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DG_Check检测

1） all 查询备库角色（确认主备关系)

set linesize 140 col dbid for 9999999999 col name for a10 col database_role for a22 col open_mode for a10 col flashback_on for a5 select dbid,name, database_role,open_mode,FLASHBACK_ON,PROTECTION_MODE,FORCE_LOGGING from v$database;

2）备库查询DG延迟（如果备库开启实施应用应该为1分钟内，正常。如果差距10多个小时，可能存在情况需要排查）set linesize 300 col name for a20 col value for a20 col time_computed for a30 select name,value,unit,time_computed from v$dataguard_stats where name in ('transport lag','apply lag');

3)备库 查询MRP进程应用情况select process,client_process,sequence#,status,BLOCK#,BLOCKS from v$managed_standby;

以上信息确认DG基本正常之后，对主库切换日志进行确认4)主库切换归档，查询备库是否接受且应用primarySQL> select thread#,sequence# from v$log where status='CURRENT';standby SQL> select DEST_ID,THREAD#,max(SEQUENCE#) from v$archived_log where APPLIED='YES' group by DEST_ID,THREAD#;primarySQL> alter system archive log current;standby SQL> select DEST_ID,THREAD#,max(SEQUENCE#) from v$archived_log where APPLIED='YES' group by DEST_ID,THREAD#;SQL> select process,client_process,sequence#,status,BLOCK#,BLOCKS from v$managed_standby; SQL> select name from v$archived_log where (thread#,sequence#) in (select THREAD#,max(SEQUENCE#) from v$archived_log where dest_id=1 group by thread#);

如果上述主库切换归档，备库未接收到日志，如下进入，DG问题排查5）主库查询归档线程状态（查询no error说明正常现象）set linesize 200 col dest_name for a40 select DEST_NAME , STATUS , RECOVERY_MODE from v$archive_dest_status;

查询归档线程是否异常

select dest_id,error from v$archive_dest;

查询DG报错信息情况

col severity for a15 col message for a70 col timestamp for a20 select severity,error_code,to_char(timestamp,'DD-MON-YYYY HH24:MI:SS') "timestamp" , message from v$dataguard_status where dest_id=4;

查询已经应用的日志列表

select name,applied from v$archived_log where name is not null and applied!='YES';

是否存在GAP异常

select * from v$archive_gap;