Oracle ADG相关查询的实现
作者:为中华崛起而奋斗
本文主要介绍了ADG(Active Data Guard)环境下的故障排查步骤,文中通过示例代码介绍的非常详细,对大家的学习或者工作具有一定的参考学习价值,需要的朋友们下面随着小编来一起学习学习吧
1、判断有无ADG
show parameter dest show parameter log_archive_config select open_mode,protection_mode,database_role,switchover_status from v$database;
2、主库查询gap
set lines 222 pages 100 col error for a20 col gap_status for a20 col dest_name for a20 select dest_id,dest_name,status,type,error,gap_status from v$archive_dest_status where type='PHYSICAL';

3、备库查询GAP
select * from v$archive_gap; --无结果说明无gap
GAP_STATUS: NO GAP:无GAP LOG SWITCH GAP : 有GAP,日志还没有切换完成,不需要人工干预 RESOLVABLE GAP:有GAP,但是可以自动解决,不需要人工干预 UNRESOLVABLE GAP:有GAP,不能自动解决,需要人工干预(从主库SCP归档到备库并重新注册归档恢复) LOCALLY UNRESOLVABLE GAP:有GAP,不能从本机获取日志自动解决,可以存其他机器获取日志自动解决
4、查看主库多节点最大日志编号、查备库recover到的日志序号
select thread#,max(sequence#) from gv$archived_log group by thread# order by 1; tail -1000f alert.log
5、主备库查看ADG异常信息
select status,error,valid_type,valid_role,db_unique_name from v$archive_dest;
6、主库查找备库缺失的日志路径和名称:
set lines 200 pages 100 col name for a100 select name from v$archived_log where thread#=1 and dest_id=1 and sequence# between xxx and xxx;
7、判断未应用日志(备库查)
select thread#,0 not_send_count,not_apply_count
from (select s.thread#,
s.sequence# - ( select max(s.sequence#) seq
from gv$managed_standby i
where i.process='ARCH'
and i.thread# = s.thread#) not_apply_count
from gv$managed_standby s
where s.process = 'MRP0')
where not_apply_count >= 0;8、判断未传输日志(主库查)
with temp as
( select process,thread#,max(sequence#) seq
from gv$managed_standby
where process in ('ARCH','LNS')
group by process,thread#)
select aa.thread#,bb.seq - aa.seq not_send_count,0 not_apply_count
from temp aa.temp bb
where aa.process='ARCH'
and bb.process='LNS'
and aa.thread#=bb.thread#
and bb.seq - aa.seq >= 0
order by 1;9、查案备库未应用日志(在备库执行)
select dest_id,count(*) from v$archived_log where applied='NO' group by thread#,dest_id order by 1; select thread#,count(*) from v$archived_log where applied='NO' group by thread#,dest_id order by 1; select thread#,sequence#,applied from v$archived_log where applied='NO'; select thread#,dest_id,to_char(FIRST_TIME,'YYYY-MM-DD HH24:MI:SS'),name,applied,deleted,status from v$archived_log where applied='NO' order by 3;
10、查询同步信息及相关进程(在备库执行)
set lines 222 pages 100 col client_pid for a10 select inst_id,thread#,process,status,client_pid,sequence# from gv$managed_standby;

主要看MRP0进程(日志应用进程)
MRP0有多个状态:
WAIT_FOR_GAP:有GAP,看看GAP是否可以自动解决,不需要人工干预
APPLYING_LOG:正在应用日志
WAIT_FOR_LOG:正在等待日志同步
如果WAIT_FOR_GAP持续太久就需要关注了
如果WAIT_FOR_GAP持续不长,可以看看主库当天归档量的大小
11、查询一周的归档量
select logtime,count(*),round(sum(sr)/1024/1024/1024,2) size_gb
from ( select to_char(first_time,'YYYY-MM-DD') as logtime
(a.blocks * a.block_size) sz
from gv$archived_log a
where a.dest_id = 1
and a.first_time > trunc(sysdate - 8))
group by logtime
order by logtime;12、关闭日志应用
alter database recover managed standby database cancel;
13、开启日志应用
alter database recover managed standby database parallel 16 using current logfile disconnect from session; alter database recover managed standby database using current logfile disconnect from session;
14、ADG备库删除归档
1、一般备库应用完归档会自动删除已经应用的归档 2、备库归档不要使用强制删除(force),如果备库强制删除未应用的归档,此时主库相应的归档也会被策略删除,ADG主备就不可用了 select count(*) from v$archive_gap; select count(*) from v$archived_log where applied='NO';
15、停止主库向备库传输日志
在主库操作,将主库的"log_archive_dest_state_2"设置为DEFER,停止主库归档向备库传输,可缓解备库归档空间压力,等备库归档应用并自动删除足够多时,再将"log_archive_dest_state_2"设置为enable,开启主库对备库的传输 show parameter log_archive_dest_state_2 alter system set log_archive_dest_state_2=defer; alter system set log_archive_dest_state_2=enable;
16、手动应用归档日志(在备库执行)
asmcmd cd +ARCH/archivelog/2025-01-14/ cp thread_2_seq_458535 /tmp scp /tmp/thread_2_seq_458535 bakup:/tmp/ sqlplus / as sysdba alter database register logfile '/tmp/thread_2_seq_458535'; #或 rman target / catalog start with '/tmp/xxxx.dbf'
17、ADG切换
ADG切换之后,主备库不传输的情况,除了密码文件的问题,有可能是触发器的问题。(主库禁用系统触发器,等回切之后要改成true,一直是备库禁用系统触发器)
alter system set "_system_tring_enabled"=FALSE;
ADG主备切换,如果主库有多个备库,先验证每个备库是否都通,如果不能通的话需要把不通的备库的log_archive_dest_*参数置空,要不主库的归档一直发不到不通的备库,其他备库一直等待归档传输
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