1z0-066 Oracle Database 12c: Data Guard Administrator Questions and Answers

C, F: All backup operations can be offloaded to a single standby database, except backups of the SPFILE. Backups of the SPFILE can only be restored to the database from which they were backed up.

E: RMAN restores database files, over the network, from a physical standby database.

As of Oracle Database 12c, RMAN lets you restore or recover files by connecting, over the network, to a physical standby database that contains the required files. You can restore an entire database, data files, control files, spfile, or tablespaces.

Note: An Oracle database consists of one or more logical storage units called tablespaces, which collectively store all of the database's data. Each tablespace in an Oracle database consists of one or more files called datafiles, which are physical structures that conform to the operating system in which Oracle is running.

References: https://docs.oracle.com/database/121/SBYDB/rman.htm#SBYDB00755

A: On the Data Guard Performance page, you can monitor the Redo Generation Rate in the Primary database, and the Apply Rate and Lag Times in the Standby Database.

E: Look at the Standby Database Progress Summary Section. This displays the Transport lag and the Apply lag in a bar chart format. The Transport lag is the time difference between the last update on the primary database, and the last received redo on the standby. Whereas, the Apply lag is the same difference but pertaining to the last applied redo on the standby.

References: https://www.oracle.com/technetwork/articles/oem/havewala-odg-oem12c-1999410.html

The route between fs1 and physical standbase in the remote region, like physt2, should be SYNC or SYNC NOAFFIRM.

Note:

Fast Sync is a new Data Guard capability available with Oracle Database 12c. Fast Sync enables use of the destination parameter NOAFFIRM which specifies that the standby acknowledge receipt of redo without waiting for the write to the standby redo log file to complete. Fast Sync can improve application response time in a SYNC configuration by removing remote I/O from the total round trip time.

Active Data Guard Far Sync Architecture

The Maximum Availability protection mode provides the highest level of data protection that is possible without compromising the availability of a primary database.

When a transport is performed using SYNC/AFFIRM, the primary performs write operations and waits for acknowledgment that the redo has been transmitted synchronously to the physical standby and written to disk. A SYNC/AFFIRM transport provides an additional protection benefit at the expense of a performance impact caused by the time required to complete the I/O to the standby redo log.

References:

A: Stuck Archiver: YES

Archiver is unable to archive a redo log because the device is full or unavailable.

C: Observer : 017.example.com

E: The FastStartFailoverLagLimit configuration property is only used by the broker when enabling fast-start failover for configurations operating in maximum performance mode.

References: https://docs.oracle.com/cd/E11882_01/server.112/e40771/sofo.htm#DGBKR330

References:

https://dbaclass.com/article/flashback-primary-database-in-dataguard-environment/

https://books.google.com.pk/books?id=SNOkrDT8QLoC &pg=PA209&lpg=PA209&dq=Do+not+perform+any+nologging+operations+on+the+primary.&source=bl&ots=DIVtaA1jPy&sig=ACfU3U3PF3EOoTUwaeKJuC_I0kmiMNyZHQ&hl=en&sa=X&ved=2ahUKEwiDttKDufzmAhVR8uAKHY27Dg0Q6AEwAHoECAkQAQ#v=onepage&q=Do%20not%20perform%20any%20nologging%20operations%20on%20the%20primary.&f=false

References:

B: If fast-start failover is enabled, the observer will automatically reinstate the standby databases after failover has completed.

E: FastStartFailoverAutoReinstate= ‘FALSE’ means that the former primary database will not be reinstated automatically after a failover,

Note: The FastStartFailoverAutoReinstate configuration property causes the former primary database to be automatically reinstated if a fast-start failover was initiated because the primary database was either isolated or had crashed. To prevent automatic reinstatement of the former primary database in these cases, set this configuration property to FALSE.

The observer is the third party in an otherwise typical primary/standby Data Guard configuration. Only the observer can initiate FSFO failover. It's secondary job is to automatically reinstate a failed primary as a standby if that feature is enabled (the default).

A: Before you create a standby database you must first ensure the primary database is properly configured.

Place the primary database in FORCE LOGGING mode.

B: If archiving is not enabled, issue the following SQL statements to put the primary database in ARCHIVELOG mode and enable automatic archiving:

SQL> SHUTDOWN IMMEDIATE;

SQL> STARTUP MOUNT;

SQL> ALTER DATABASE ARCHIVELOG;

SQL> ALTER DATABASE OPEN;

References: https://docs.oracle.com/database/121/SBYDB/create_ps.htm#SBYDB4719

An RMAN recovery catalog is required so that backups taken on one database server can be restored to another database server. It is not sufficient to use only the control file as the RMAN repository because the primary database will have no knowledge of backups taken on the standby database.

Note: RMAN uses a recovery catalog to track filenames for all database files in a Data Guard environment. A recovery catalog is a database schema used by RMAN to store metadata about one or more Oracle databases. The catalog also records where the online redo logs, standby redo logs, tempfiles, archived redo logs, backup sets, and image copies are created.

References: https://docs.oracle.com/database/121/SBYDB/rman.htm#SBYDB4853