检查归档同步情况
一、查看数据库的情
select database_role,flashback_on,open_mode,current_scn from v$database
DATABASE_ROLE FLASHBACK_ON OPEN_MODE CURRENT_SCN
---------------- ------------------ -------------------- ---------------
PHYSICAL STANDBY NO READ ONLY WITH APPLY 16657544972059
二、查看归档的最大线程与最大接收的归档情况
select thread#,max(sequence#) from v$archived_log group by thread#;
生产库：
SQL> select thread#,max(sequence#) from v$archived_log group by thread#;
THREAD# MAX(SEQUENCE#)
---------- --------------
1 136973
2 132693
4 149599
3 133277
--DG库
SYS@hisnewdb> select thread#,max(sequence#) from v$archived_log group by thread#;
THREAD# MAX(SEQUENCE#)
---------- --------------
1 136973
2 132693
4 149598
3 133277
可见thread#4个归档是都有会过来的，sequence都能对得上。
三、查是否存在GAP
select * from v$archived_gap;
四、日志应用情况 查看延时的应用情况
select name ,value,time_computed from v$dataguard_stats where rownum<33;
NAME VALUE TIME_COMPUTED
-------------------------------- ---------------------------------------------------------------- ------------------------------
transport lag +11 06:41:27 03/04/2021 16:41:20
apply lag +11 06:41:27 03/04/2021 16:41:20
apply finish time +00 04:23:39.868 03/04/2021 16:41:20
estimated startup time 37 03/04/2021 16:41:20
可看到apply lag的应用已经延时11天6小时了。 apply finish time应用最快的恢复时长为4小时。
恢复流程
应用日志
alter database recover managed standby databse cancel; --取消应用日志
alter database open read only; --打开只读库
alter database recover managed standby ;
alter database recover managed standby disconnect from session; -- 后台应用，建议上面命令，放前台应用。
1）归档还在主库
归档还保留或者GAP较少的情况 方法一：
1.首先通过备库sql查出相应的 node[thread#] 和归档位置 name：
select name from v$archived_log where sequence# between &1 and &2 and thread# = &3;
2.传输上面文件到备库归档位置 archive log list
#1.asmcd命令 本地环境与asm存储cp自由。
cp arch*.pdf /home/oracle/1.dbf
3. 备库上注册归档文件alter database register logfile '归档文件绝对路径' 或rman注册日志catalog start with '';
4. 应用日志，查看select * from V$ARCHIVE_GAP;,监视是否还存在其它的GAP出现。如出现，如上面步骤循环操作。
方法二：
在配置 fal_client=${备库的监听} 和 fal_server=${主库的监听} 直接应用日志，由备库寻找日志。
2）归档已在备库
方法一：
应用日志
3）归档已经被删除或GAP较多的情况
查看归档所在的位置 alert.log日志：
提供等thread 线程4的序列为148164的归档，获取的序号有148164-148165 control_keep_record_keep_time是控制文件的重用记录数据。提示在这个记录天数内没找到归档文件，建议设置更长些天数。以便GAP找到缺失的日志。 默认7天，1-365天范围。 记录的是归档日志，各种备份记录。 不记录数据文件，表空间，redo thread记录。除非被drop，否则不会重用这部分记录
1）找到当前的最小SCN
对比数据文件最后检查点的scn，数据文件头部检查点的scn，缺失归档的对应scn（下个日志文件第一个更改号），当前数据库的scn：
select thread#,low_sequence#,high_sequence# from v$archive_gap;
col datafile_scn for 999999999999999
col DATAFILE_HEADER_SCN for 999999999999999
col current_scn for 999999999999999
col next_change# for 999999999999999
select ( select min(d.checkpoint_change#) from v$datafile d ) datafile_scn ,
( select min(d.checkpoint_change#) from v$datafile_header d where rownum=1) datafile_header_scn,
(select current_scn from v$database) current_scn,
(select next_change# from v$archived_log where sequence#=148164 and resetlogs_change# = (select d.resetlogs_change# from v$database d ) and rownum=1 ) next_change#
from dual;
DATAFILE_SCN DATAFILE_HEADER_SCN CURRENT_SCN NEXT_CHANGE#
---------------- ------------------- ---------------- ----------------
16657544969028 16657544972060 16657544972059
取上面最小的scn作为增量备份的SCN
2）主库做SCN增量备份
停用备库的日志应用
alter database recover managed standby database cancel;
rman备份
切换日志 切记备份当前控制文件 增量scn备份
run {
allocate channel c1 device type disk;
allocate channel c2 device type disk;
allocate channel c3 device type disk;
allocate channel c4 device type disk;
allocate channel c5 device type disk;
allocate channel c6 device type disk;
CONFIGURE DEVICE TYPE DISK PARALLELISM 6 BACKUP TYPE TO BACKUPSET;
backup as compressed backupset current controlfile for standby format '/home/oracle/backup/backup_ctl_%U.rman';
backup as compressed backupset incremental from scn 16657544969028 database format '/home/oracle/backup/backup_%d_%s_%c_%U_%T.rman' include
current controlfile for standby filesperset 10 tag 'forsdb_16657544969028_0304';
release channel c1 ;
release channel c2 ;
release channel c3 ;
release channel c4 ;
release channel c5 ;
release channel c6 ;
传输备份文件到备库
scp -rp /home/oracle/backup/backup host2:/home/oracle
介质恢复备库
查出控制文件的绝对目录位置，后停备库 启动到nomount 恢复控制文件 启动到mount 恢复数据文件 检查rman进展
select name from v$controlfile;
shu immediate;
startup nomount;
rman target / <<eof
restore standby controlfile from '/home/oracle/backup/backup_ctl_%U.rman';
alter database mount;
eof
如果没有单独备份standby controlfile，就一个一个文件来测试恢复standby controflie
restore standby controlfile to '/oradata/hisnewdb/control01.ctl' from '/home/oracle/backup/某个文件';
如果文件太多，可以先rman注册文件后，再恢复控制文件。 要找开备库mount状态才能注册
rmant target / <<eof
startup mount;
catalog start with '/home/oracle/backup/';
list backup of controlfile;
restore standby controlfile automatic;
eof
#大概是这样。restore standby controlfile automatic;如果不通，就采用上面list的信息，找到具体含有standby controflile的备份文件，再通过restore standby controfile from '';来恢复 。
catalog start with '/home/oracle/backup/';
recover database noredo;
查看rman的恢复进展：
set line 9999
select sid,serial#,opname,round(sofar/totalwork*100) completed,trunc(elapsed_seconds/60) elapsed ,trunc(time_remaining/60) remaining,context ,target,sofar,totalwork
from v$session_longops
where opname like 'RMAN%' and opname not like '%aggregate%' and totalwork!=0 and sofar<>totalwork;
应用日志
检查standby redo files是否存在:
select * from v$standby_log;
注册standby redolog files
-- 添加单个文件：
alter database add standby logfile group {组号} 'standby redo logs files 绝对目录文件';
-- 添加多个standby redologs file
alter database add standby logfile group {组号} ('standby redo logs file 1','logfiles2');
应用日志
alter database recover managed standby database cancel ;
startup mount;
alter database open read only;
select open_mode,status,protection_level,protection_mode from v$database ;
--前台应用日志
alter database recover managed standby database ;
-- 8 parallel 后台应用日志
alter database recover managed standby database parallel 8 disconnect from session;
检查应用日志的情况
检查各个线程thread#的最大应用日志的序列，与主库进行对比。
select thread#,max(sequence#) from v$archived_log where applied='YES' group by thread#;
