SQL> select open_mode,protection_mode,protection_level,database_role role,switchover_status from gv$database;
OPEN_MODE PROTECTION_MODE PROTECTION_LEVEL ROLE SWITCHOVER_STATUS
-------------------- -------------------- -------------------- ---------------- --------------------
READ WRITE MAXIMUM PERFORMANCE MAXIMUM PERFORMANCE PRIMARY TO STANDBY
--主库上停掉传输进程
SQL> alter system set log_archive_dest_state_2='defer';
System altered.
备库129：
SQL> select open_mode,protection_mode,protection_level,database_role role,switchover_status from gv$database;
OPEN_MODE PROTECTION_MODE PROTECTION_LEVEL ROLE SWITCHOVER_STATUS
-------------------- -------------------- -------------------- ---------------- --------------------
READ ONLY WITH APPLY MAXIMUM PERFORMANCE MAXIMUM PERFORMANCE PHYSICAL STANDBY NOT ALLOWED
--从库上停掉应用进程
alter database recover managed standby database cancel;
System altered.
SQL> alter system switch logfile;
System altered.
SQL> /
System altered.
SQL> /
System altered.
SQL> create table testg(id number);
Table created.
SQL> alter system switch logfile;
System altered.
SQL> archive log list
Database log mode Archive Mode
Automatic archival Enabled
Archive destination /u01/arch
Oldest online log sequence 120
Next log sequence to archive 122
Current log sequence 122
主库130：
--开启传输进程
SQL> alter system set log_archive_dest_state_2='enable';
System altered.
SQL> select open_mode,protection_mode,protection_level,database_role role,switchover_status from gv$database;
OPEN_MODE PROTECTION_MODE PROTECTION_LEVEL ROLE SWITCHOVER_STATUS
-------------------- -------------------- -------------------- ---------------- --------------------
READ WRITE MAXIMUM PERFORMANCE MAXIMUM PERFORMANCE PRIMARY UNRESOLVABLE GAP <----这里发生变化
备库129：
--开启应用进程
SQL> alter database recover managed standby database using current logfile disconnect from session;
Database altered.
SQL> select open_mode,protection_mode,protection_level,database_role role,switchover_status from gv$database;
OPEN_MODE PROTECTION_MODE PROTECTION_LEVEL ROLE SWITCHOVER_STATUS
-------------------- -------------------- -------------------- ---------------- --------------------
READ ONLY WITH APPLY MAXIMUM PERFORMANCE MAXIMUM PERFORMANCE PHYSICAL STANDBY NOT ALLOWED
--查看备库延迟
col value format a30
col delay_time format a30
set lines 1000
select inst_id,name,value,datum_time from gv$dataguard_stats;
INST_ID NAME VALUE DATUM_TIME
---------- -------------------------------- ------------------------------ ------------------------------
1 transport lag +00 00:09:25 05/19/2025 21:15:56
1 apply lag +00 02:44:20 05/19/2025 21:15:56
1 apply finish time +00 00:00:00.001
1 estimated startup time 6
处理过程
1、备库129检查延迟情况、gap情况：
--查看备库延迟
col value format a30
col delay_time format a30
set lines 1000
SQL> select inst_id,name,value,datum_time from gv$dataguard_stats;
INST_ID NAME VALUE DATUM_TIME
---------- -------------------------------- ------------------------------ ------------------------------
1 transport lag +00 00:41:35 05/19/2025 21:48:06
1 apply lag +00 03:16:30 05/19/2025 21:48:06
1 apply finish time +00 00:00:00.001
1 estimated startup time 6
SQL>
2、备库确认当前最小SCN号
备库129执行：
SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;
Database altered.
SQL> col current_scn for 999999999999999
SQL> SELECT CURRENT_SCN FROM V$DATABASE;
CURRENT_SCN
----------------
2585611
SQL> select min(f.checkpoint_change#) from v$datafile_header f, v$datafile d
2 where f.file# =d.file# and d.enabled != 'READ ONLY' ;
分别查出了备库的当前SCN和文件头的最小SCN，强烈建议使用文件头最小SCN在主库进行增量备份。由于这个实验中文件头最小SCN没有，因此使用当前SCN在主库进行增量备份！
SQL> ALTER SYSTEM SET standby_file_management='AUTO' SCOPE=BOTH;
主库130：
SQL> select FILE#,to_char(CREATION_TIME,'yyyy-mm-dd hh24:mi:ss') CREATION_TIME,STATUS,LAST_TIME,name from v$datafile where CREATION_CHANGE#> 2585611;(备库当前SCN号)
no rows selected
说明：在备库当前SCN号之后主库没有新增加数据文件。
SQL>
备库129
--查询备库数据文件信息：
SQL> select file#, name from v$datafile;
3、主库通过基于SCN方式RMAN备份数据库
#!/bin/bash
$ORACLE_HOME/bin/rman target / log=/u01/backup/backup_20250519.log <<EOF
run
{
allocate channel t1 type disk;
allocate channel t2 type disk;
BACKUP as compressed backupset INCREMENTAL FROM SCN 2585611（取备库最小SCN号） DATABASE FORMAT '/u01/backup/dg_%U' tag 'FORSTANDBY';
release channel t1;
release channel t2;
}
EOF
主数据库备份完毕后，备份一下主库的控制文件：
SQL> ALTER DATABASE CREATE standby controlfile AS '/u01/backup/standby_20250519.ctl';
Total System Global Area 2505338880 bytes
Fixed Size 2255832 bytes
Variable Size 620758056 bytes
Database Buffers 1879048192 bytes
Redo Buffers 3276800 bytes
Database mounted.
备份备库当前的控制文件：
rman target /
backup current controlfile format '/u01/backup/standbycurrent_20250519.ctl';
备库主机上查看文件：
[root@11rac02 ~]# ll /u01/backup/
total 20940
-rw-r--r-- 1 oracle oinstall 1814 May 19 22:15 backup_20250519.log
-rw-r----- 1 oracle oinstall 172032 May 19 22:15 dg_0d3pski3_1_1
-rw-r----- 1 oracle oinstall 81920 May 19 22:15 dg_0e3pski3_1_1
-rw-r----- 1 oracle oinstall 1114112 May 19 22:15 dg_0f3pskij_1_1
-rw-r----- 1 oracle oinstall 10092544 May 19 23:11 standbycurrent_20250519.ctl <----备库当前的控制文件备份
-rw-r----- 1 oracle oinstall 9977856 May 19 22:15 standby_20250519.ctl
在备库恢复之前，把主库的备份集信息注册到备库中：
rman target /
RMAN> CATALOG START WITH '/u01/backup';
using target database control file instead of recovery catalog
searching for all files that match the pattern /u01/backup
List of Files Unknown to the Database
=====================================
File Name: /u01/backup/dg_0f3pskij_1_1
File Name: /u01/backup/backup_20250519.log
File Name: /u01/backup/dg_0e3pski3_1_1
File Name: /u01/backup/standby_20250519.ctl
File Name: /u01/backup/dg_0d3pski3_1_1
Do you really want to catalog the above files (enter YES or NO)? yes
cataloging files...
cataloging done
List of Cataloged Files
=======================
File Name: /u01/backup/dg_0f3pskij_1_1
File Name: /u01/backup/dg_0e3pski3_1_1
File Name: /u01/backup/standby_20250519.ctl
File Name: /u01/backup/dg_0d3pski3_1_1
List of Files Which Where Not Cataloged
=======================================
File Name: /u01/backup/backup_20250519.log
RMAN-07517: Reason: The file header is corrupted
SQL> shutdown immediate;
SQL> startup nomount
$ rman target /
RMAN> restore controlfile from '/u01/backup/standby_20250519.ctl';
SQL> alter database open;
Database altered.
7、开启DG同步机制
备库开启恢复
SQL> ALTER DATABASE recover managed standby DATABASE using current logfile disconnect FROM SESSION;
Database altered.
SQL> col value format a30
SQL> col delay_time format a30
SQL> set lines 1000
SQL> select inst_id,name,value,datum_time from gv$dataguard_stats;
INST_ID NAME VALUE DATUM_TIME
---------- -------------------------------- ------------------------------ ------------------------------
1 transport lag +00 00:00:00 05/20/2025 00:10:31
1 apply lag +00 00:00:00 05/20/2025 00:10:31
1 apply finish time
1 estimated startup time 6
SQL>
至此，备库增量恢复完成，主备数据库同步正常。
碰到的问题
$ORACLE_HOME/bin/rman target / log=/u01/backup/recover_20250519.log <<EOF
run
{
allocate channel t1 type disk;
allocate channel t2 type disk;
recover database noredo; --noredo 表示恢复过程中不尝试应用任何归档日志或联机重做日志（Redo Log）
release channel t1;
release channel t2;
}
EOF
using target database control file instead of recovery catalog
allocated channel: t1
channel t1: SID=17 device type=DISK
Starting recover at 19-MAY-25
channel t1: starting incremental datafile backup set restore
channel t1: specifying datafile(s) to restore from backup set
destination for restore of datafile 00001: /u01/data/orcl/system01.dbf
destination for restore of datafile 00004: /u01/data/orcl/users01.dbf
channel t1: reading from backup piece /u01/backup/dg_0d3pski3_1_1
channel t2: starting incremental datafile backup set restore
channel t2: specifying datafile(s) to restore from backup set
destination for restore of datafile 00002: /u01/data/orcl/sysaux01.dbf
destination for restore of datafile 00003: /u01/data/orcl/undotbs01.dbf
channel t2: reading from backup piece /u01/backup/dg_0e3pski3_1_1
released channel: t1
released channel: t2
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of recover command at 05/19/2025 23:18:07
ORA-19870: error while restoring backup piece /u01/backup/dg_0d3pski3_1_1
ORA-19573: cannot obtain exclusive enqueue for datafile 1