環境(備庫只需要安裝數據庫軟件)：
主庫：192.168.1.100 OS: CentOS 7.3 X64 DB: ORACLE12.2.0.1 SID: ORA12C db_unique_name: ORA12C
備庫：192.168.1.101 OS: CentOS 7.3 X64 DB: ORACLE12.2.0.1 SID: ORA12C db_unique_name: ORA12CDG
1.設置主庫爲強制歸檔模式：
(1)SQL> alter database force logging;
Database altered.
SQL> select name,force_logging from v$database;
NAME FORCE_LOG
--------------------------- ---------
ORA12C YES
(2)如果在主庫添加或者刪除數據文件時，這些文件也需要在備份添加或刪除，需要如下設置：
SQL> alter system set STANDBY_FILE_MANAGEMENT='AUTO' scope=spfile;
默認此參數是MANUAL手工方式，此方式在添加或者刪除數據文件時會導致日誌無法應用。SQL> show parameter STANDBY_FILE;
2.創建standby log files(備用日誌文件）
從庫使用standby log files來保存從主庫接收到的重做日誌。既然主要是從庫在使用，那爲什麼需要在主庫上也建立standby log files?原因主要是主庫可能轉換爲備庫，而備庫是需要有standby log files的。建立standby如要注意以下幾點：
<1>standby log files的大小和redo log files一樣。
查詢redo log files文件大小：
SQL> select group#,thread#,archived,status, bytes/1024/1024 from v$log;
GROUP# THREAD# ARC STATUS BYTES/1024/1024
---------- ---------- --- ---------------- ---------------
1 1 YES INACTIVE 200
2 1 NO CURRENT 200
3 1 YES INACTIVE 200
<2>一般而言， standbyredo 日誌文件組數要比 primary 數據庫的 online redo 日誌文件組數至少多一個。
SQL> select member from v$logfile;
SQL> alter database add standby logfile thread 1 group 11 '/oracle/oradata/ORA12C/stdby11.log' size 200m;
SQL> alter database add standby logfile thread 1 group 12 '/oracle/oradata/ORA12C/stdby12.log' size 200m;
SQL> alter database add standby logfile thread 1 group 13 '/oracle/oradata/ORA12C/stdby13.log' size 200m;
SQL> alter database add standby logfile thread 1 group 14 '/oracle/oradata/ORA12C/stdby14.log' size 200m;
3.密碼文件創建傳輸
(1)一般數據庫默認就有密碼文件，存放爲$ORACLE_HOME/dbs/orapwSID 這裏爲orapwORA12C
如果沒有則手動創建：
[oracle@ora12c ~]$ orapwd file=$ORACLE_HOME/dbs/orapwORA12C password=ccdadmin
(2)檢查REMOTE_LOGIN_PASSWORDFILE值是否爲 EXCLUSIVE
SQL> show parameter REMOTE_LOGIN_PASSWORDFILE
如果值不是EXCLUSIVE，則：alter system set remote_login_passwordfile=exclusive scope=spfile;
(3)將密碼文件複製到備庫
[oracle@ora12c ~]$ scp $ORACLE_HOME/dbs/orapwORA12C [email protected]:/oracle/orahome/dbs/
4.db_name和db_unique_name
默認db_name和db_unique_name和實例名是一致的，這裏是ORA12C，需要注意在DG中主庫和從庫的db_unique_name是不能一致的，需要區分開。這裏我們設置主庫的db_unique_name爲ORA12C，從庫爲ORA12CDG
SQL> show parameter db_unique_name;
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_unique_name string ORA12C
設置：SQL> alter system set db_unique_name=ORA12C SCOPE=SPFILE;
--注意：雖然默認db_unique_name和db_name是一致的，但是需要顯式設置，否則在spfile中沒有此參數
5.開啓flashback
SQL> select flashback_on from v$database;
SQL> alter database flashback on;
如果碰到 ORA-01153 報錯，一定是在備庫進行此操作。需要先取消重做日誌應用，啓用閃回日誌，然後重新啓用日誌應用。
在主庫啓用flashback，不會同步備庫也啓用，必須手動在主庫和備庫上均啓用flashback。
6.配置監聽及tnsnames.ora
主庫監聽：
[oracle@ora12c ~]$ cd $ORACLE_HOME/network/admin
[oracle@ora12c admin]$ more listener.ora
SID_LIST_PRIM =
(SID_LIST =
(SID_DESC =
(GLOBAL_DBNAME = ORA12C)
(ORACLE_HOME = /oracle/orahome)
(SID_NAME = ORA12C)
)
)
PRIM =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.100)(PORT = 1521))
)
備庫監聽：
[oracle@ora12cdg admin]$ more listener.ora
SID_LIST_STDBY =
(SID_LIST =
(SID_DESC =
(GLOBAL_DBNAME = ORA12C)
(ORACLE_HOME = /oracle/orahome)
(SID_NAME = ORA12C)
)
)
STDBY =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.101)(PORT = 1521))
)
主庫tnsnames.ora（備庫和主庫一樣）：
[oracle@ora12c ~]$ cd $ORACLE_HOME/network/admin
[oracle@ora12c admin]$ more tnsnames.ora
ORA12C =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.100)(PORT = 1521))
)
(CONNECT_DATA =
(SID = ORA12C)
)
)
ORA12CDG =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.101)(PORT = 1521))
)
(CONNECT_DATA =
(SID = ORA12C)
)
)
7.重做日誌傳輸配置
(1)配置歸檔日誌路徑：
SQL> archive log list;
Database log mode Archive Mode
Automatic archival Enabled
Archive destination /oracle/archive
Oldest online log sequence 56
Next log sequence to archive 58
Current log sequence 58
SQL> alter system set log_archive_dest_1='LOCATION=/oracle/archive valid_for=(all_logfiles,all_roles) db_unique_name=ORA12C' scope=spfile;
SQL> alter system set log_archive_dest_state_1='enable' scope=spfile;
官方文檔裏說使用 valid_for=(online_logfiles, all_roles) 將導致備庫無法歸檔備用日誌文件，因爲它們不是在線日誌。使用all_logfiles選項，主備庫將都能歸檔在線以及備用日誌。如果想在備庫進行備份，並同時備份歸檔日誌的話，必須使用all_logfiles
(2)配置重做日誌到備份庫：
SQL> alter system set log_archive_dest_2='SERVICE=ORA12CDG lgwr sync affirm valid_for=(online_logfile,primary_role) db_unique_name=ORA12CDG';
SQL> alter system set log_archive_dest_state_2='enable' scope=spfile;
(3)設置db_file_name_convert和log_file_name_conver參數:
SQL> alter system set log_file_name_convert='/oracle/archive','/oracle/archive' scope=spfile;
SQL> alter system set db_file_name_convert='/oracle/oradata/ORA12C','/oracle/oradata/ORA12C' scope=spfile;
如果主備庫的目錄結構不一樣，或者主備庫在同一臺服務器上，則必須要設置db_file_name_convert和log_file_name_conver參數來進行數據文件和聯機日誌的保存路徑的轉換。
(4)STANDBY_ARCHIVE_DEST 參數不再需要，已經被官方棄用。
8.配置FAL_SERVER
這個參數指定當日誌傳輸出現問題時，備庫到哪裏去找缺少的歸檔日誌。它用在備庫接收的到的重做日誌間有缺口的時候。這種情況會發生在日誌傳輸出現中斷時，比如你需要對備庫進行維護操作。在備庫維護期間，沒有日誌傳輸過來，這時缺口就出現了。設置了這個參數，備庫就會主動去尋找那些缺少的日誌，並要求主庫進行傳輸。
在主庫:fal_server=從庫
從庫上就反過來:fal_server=主庫
SQL> alter system set FAL_SERVER='ORA12CDG';
注意:FAL_CLIENT在11g中已經廢棄，雖然可以配置但是已經不起作用了。
9.Data Guard 配置裏的另外一個庫的名字
SQL> alter system set log_archive_config = 'dg_config=(ORA12C,ORA12CDG)';
10.在備庫創建所需要的目錄以放置數據文件、控制文件和跟蹤文件等
[oracle@ora12cdg ~]$ cd /oracle/
[oracle@ora12cdg oracle]$ mkdir admin archive fast_recovery_area
[oracle@ora12cdg oracle]$ cd admin/
[oracle@ora12cdg admin]$ mkdir ORA12C
[oracle@ora12cdg admin]$ cd ORA12C/
[oracle@ora12cdg ORA12C]$ mkdir adump dpdump pfile
[oracle@ora12cdg ORA12C]$ cd /oracle/fast_recovery_area/
[oracle@ora12cdg fast_recovery_area]$ mkdir ORA12C
11.主庫生成pfile (initORA12C.ora)，並傳輸到備庫進行修改
SQL> create pfile from spfile;
[oracle@ora12c ~]$ scp /oracle/orahome/dbs/initORA12C.ora [email protected]:/oracle/orahome/dbs/
主庫pfile:
[oracle@ora12c dbs]$ more initORA12C.ora
ORA12C.__data_transfer_cache_size=0
ORA12C.__db_cache_size=2298478592
ORA12C.__inmemory_ext_roarea=0
ORA12C.__inmemory_ext_rwarea=0
ORA12C.__java_pool_size=16777216
ORA12C.__large_pool_size=83886080
ORA12C.__oracle_base='/oracle'#ORACLE_BASE set from environment
ORA12C.__pga_aggregate_target=1056964608
ORA12C.__sga_target=3154116608
ORA12C.__shared_io_pool_size=167772160
ORA12C.__shared_pool_size=570425344
ORA12C.__streams_pool_size=0
*.audit_file_dest='/oracle/admin/ORA12C/adump'
*.audit_trail='db'
*.compatible='12.2.0'
*.control_files='/oracle/oradata/ORA12C/control01.ctl','/oracle/fast_recovery_area/ORA12C/control02.ctl'
*.db_block_size=8192
*.db_file_name_convert='/oracle/oradata/ORA12C','/oracle/oradata/ORA12C'
*.db_name='ORA12C' #數據庫的名字，在整個DG的所有主、備庫都應一致
*.db_recovery_file_dest='/oracle/fast_recovery_area/ORA12C'
*.db_recovery_file_dest_size=8016m
*.db_unique_name='ORA12C'
*.diagnostic_dest='/oracle'
*.dispatchers='(PROTOCOL=TCP) (SERVICE=ORA12CXDB)'
*.fal_server='ORA12CDG'
*.log_archive_config='dg_config=(ORA12C,ORA12CDG)'
*.log_archive_dest_1='LOCATION=/oracle/archive valid_for=(all_logfiles,all_roles) db_unique_name=ORA12C'
*.log_archive_dest_2='SERVICE=ORA12CDG lgwr sync affirm valid_for=(online_logfile,primary_role) db_unique_name=ORA12CDG'
*.log_archive_dest_state_1='enable'
*.log_archive_dest_state_2='enable'
*.log_archive_format='%t_%s_%r.arc'
*.log_file_name_convert='/oracle/archive','/oracle/archive'
*.nls_language='AMERICAN'
*.nls_territory='AMERICA'
*.open_cursors=300
*.pga_aggregate_target=1000m
*.processes=500
*.remote_login_passwordfile='EXCLUSIVE'
*.sga_target=3000m
*.standby_file_management='AUTO'
*.undo_tablespace='UNDOTBS1'
備庫修改部分：
*.db_file_name_convert='/oracle/oradata/ORA12C','/oracle/oradata/ORA12C'
*.db_unique_name='ORA12CDG'
*.fal_server='ORA12C'
*.log_archive_config='dg_config=(ORA12CDG,ORA12C)'
*.log_archive_dest_1='LOCATION=/oracle/orabackup/archive valid_for=(all_logfiles,all_roles) db_unique_name=ORA12CDG'
*.log_archive_dest_2='SERVICE=ORA12C lgwr sync affirm valid_for=(online_logfile,primary_role) db_unique_name=ORA12C'
*.log_file_name_convert='/oracle/archive','/oracle/archive'
12.啓動備庫到nomount狀態：
SQL> conn /as sysdba
SQL> create spfile from pfile='/oracle/orahome/dbs/initORA12C.ora';
SQL> startup nomount
13.在主系統上執行RMAN 並連接主數據庫和輔助數據庫（即備庫）
[oracle@ora12c admin]$ rman target sys/passwd@ORA12C auxiliary sys/passwd@ORA12CDG
connected to target database: ORA12C (DBID=376201757)
connected to recovery catalog database
connected to auxiliary database: ORA12C (not mounted)
RMAN> duplicate target database for standby from active database nofilenamecheck dorecover;
14.啓用物理備用數據庫：
duplicate 完成之後，備庫是mount的。
SQL> select open_mode from v$database;
OPEN_MODE
--------------------
MOUNTED
SQL> alter database recover managed standby database disconnect from session;
15.查看主備庫同步狀態：
SQL> alter system switch logfile; //主庫
SQL> select max(sequence#) from v$archived_log;
SQL> select process, client_process, sequence#, status from v$managed_standby;
16.備庫開啓flashback：
SQL> select flashback_on from v$database;
SQL> alter database recover managed standby database cancel;
SQL> alter database flashback on;
SQL> alter database recover managed standby database disconnect from session;
17.如果要開啓Active Data Guard，按以下步驟操作即可：
(1)取消管理備用數據庫Redo Apply
SQL> alter database recover managed standby database cancel;
(2)然後以只讀方式打開數據庫
SQL> alter database open;
(3)重新開始Redo Apply
SQL> alter database recover managed standby database disconnect from session;
(4)查看備庫打開模式
SQL> select open_mode from v$database;
OPEN_MODE
--------------------
READ ONLY WITH APPLY