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3 Replies Latest reply: Mar 31, 2013 10:59 PM by MahirM.Quluzade RSS

Standby Questons

999551 Newbie
Currently Being Moderated
Hello,

DB: 11.2.0.2 & OS: RHEL5

1)How can I start MRP on physical standby of automatic way after a database startup?

2) Why do I see "Media recovery Log" message in standby alert log?

3) Can we use “SELECT CURRENT_SCN FROM V$DATABASE” to find out if both primary and standby is sync or not?

Regards
  • 1. Re: Standby Questons
    Acooper Explorer
    Currently Being Moderated
    The answer to your questions are ... read the docs at http://tahiti.oracle.com
  • 2. Re: Standby Questons
    Hemant K Chitale Oracle ACE
    Currently Being Moderated
    1. RECOVER MANAGED STANDBY DATABASE DISCONNECT FROM SESSION;

    2. It is an informational message

    3. Yes


    Hemant K Chitale
  • 3. Re: Standby Questons
    MahirM.Quluzade Guru
    Currently Being Moderated
    Hi,

    DB: 11.2.0.2 & OS: RHEL5
    1)How can I start MRP on physical standby of automatic way after a database startup?
    If your data guard is managed manually, it means with SQLPlus, then
    Start MRP :
     
     ALTER DATABASE RECOVER MANAGED SATANDBY DATABASE DISCONNECT FROM SESSION; 
     ALTER DATABASE RECOVER MANAGED SATANDBY DATABASE USING CURRENT LOGFILE DISCONNECT FROM SESSION; 
    Stop MRP
     ALTER DATABASE RECOVER MANAGED SATANDBY DATABASE CANCEL; 
    If you using Broker-Managed Data Guard
     DGMGRL> edit database <standby database> set state='APPLY-ON';  -- Start
     
     DGMGRL> edit database <standby database> set state='APPLY-OFF'; -- Stop
    >
    2) Why do I see "Media recovery Log" message in standby alert log?
    As you know Alert log is writing by background processes. Media recovery in alert log is writing MRP process, with is Redo Apply service using this process.
    >
    3) Can we use “SELECT CURRENT_SCN FROM V$DATABASE” to find out if both primary and standby is sync or not?
    Yes you can. But every time, standby curerent_scn equel or less than primary cureent_scn.
    Also you can use sequences archived_log files.
    select max(sequence#) from v$archived_log; -- return on primary is latest seqence of archived redo  log.
    
    select max(sequence#) from v$archived_log; -- return on standby is latest seqence of received redo  log.
     
    select max(sequence#) from v$archived_log
      where applied='YES'; -- return on standby is latest seqence of apllied received redo log.
    Regards
    Mahir M. Quluzade
    http://mahir-quluzade.com

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