Oracle Dataguard Important Command

In this blog, We will look some important oracle dataguard command.Following command will be useful for dataguard administration

Check the Dataguard database status on primary and standby

select status,instance_name,database_role,protection_mode from v$database,v$instance;

Query to apply redo log on standby. Following command useful for real time apply

ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE; 

To Start the MRP process using archive log

alter database recover managed standby database disconnect from session;

To check applied archieve logs

SELECT SEQUENCE#, APPLIED FROM V$ARCHIVED_LOG;

Cancel the MRP Process

alter database recover managed standby database cancel;

Status of MRP Process

select process,status,client_process,thread#,sequence#,block#,blocks,delay_mins from v$managed_standby;

To get the difference between Received and applied logs.

select  MAX_RECEIVED,MAX_APPLIED,(MAX_RECEIVED - MAX_APPLIED) as "Difference" from (SELECT
    ARCHIVED_THREAD#, MAX(ARCHIVED_SEQ#) as MAX_RECEIVED,
    APPLIED_THREAD#,  MAX(APPLIED_SEQ#) as  MAX_APPLIED
 FROM
   V$ARCHIVE_DEST_STATUS) ARCH ; 

To check the status of Archive log

col name for a50;
col thread# for a30;
col SEQUENCE# for a30;
select THREAD#,SEQUENCE#,name,APPLIED from v$ARCHIVED_LOG;

select THREAD#,SEQUENCE#,FIRST_TIME,NEXT_TIME,BLOCKS,BLOCK_SIZE,ARCHIVED,APPLIED,STATUS,IS_RECOVERY_DEST_FILE from v$ARCHIVED_LOG;

TO check if dataguard in synchronizing with standby.

select thread#,max(sequence#) from v$archived_log where applied='YES' group by thread#;

Dataguard Error with timestamp

select message, to_char(timestamp,'HH:MI:SS') timestamp
 from v$dataguard_status
 where severity in ('Error','Fatal')
 order by timestamp;

SELECT MESSAGE FROM V$DATAGUARD_STATUS;

select dest_name,status,error from v$archive_dest where status='ERROR';

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