/PRODCDB/control01.ctl SYS@PRODCDB> !rm -rf /u01/app/oracle/fast_recovery_area/PRODCDB/control02.ctl SYS@PRODCDB>
重启 CDB ，报错
SYS@PRODCDB> shut immediate; ORA-00210: cannot open the specified control file ORA-00202: control file: '/u01/app/oracle/oradata/PRODCDB/control01.ctl' ORA-27041: unable to open file Linux-x86_64 Error: 2: No such file or directory Additional information: 3 SYS@PRODCDB> shut abort; ORACLE instance shut down. SYS@PRODCDB> SYS@PRODCDB> startup force; ORACLE instance started. Total System Global Area 838860800 bytes Fixed Size 2929936 bytes Variable Size 570428144 bytes Database Buffers 260046848 bytes Redo Buffers 5455872 bytes ORA-00205: error in identifying control file, check alert log for more info
3.4 还原 CDB 控制文件
[oracle@host01 PRODCDB]$ rman target / Recovery Manager: Release 12.1.0.2.0 - Production on Fri Dec 1 16:58:36 2023 Copyright (c) 1982, 2014, Oracle and/or its affiliates. All rights reserved. connected to target database: PRODCDB (not mounted) RMAN> restore controlfile from tag='full_backup'; Starting restore at 01-DEC-23 using channel ORA_DISK_1 RMAN-00571: =========================================================== RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS =============== RMAN-00571: =========================================================== RMAN-03002: failure of restore command at 12/01/2023 17:00:55 RMAN-06563: control file or SPFILE must be restored using FROM AUTOBACKUP RMAN> restore controlfile from '/u01/app/oracle/fast_recovery_area/PRODCDB/autobackup/2023_12_01/o1_mf_s_1154433616_lplpljkm_.bkp'; Starting restore at 01-DEC-23 using channel ORA_DISK_1 channel ORA_DISK_1: restoring control file channel ORA_DISK_1: restore complete, elapsed time: 00:00:01 output file name=/u01/app/oracle/oradata/PRODCDB/control01.ctl output file name=/u01/app/oracle/fast_recovery_area/PRODCDB/control02.ctl Finished restore at 01-DEC-23 RMAN> alter database mount; Statement processed released channel: ORA_DISK_1 RMAN>
这时查控制文件中记录的数据文件（v$datafile 动态性能视图数据来自控制文件）
SYS@PRODCDB> set pagesize 50; SYS@PRODCDB> select name from v$datafile; NAME -------------------------------------------------------------------------------- /u01/app/oracle/oradata/PRODCDB/system01.dbf /u01/app/oracle/oradata/PRODCDB/pdbseed/system01.dbf /u01/app/oracle/oradata/PRODCDB/sysaux01.dbf /u01/app/oracle/oradata/PRODCDB/pdbseed/sysaux01.dbf /u01/app/oracle/oradata/PRODCDB/undotbs01.dbf /u01/app/oracle/oradata/PRODCDB/users01.dbf /u01/app/oracle/oradata/PRODCDB/PDBPROD1/system01.dbf /u01/app/oracle/oradata/PRODCDB/PDBPROD1/sysaux01.dbf /u01/app/oracle/oradata/PRODCDB/PDBPROD1/PDBPROD1_users01.dbf /u01/app/oracle/oradata/PRODCDB/PDBPROD2/system01.dbf /u01/app/oracle/oradata/PRODCDB/PDBPROD2/sysaux01.dbf /u01/app/oracle/oradata/PRODCDB/PDBPROD2/PDBPROD2_users01.dbf /u01/app/oracle/oradata/PRODCDB/PDBPROD1/example01.dbf /u01/app/oracle/oradata/PRODCDB/PDBPROD1/gao.dbf 14 rows selected.
恢复出来的控制文件中，是没有记录表空间 recover_rman
3.5 恢复 CDB 控制文件
使用 recover database 恢复数据库
RMAN> recover database; Starting recover at 01-DEC-23 Starting implicit crosscheck backup at 01-DEC-23 allocated channel: ORA_DISK_1 channel ORA_DISK_1: SID=12 device type=DISK Crosschecked 4 objects Finished implicit crosscheck backup at 01-DEC-23 Starting implicit crosscheck copy at 01-DEC-23 using channel ORA_DISK_1 Finished implicit crosscheck copy at 01-DEC-23 searching for all files in the recovery area cataloging files... cataloging done List of Cataloged Files ======================= File Name: /u01/app/oracle/fast_recovery_area/PRODCDB/archivelog/2023_12_01/o1_mf_1_162_lplt479s_.arc File Name: /u01/app/oracle/fast_recovery_area/PRODCDB/autobackup/2023_12_01/o1_mf_s_1154433616_lplpljkm_.bkp using channel ORA_DISK_1 starting media recovery archived log for thread 1 with sequence 162 is already on disk as file /u01/app/oracle/fast_recovery_area/PRODCDB/archivelog/2023_12_01/o1_mf_1_162_lplt479s_.arc archived log for thread 1 with sequence 163 is already on disk as file /u01/app/oracle/oradata/PRODCDB/redo01.log archived log file name=/u01/app/oracle/fast_recovery_area/PRODCDB/archivelog/2023_12_01/o1_mf_1_162_lplt479s_.arc thread=1 sequence=162 archived log file name=/u01/app/oracle/oradata/PRODCDB/redo01.log thread=1 sequence=163 creating datafile file number=15 name=/u01/app/oracle/oradata/PRODCDB/PDBPROD1/recover_rman.dbf archived log file name=/u01/app/oracle/oradata/PRODCDB/redo01.log thread=1 sequence=163 media recovery complete, elapsed time: 00:00:01 Finished recover at 01-DEC-23 RMAN>
请注意倒数第6 行：creating datafile file number=14 name=/u01/app/oracle/oradata/PRODCDB/PDBPROD1/recover_rman01.dbf
完全恢复命令自动在控制文件中创建添加了 recover_rman 数据文件
再次查控制文件中记录的数据文件
SYS@PRODCDB> select name from v$datafile; NAME -------------------------------------------------------------------------------- /u01/app/oracle/oradata/PRODCDB/system01.dbf /u01/app/oracle/oradata/PRODCDB/pdbseed/system01.dbf /u01/app/oracle/oradata/PRODCDB/sysaux01.dbf /u01/app/oracle/oradata/PRODCDB/pdbseed/sysaux01.dbf /u01/app/oracle/oradata/PRODCDB/undotbs01.dbf /u01/app/oracle/oradata/PRODCDB/users01.dbf /u01/app/oracle/oradata/PRODCDB/PDBPROD1/system01.dbf /u01/app/oracle/oradata/PRODCDB/PDBPROD1/sysaux01.dbf /u01/app/oracle/oradata/PRODCDB/PDBPROD1/PDBPROD1_users01.dbf /u01/app/oracle/oradata/PRODCDB/PDBPROD2/system01.dbf /u01/app/oracle/oradata/PRODCDB/PDBPROD2/sysaux01.dbf /u01/app/oracle/oradata/PRODCDB/PDBPROD2/PDBPROD2_users01.dbf /u01/app/oracle/oradata/PRODCDB/PDBPROD1/example01.dbf /u01/app/oracle/oradata/PRODCDB/PDBPROD1/gao.dbf /u01/app/oracle/oradata/PRODCDB/PDBPROD1/recover_rman.dbf 15 rows selected.
3.6 开启 CDB
因为动了“控制文件”，所以，必须得以 resetlogs 方式打开，为啥？
SYS@PRODCDB> alter database open; alter database open * ERROR at line 1: ORA-01589: must use RESETLOGS or NORESETLOGS option for database open SYS@PRODCDB> alter database open resetlogs;
Database altered.
你的疑问在于：recover database 语句明明是个完全恢复的动作，为何成功之后，依然需要 resetlogs ？因为 recover database 命令只能修复控制文件中数据文件的物理结构信息，无法修改控制文件中的日志序列号，无法像数据文件一样，应用归档和联机日志前滚，所以控制文件中的序列号依然是老旧的，因此，只能通过重置序列号来打开数据库。
以 resetlogs 打开之后，日志组序列号重置为 1，新的版本化身 incarnation 出现
RMAN> list incarnation; List of Database Incarnations DB Key Inc Key DB Name DB ID STATUS Reset SCN Reset Time ------- ------- -------- ---------------- --- ---------- ---------- 1 1 PRODCDB 2891862819 PARENT 1 22-OCT-15 2 2 PRODCDB 2891862819 CURRENT 2302159 01-DEC-23
incarnation是什么，请参考官方文档。
