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2 Replies Latest reply: Mar 26, 2013 12:39 AM by Hemant K Chitale RSS

DG related questions

999142 Newbie
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Hi,

I am new to Data Guard. I have gone through oracle 11gR2 data Guards docs. I have few queries.

1) Standby control file inherits attributes from the Primary database. What makes the standby control file separate from the primary control file?

2) Does Standby Archival operation depends on primary database archival operation?

3) A primary DB can maintain lot of standby databases. So DB_UNIQUE_NAME init parameter seperates which standby is maintained for LOG_ARCHIVE_DEST_n. Am I correct?

Any help will be highly appreciated.

Regards
  • 1. Re: DG related questions
    Chanchal Wankhade Journeyer
    Currently Being Moderated
    >
    1) Standby control file inherits attributes from the Primary database. What makes the standby control file separate from the primary control file?
    Both are same. since standby database resides on other server so both primary and standby database cannot share same control file.
    2) Does Standby Archival operation depends on primary database archival operation?
    No. You mean if primary database is in archived mode then standby alos will be archived mode. Your standby database may or may not be in archived mode since there is one to one DR you have established. Your primary database must be in Archived log mode otherwise what is the use of creating DR.
    3) A primary DB can maintain lot of standby databases. So DB_UNIQUE_NAME init parameter seperates which standby is maintained for LOG_ARCHIVE_DEST_n. Am I correct?
    Yes. Every standby database must have different db_unique_name otherwise you someone will be in mess.
  • 2. Re: DG related questions
    Hemant K Chitale Oracle ACE
    Currently Being Moderated
    1. There is a difference. The standby controlfile has, internally, an atribute set to define it as a standby controlfile. That attribute is set when you execute an "ALTER DATABASE CREATE STANDBY CONTROLFILE AS 'location'; "
    Similarly, when you query V$DATABASE for "DATABASE_ROLE", it determines the database role based on the attribute in the controlfile.

    2. Archival at the standby site is from the standby redo logs if you are using SRLs.

    3. The Primary identifies the standbys based on LOG_ARCHIVE_DEST_n SERVICE_NAME. However, it is good practice to define a different DB_UNIQUE_NAME for each standby.


    Hemant K Chitale

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