這里是：一看就會，一做就廢系列
數據庫演示版本為 19.3 （12.2.0.3）
該系列涉及恢復過程中使用的 5 個語句：
1. recover database
2. recover database until cancel
3. recover database using backup controlfile
4. recover database until cancel using backup controlfile
5. recover database using backup controlfile until cancel
繼續之前，你得知道什么叫還原 ？什么叫恢復 ？以及備份與恢復的基礎 點我查看己亥清爽系列
恢復級別一共三個：recover database > recover tablespace > recover datafile 本系列目的是為了演示上面 5 條命令的區別與聯系，所以不探討恢復級別以及數據庫狀態對應所使用的恢復級別問題。最高級別 database 已經包含了 tablespace 和 datafile 兩個級別。
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目錄
1. 概念解釋
2. 情況說明
3. 實驗過程
3.1 備份 CDB
3.2 PDB1 創建測試數據
3.3 刪除 PDB1 所有數據文件
3.4 還原 PDB1 所有數據文件
3.5 恢復 PDB1 所有數據文件
3.6 開啟 PDB1 進行數據驗證
1. 概念解釋
首先你得知道，recover database 這個命令是用作對所有數據文件進行恢復的，而且是完全恢復。
有個細節注意下，這個命令分為兩種，一種用在 SQL 命令行，一種用在 RMAN：
SQL > recover database 僅對所有數據文件進行完全恢復，前提是控制文件為當前最新狀態，不可以是還原過來的老版本或是手工重建，否則 SQL 命令行執行將返回錯誤。
RMAN > recover database 對所有數據文件和控制文件進行完全恢復
本例中僅演示對數據文件的完全恢復，此命令對控制文件的恢復將在下篇討論。
一句話：recover database 就是對所有數據進行完全恢復操作（控制文件、歸檔日志、聯機日志完好無損的情況下）
2. 情況說明
當前系統中，控制文件、歸檔日志、聯機日志都完好無損，刪除數據文件，進行還原，使用 recover database 進行完全恢復。
3. 實驗過程
3.1 備份 CDB
備份整個 CDB（CDB$ROOT / PDB1 / PDB$SEED）
RMAN> backup database format '/u02/backup/%s_%d_%U.full' tag 'full_backup';
RMAN> backup database format '/u02/backup/%s_%d_%U.full' tag 'full_backup'; Starting backup at 08-JUN-19 using channel ORA_DISK_1 channel ORA_DISK_1: starting full datafile backup set channel ORA_DISK_1: specifying datafile(s) in backup set input datafile file number=00001 name=/u01/app/oracle/oradata/CDB1/system01.dbf input datafile file number=00003 name=/u01/app/oracle/oradata/CDB1/sysaux01.dbf input datafile file number=00004 name=/u01/app/oracle/oradata/CDB1/undotbs01.dbf input datafile file number=00007 name=/u01/app/oracle/oradata/CDB1/users01.dbf channel ORA_DISK_1: starting piece 1 at 08-JUN-19 channel ORA_DISK_1: finished piece 1 at 08-JUN-19 piece handle=/u02/backup/8_CDB1_08u3ji4n_1_1.full tag=FULL_BACKUP comment=NONE channel ORA_DISK_1: backup set complete, elapsed time: 00:00:55 channel ORA_DISK_1: starting full datafile backup set channel ORA_DISK_1: specifying datafile(s) in backup set input datafile file number=00010 name=/u01/app/oracle/oradata/CDB1/pdb1/sysaux01.dbf input datafile file number=00009 name=/u01/app/oracle/oradata/CDB1/pdb1/system01.dbf input datafile file number=00011 name=/u01/app/oracle/oradata/CDB1/pdb1/undotbs01.dbf input datafile file number=00012 name=/u01/app/oracle/oradata/CDB1/pdb1/users01.dbf input datafile file number=00013 name=/u01/app/oracle/oradata/CDB1/pdb1/henry01.dbf channel ORA_DISK_1: starting piece 1 at 08-JUN-19 channel ORA_DISK_1: finished piece 1 at 08-JUN-19 piece handle=/u02/backup/9_CDB1_09u3ji6f_1_1.full tag=FULL_BACKUP comment=NONE channel ORA_DISK_1: backup set complete, elapsed time: 00:00:25 channel ORA_DISK_1: starting full datafile backup set channel ORA_DISK_1: specifying datafile(s) in backup set input datafile file number=00006 name=/u01/app/oracle/oradata/CDB1/pdbseed/sysaux01.dbf input datafile file number=00005 name=/u01/app/oracle/oradata/CDB1/pdbseed/system01.dbf input datafile file number=00008 name=/u01/app/oracle/oradata/CDB1/pdbseed/undotbs01.dbf channel ORA_DISK_1: starting piece 1 at 08-JUN-19 channel ORA_DISK_1: finished piece 1 at 08-JUN-19 piece handle=/u02/backup/10_CDB1_0au3ji78_1_1.full tag=FULL_BACKUP comment=NONE channel ORA_DISK_1: backup set complete, elapsed time: 00:00:25 Finished backup at 08-JUN-19 Starting Control File and SPFILE Autobackup at 08-JUN-19 piece handle=/u02/backup/c-983951798-20190608-02.CTL comment=NONE Finished Control File and SPFILE Autobackup at 08-JUN-19
3.2 PDB1 創建測試數據
連接 PDB1 查看當前數據文件
[oracle@henry ~]$ sqlplus sys/oracle@pdb1 as sysdba SQL> select name from v$datafile;
[oracle@henry ~]$ sqlplus sys/oracle@pdb1 as sysdba SQL*Plus: Release 19.0.0.0.0 - Production on Sat Jun 8 16:48:51 2019 Version 19.3.0.0.0 Copyright (c) 1982, 2019, Oracle. All rights reserved. Connected to: Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production Version 19.3.0.0.0 SQL> select name from v$datafile; NAME ------------------------------------------------ /u01/app/oracle/oradata/CDB1/pdb1/system01.dbf /u01/app/oracle/oradata/CDB1/pdb1/sysaux01.dbf /u01/app/oracle/oradata/CDB1/pdb1/undotbs01.dbf /u01/app/oracle/oradata/CDB1/pdb1/users01.dbf /u01/app/oracle/oradata/CDB1/pdb1/henry01.dbf
創建測試表 recover_db，插入數據 1，2，3 並 commit 提交
SQL> create table recover_db(id number) tablespace henry; Table created. SQL> insert into recover_db values(1); 1 row created. SQL> insert into recover_db values(2); 1 row created. SQL> insert into recover_db values(3); 1 row created. SQL> commit; Commit complete.
3.3 刪除 PDB1 所有數據文件
SQL> !rm -rf /u01/app/oracle/oradata/CDB1/pdb1/*
繼續插入數據 4，5，6 不提交，執行觸發完全檢查點，刷緩存數據，報錯（請思考：物理文件刪除，是否還可以繼續插入數據？為什么）
SQL> insert into recover_db values(4); 1 row created. SQL> insert into recover_db values(5); 1 row created. SQL> insert into recover_db values(6); 1 row created. SQL> alter system checkpoint; System altered. SQL> / alter system checkpoint * ERROR at line 1: ORA-03135: connection lost contact Process ID: 30992 Session ID: 273 Serial number: 51273
因為對表的所有操作都是在內存里面，此時和物理數據文件無關，所以可以繼續。
觸發檢查點的目的是為了將緩存數據刷入磁盤，而這時就和數據文件有關系了，第一次觸發完全檢查點刷數據，沒反應過來，第二次刷報錯，因為緩存數據要寫入磁盤，可是對應的磁盤文件被刪除，因此報錯。
請留意：插入 4，5，6 三條數據后的操作，是否有提交？完全恢復是否可以恢復出 4，5，6 ？
切換 CDB 查看 PDB1 狀態，並嘗試啟動（這里為什么 PDB1 是 MOUNT ？）
SQL> conn / as sysdba Connected. SQL> show pdbs CON_ID CON_NAME OPEN MODE RESTRICTED ---------- ------------- ---------- ---------- 2 PDB$SEED READ ONLY NO 3 PDB1 MOUNTED
SQL> alter pluggable database pdb1 open; alter pluggable database pdb1 open * ERROR at line 1: ORA-01157: cannot identify/lock data file 13 - see DBWR trace file ORA-01110: data file 13: '/u01/app/oracle/oradata/CDB1/pdb1/henry01.dbf'
因為多租戶體系中，參數文件和控制文件都處於 CDB 級別，因此，只要 CDB 是開啟的，下面所有 PDB 最低級別都是 MOUNT（哪怕這個庫已經出了問題，停止了，依然顯示MOUNT）
3.4 還原 PDB1 所有數據文件
還原數據文件
你可以連接 PDB1 還原自己
[oracle@henry ~]$ rman target sys/oracle@pdb1 Recovery Manager: Release 19.0.0.0.0 - Production on Sat Jun 8 17:13:26 2019 Version 19.3.0.0.0 Copyright (c) 1982, 2019, Oracle and/or its affiliates. All rights reserved. connected to target database: CDB1:PDB1 (DBID=2947650716, not open) RMAN> restore database from tag='FULL_BACKUP'; Starting restore at 08-JUN-19 using target database control file instead of recovery catalog allocated channel: ORA_DISK_1 channel ORA_DISK_1: SID=11 device type=DISK channel ORA_DISK_1: starting datafile backup set restore channel ORA_DISK_1: specifying datafile(s) to restore from backup set channel ORA_DISK_1: restoring datafile 00009 to /u01/app/oracle/oradata/CDB1/pdb1/system01.dbf channel ORA_DISK_1: restoring datafile 00010 to /u01/app/oracle/oradata/CDB1/pdb1/sysaux01.dbf channel ORA_DISK_1: restoring datafile 00011 to /u01/app/oracle/oradata/CDB1/pdb1/undotbs01.dbf channel ORA_DISK_1: restoring datafile 00012 to /u01/app/oracle/oradata/CDB1/pdb1/users01.dbf channel ORA_DISK_1: restoring datafile 00013 to /u01/app/oracle/oradata/CDB1/pdb1/henry01.dbf channel ORA_DISK_1: reading from backup piece /u02/backup/9_CDB1_09u3ji6f_1_1.full channel ORA_DISK_1: piece handle=/u02/backup/9_CDB1_09u3ji6f_1_1.full tag=FULL_BACKUP channel ORA_DISK_1: restored backup piece 1 channel ORA_DISK_1: restore complete, elapsed time: 00:00:36 Finished restore at 08-JUN-19
還可以連接 CDB ，還原 PDB1
RMAN> restore pluggable database pdb1 from tag='FULL_BACKUP'; Starting restore at 08-JUN-19 using channel ORA_DISK_1 channel ORA_DISK_1: starting datafile backup set restore channel ORA_DISK_1: specifying datafile(s) to restore from backup set channel ORA_DISK_1: restoring datafile 00009 to /u01/app/oracle/oradata/CDB1/pdb1/system01.dbf channel ORA_DISK_1: restoring datafile 00010 to /u01/app/oracle/oradata/CDB1/pdb1/sysaux01.dbf channel ORA_DISK_1: restoring datafile 00011 to /u01/app/oracle/oradata/CDB1/pdb1/undotbs01.dbf channel ORA_DISK_1: restoring datafile 00012 to /u01/app/oracle/oradata/CDB1/pdb1/users01.dbf channel ORA_DISK_1: restoring datafile 00013 to /u01/app/oracle/oradata/CDB1/pdb1/henry01.dbf channel ORA_DISK_1: reading from backup piece /u02/backup/9_CDB1_09u3ji6f_1_1.full channel ORA_DISK_1: piece handle=/u02/backup/9_CDB1_09u3ji6f_1_1.full tag=FULL_BACKUP channel ORA_DISK_1: restored backup piece 1 channel ORA_DISK_1: restore complete, elapsed time: 00:00:35 Finished restore at 08-JUN-19
3.5 恢復 PDB1 所有數據文件
恢復數據文件
你可以連接 PDB1 恢復自己
RMAN> recover database; Starting recover at 08-JUN-19 using channel ORA_DISK_1 starting media recovery media recovery complete, elapsed time: 00:00:00 Finished recover at 08-JUN-1
還可以連接 CDB ，恢復 PDB1
RMAN> recover pluggable database pdb1; Starting recover at 08-JUN-19 using channel ORA_DISK_1 starting media recovery media recovery complete, elapsed time: 00:00:00 Finished recover at 08-JUN-19
3.6 開啟 PDB1 進行數據驗證
打開數據庫
你可以連接 PDB1 打開自己
RMAN> alter database open; Statement processed
還可以連接 CDB ，打開 PDB1
RMAN> alter pluggable database pdb1 open; Statement processed
驗證數據
請問，完全恢復之后，recover_db 表中有幾條數據？為什么？
SQL> select * from recover_db; ID ---------- 1 2 3
因為插入 4，5，6 沒有提交，事務沒有結束，因此不具有持久性。完全恢復是恢復到宕機前最后一次 commit 的狀態。