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Bộ đề thi quốc tế miễn phí – ORACLE OCE 1z0-066:Oracle Certified Expert, Oracle Database 12c: Data Guard Administrator

Number: 1z0-066

Passing Score: 800

Time Limit: 120 min

File Version: 1.0

ORACLE 1z0-066

Oracle Certified Expert, Oracle Database 12c: Data Guard Administrator

Version 1.0

QUESTION 1

There are currently 6 APPLIER and 6 PREPARER processes running and no idle APPLIER processes on your logical standby database. The MAX_SERVERS SQL apply parameter and number of archiver processes are both set to 12.

Identify two changes, each of which would allow you to increase the number of APPLIER processes.

  1. Increase the PROCESSES initialization parameter
  2. Increase the value for the MAX_SERVERS SQL apply parameter.
  3. Decrease the number of archiver processes on the standby database.
  4. Increase the PARALLEL_MAX_SERVER initialization parameter
  5. Decrease the number of PREPARER processes
  6. Increase the RECOVERY_PARALLELISM initialization parameter

Correct Answer: BE

Section: (none)

Explanation

Explanation/Reference:

There are three parameters that can be modified to control the number of processes allocated to SQL Apply: MAX_SERVERS, APPLY_SERVERS, and PREPARE_SERVERS. The following relationships must always hold true:

APPLY_SERVERS + PREPARE_SERVERS = MAX_SERVERS – 3

This is because SQL Apply always allocates one process for the READER, BUILDER, and ANALYZER roles. References: https://docs.oracle.com/cd/B28359_01/server.111/b28294/manage_ls.htm

QUESTION 2

Which three statements are true about snapshot standby databases?

  1. Snapshot standby databases may be used for rolling release upgrades.
  2. If datafiles grow while a database is a snapshot standby database, then they shrink when converted back to a physical standby database.
  3. Flashback logs are used to convert a snapshot standby database back into a physical standby database.
  4. A snapshot standby database can have Real-Time Query enabled.
  5. A guaranteed restore point is created automatically when a physical standby database is converted into a snapshot standby database.

Correct Answer: CE

Section: (none)

Explanation

Explanation/Reference:

C: Flashback Database is similar to conventional point-in-time recovery in its effects. It enables you to return a database to its state at a time in the recent past. Flashback Database uses its own logging mechanism, creating flashback logs and storing them in the fast recovery area. You can only use Flashback Database if flashback logs are available. Flashback Database is used to convert a snapshot standby database back into a physical standby database.

E: When we convert the physical standby database to snapshot standby database a guaranteed restore point is created. This guaranteed restore point is used to flashback a snapshot standby database to its original state.

Incorrect Answers:

A: Oracle Database supports the installation of database software upgrades, and the application of patch sets, in a rolling fashion—with near zero database downtime—by using Data Guard SQL Apply and logical standby databases.

References: https://docs.oracle.com/cd/E11882_01/server.112/e41134/manage_ps.htm#SBYDB4803 http://satya-dba.blogspot.se/2012/06/snapshot-standby-databases-oracle.html

QUESTION 3

Which three statements are true about Global Sequences when connected to a physical standby database with Real-Time Query enabled?

  1. If the CACHE option is set then the size of the cache must be at least 100.
  2. Their creation requires that a LOG_ARCHIVE_DEST_n parameter be defined in the standby that points back to their primary.
  3. Their usage will always have a performance impact on the primary database.
  4. Their usage may have a performance impact on the physical standby database if the CACHE size is too small
  5. They must have the NOORDER and CACHE options set.

Correct Answer: BDE

Section: (none)

Explanation

Explanation/Reference:

B: the terminal standby should have a LOG_ARCHIVE_DEST_n parameter defined that points back to the primary.

D: Because the standby’s requests for a range of sequences involve a round-trip to the primary, be sure to specify a large enough value for the CACHE keyword when you create a sequence that will be used on an Oracle Active Data Guard standby. Otherwise, performance could suffer.

E: In an Oracle Active Data Guard environment, sequences created by the primary database with the default CACHE and NOORDER options can be accessed from standby databases as well.

References: https://docs.oracle.com/database/121/SBYDB/manage_ps.htm#SBYDB5164

QUESTION 4

Examine this query and its output:

SQL> select fs_failover_status, fs_failover_current_target,

2 fs_failover_observer_present, fs_failover_oserver_host

3 from v$database:

FS_FAILOVER_STATUS FS_FAILOVER_CURRENT_TARGET FS_FAILOVER_OBSERVER_PRESENT FS_FAILOVER_OBSERVER_HOST

BYSTANDER cats NO

O17.example.com

Which are true?

  1. The observer is not connected to the database on which the query was executed.
  2. Cats is a bystander database.
  3. The observer is connected to the database on which the query was executed.
  4. The observer is currently running on o17.example.com.
  5. The observer is not running, but should run on o17.example.com.

Correct Answer: A

Section: (none)

Explanation

Explanation/Reference:

Viewing Information About the Observer

You can find information about the observer by querying the following columns in the V$DATABASE view:

  • FS_FAILOVER_OBSERVER_HOST shows the name of the computer on which the observer is running. Here it is cats.
  • FS_FAILOVER_OBSERVER_PRESENT shows whether or not the observer is connected to the local database. Here the value is NO. References: https://docs.oracle.com/cd/B19306_01/server.102/b14230/sofo.htm

QUESTION 5

Which three are true about using RMAN in a Data Guard environment?

  1. A recovery catalog is required when RMAN is used to take backups from a logical standby database in a Data Guard configuration if you plan to recover the primary using those backups.
  2. Backups of archived redo logs taken on a physical standby are interchangeable with a primary.
  3. A recovery catalog is required when RMAN is used to take backups from a physical standby database if you plan to recover the primary using those backups.
  4. Backups of control files taken on a physical standby are not interchangeable with a primary.
  5. Backups of data files taken on a physical standby are interchangeable with a primary.

Correct Answer: BCE

Section: (none)

Explanation

Explanation/Reference:

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.

RMAN commands use the recovery catalog metadata to behave transparently across different physical databases in the Data Guard environment. For example, you can back up a tablespace on a physical standby database and restore and recover it on the primary database. Similarly, you can back up a tablespace on a primary database and restore and recover it on a physical standby database.

Incorrect Answers:

A: Because a logical standby database is not a block-for-block copy of the primary database, you cannot use a logical standby database to back up the primary database

D: Backups of standby control files and nonstandby control files are interchangeable. For example, you can restore a standby control file on a primary database and a primary control file on a physical standby database. This interchangeability means that you can offload control file backups to one database in a Data Guard environment. RMAN automatically updates the filenames for database files during restore and recovery at the databases.

References: https://docs.oracle.com/cd/E11882_01/server.112/e41134/rman.htm#SBYDB4853

QUESTION 6

A customer has these requirements for their potential Data Guard implementation:

  1. Zero data loss must still be guaranteed through the loss of any one configuration component.
  2. The primary database must be protected against a regional disaster.
  3. Performance overheads on the primary should be minimized as much as possible given these requirements.
  4. Downtime on the primary database for any reason must be kept to a minimum.

Components referred to in the broker commands are:

Which Data Guard broker commands are needed to implement these requirements?

  1. EDIT DATABASE prima SET PROPERY REDOROUTES=’ (LOCAL: physt1, FASTSYNC)’; EDIT DATABASE prima SET PROPERY REDOROUTES=’ (LOCAL: fs1 SYNC)’;

EDIT FAR_SYNC fs1 SET PROPERTY REDORUOTES=’ (prima: physt2 SYNC)’; EDIT CONFIGURATION SET PROTECTION MODE AS MAXAVAILABILITY;

  1. EDIT DATABASE prima SET PROPERY REDOROUTES=’ (LOCAL: fs1 ASYNC)’; EDIT FAR_SYNC fs1 SET PROPERTY REDORUOTES=’ (prima: physt FASTSYNC)’; EDIT CONFIGURATION SET PROTECTION MODE AS MAXPROTECTION
  2. EDIT DATABASE prima SET PROPERY REDOROUTES=’ (LOCAL: fs1 SYNC)’; EDIT FAR_SYNC fs1 SET PROPERTY REDORUOTES=’ (prima: physt ASYNC)’; EDIT CONFIGURATION SET PROTECTION MODE AS MAXAVAILABILITY;
  3. EDIT DATABASE prima SET PROPERY REDOROUTES=’ (LOCAL: physt1, FASTSYNC)’; EDIT DATABASE prima SET PROPERY REDOROUTES=’ (LOCAL: fs1, FASTSYNC)’; EDIT FAR_SYNC fs1 SET PROPERTY REDORUOTES=’ (prima: physt2 ASYNC)’;

EDIT CONFIGURATION SET PROTECTION MODE AS MAXAVAILABILITY;

Correct Answer: A

Section: (none)

Explanation

Explanation/Reference:

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

Incorrect Answers:

B: There is no keyword FASTSYNC. To configure fast sync you use SYNC NOAFFIRM.

C: The route between fs1 and physical standbase in the remote region, like physt, should be SYNC, not ASYNC. D: The route between fs1 and physical standbase in the remote region, like physt2, should be SYNC, not ASYNC.

References: http://www.oracle.com/technetwork/database/availability/farsync-2267608.pdf

QUESTION 7

Examine the Data Guard configuration:

DGMGRL> show configuration:

Configuration-Animals

Protection Mode: MaxAvailability Databases:

Sheep- Primary database

Warning: ORA-16817: unsynchronized fast-start failover configuration Dogs – (*) Physical standby database (disabled)

ORA- 16661: the standby database needs to be reinstated

Fast-Start Failover: ENABLED Configuration Status: WARNING

And the fast-start failover configuration:

DGMGRL> show fast_start failover; Fast-Start Failover: ENABLED

Threshold : 30 seconds Target: dogs

Observer : 017.example.com

Lag Limit: 30 seconds (not in use) Shutdown Primary: TRUE

Auto-reinstate: TRUE

Observer Reconnect: 10 seconds Observer Override: FALSE

Configurable Failover Conditions Health Conditions:

Corrupted Controlfile YES Corrupted Dictionary YES Inaccessible Logfile NO Stuck Archiver NO Datafile Offline YES Oracle error Conditions:

ORA-01578: ORACLE data block corrupted (file # %s, block # %s) And finally the reason for the fail over:

SQL> select last_failover_reason from v$fs_failover_stats;

LAST_FAILOVER_REASON

ORA-01578: ORACLE data block corrupted (file # %s, block # %s)

Identify the task, or sequence of tasks, to bring the configuration into the SUCCESS state.

  1. Bring Dogs to the NOMOUNT state and let the broker reinstate Dogs automatically.
  2. MOUNT DOGS and issue “reinstate database dogs:” at the DGMGRL prompt while connected to Dogs.
  3. MOUNT DOGS and issue “reinstate database dogs:” at the DGMGRL prompt while connected to Sheep.
  4. Open Dogs and let the broker reinstate Dogs automatically.

Correct Answer: C

Section: (none)

Explanation

Explanation/Reference:

The command REINSTATE DATABASE reinstates a database as a new standby database in the broker configuration for the current primary database. References: https://docs.oracle.com/cd/B28359_01/server.111/b28295/dgmgrl.htm#BABDACIF

QUESTION 8

You are monitoring your Data Guard broker configuration and issue this set of DGMGRL commands:

DGMGRL> SHOW CONFIGURATION

Configuration – DRSolution

Protection Mode: MaxPerformance Databases:

Close_by-Primary database FS_inst- Far Sync

Far_away –Physical standby database Fast-Start Failover: DISABLED

Configuration Status:

SUCCESS

What is true concerning this configuration?

  1. The Close_by primary database instance forwards redo to the FS_inst Far Sync instance, which forwards the redo in turn to the Far_away physical standby database instance.
  2. The far sync instance will not forward redo to the Far_away physical standby because the Protection mode is not MaxProtection.
  3. The close_by primary database forwards redo to the Far_away physical standby directly and also sends redo to the FS_inst Far Sync instance.
  4. The far sync instance will not forward redo to the Far_away physical standby because Fast-Start Failover is disabled.
  5. The FS_inst Far Sync instance forwards redo to the Far_away physical standby only if the close_by primary database is not able to do so.

Correct Answer: A

Section: (none)

Explanation

Explanation/Reference:

An Oracle Data Guard far sync instance is a remote Oracle Data Guard destination that accepts redo from the primary database and then ships that redo to other members of the Oracle Data Guard configuration. A far sync instance manages a control file, receives redo into standby redo logs (SRLs), and archives those SRLs to local archived redo logs, but that is where the similarity with standbys ends. A far sync instance does not have user data files, cannot be opened for

access, cannot run redo apply, and can never function in the primary role or be converted to any type of standby database. References: https://docs.oracle.com/database/121/SBYDB/create_fs.htm

QUESTION 9

After converting your physical standby database to a logical database, you get an error:

DGMGRL> show configuration Configuration- proddg

Protection Mode: MaxPerformance Databases:

prod-Primary datatabse

prodsby-Physical standby database

Error: ORA-16810 multiple errors or warnings detected for database Fast-Start Failover: DISABLED

Configuration Status:

ERROR

How can you rectify the error?

  1. Add a logical standby database PRODSBY and enable it, thereby replacing the physical standby database metadata in the broker configuration.
  2. Remove the physical standby database PRODSBY from the broker configuration, add a logical standby database PRODSBY to the broker configuration and enable it.
  3. Reinstate the physical standby database PRODSBY as a logical standby, thereby replacing the physical standby database metadata in the broker configuration.
  4. Reinstate both the primary and physical standby databases. The broker will automatically detect that PRODSBY is a logical standby update to the metadata.

Correct Answer: D

Section: (none)

Explanation

Explanation/Reference:

You can reenable the standby database or reset the primary database state to ONLINE to fix the inconsistencies. References: https://docs.oracle.com/cd/B19306_01/server.102/b14230/cli.htm

QUESTION 10

Which four requirements can be met by deploying a logical standby database?

  1. Support for workloads requiring additional indexes.
  2. It can be used to create additional schemas.
  3. It can be used to create additional tables.
  4. It must have the same physical structure as the primary database.
  5. it must provide a disaster-recovery solution that protects all data with capability of performing switchovers and failovers.
  6. Support for workloads requiring additional materialized views.
  7. It can be used for Real Application Testing without affecting the disaster recovery capabilities.

Correct Answer: ACEG

Section: (none)
Explanation

Explanation/Reference:

A: DDL Statements supported by a Logical Standby Database include:

ALTER INDEX CREATE INDEX DROP INDEX

C: DDL Statements supported by a Logical Standby Database include:

CREATE TABLE DROP TABLE

Incorrect Answers:

D: The physical organization in a logical standby database is different from that of the primary database, even though the logical standby database is created from a backup copy of the primary database.

F: DDL Statements not supported by a Logical Standby Database include: CREATE MATERIALIZED VIEW

References: https://docs.oracle.com/cd/E11882_01/server.112/e41134/create_ls.htm#SBYDB4731 https://docs.oracle.com/cd/B28359_01/server.111/b28294/data_support.htm

QUESTION 11

A query on the view DBA_LOGSTDBY_UNSUPPORTED on your primary database returns several rows. As a result of this, you decide that an upgrade may not use logical standby databases.

Which three are true about upgrading Data Guard environments consisting of one physical standby database running on a separate host from the primary?

  1. The upgrade requires downtime until the upgrade of the standby is completed.
  2. The broker must be disabled during the upgrade.
  3. With manual upgrade, catupgrd.sq1 can be executed on the primary and standby databases simultaneously.
  4. The upgrade requires downtime until the upgrade of the primary is completed.
  5. The new release of the Oracle Software must be installed on both the primary and standby database hosts.
  6. Redo Apply on the standby database must be stopped while the primary database is upgraded.
  7. Fast-Start Failover can be used to protect the primary database during the upgrade.

Correct Answer: BDE

Section: (none)

Explanation

Explanation/Reference:

B: Disable the broker’s management of the configuration and then stop the broker.

E: On the primary database install the newer release of the Oracle software, and on the logical standby database, install the newer release of the Oracle software. Incorrect Answers:

C: Oracle Database 12c introduces a new command-line upgrade utility (catctl.pl). This utility replaces the catupgrd.sql script used to upgrade to previous releases of Oracle Database. The new command-line upgrade utility enables parallel processing during the database upgrade, resulting in better upgrade performance and reduced database downtime.

G: Disable fast-start failover if it is enabled. References:

https://docs.oracle.com/database/121/SBYDB/upgrades.htm https://docs.oracle.com/database/121/DGBKR/upgrade_appx.htm#DGBKR1212

QUESTION 12

You are licensed to use Oracle Active Data Guard.

Which two statements are true after enabling block change tracking on a physical standby database?

  1. It allows fast incremental backups to be offloaded to the physical standby database.
  2. It starts the CTWR process on the physical standby database instance.
  3. It allows fast incremental backups to be taken on the primary database.
  4. It starts the RVWR process on the physical standby database instance.
  5. It allows fast incremental backups to be offloaded to a snapshot standby database, when the physical standby database in converted.
  6. It starts the CTWR process on the primary database instance.

Correct Answer: AB

Section: (none)

Explanation

Explanation/Reference:

A: Many of the customers now are opting to perform RMAN backups on standby database to offload the resources of production database.

B: To enable Active Data Guard on a standby database, set the ENABLE_OPTION_ACTIVE_DATA_GUARD initialization parameter to TRUE.

Note: Fast Incremental backups is possible with Block change tracking, which is initially introduced from version 10.2 onwards, by this tool it’s very useful to reduce the RMAN incremental backup duration but it is limited only for Primary database. From 11g Oracle with Active Data Guard feature we can use Block change tracking even on Physical standby database. T

References: http://www.morganslibrary.org/reference/block_change_tracking.html

QUESTION 13

Which three are true regarding the Enterprise Manager Cloud Control Data Guard configuration verification wizard?

  1. It checks that supplemental logging is turned on if there is a logical standby database in the configuration.
  2. It verifies that parameter settings in the SPFILE or in memory or both, are consistent with the broker configuration properties for that database.
  3. It checks that the current data protection level is consistent with the broker’s configured data protection mode.
  4. It modifies the database configurable parameters to match the values set for the broker configuration.
  5. It generates a workload on the primary database causing log switching, and monitors the arrival rate of redo on the standby database.

Correct Answer: ABC

Section: (none)

Explanation

Explanation/Reference:

Usually Data Guard configuration verification is kind of health check of Data Guard, it does many things like performing complete health check, verifying the FSFO status, determination of protection mode, availability of standby redo log files, Data Guard status whether valid or not, After the log switch whether the sequence is shipping to standby or not and Data Guard properties. To initiate Data Guard verification Navigation is “Availability --> Verify Data Guard Configuration”.

References: http://www.toadworld.com/platforms/oracle/w/wiki/11149.monitoring-troubleshooting-data-guard-using-em12c

QUESTION 14

You created a physical standby database PRODSBY1 from the primary database PROD using SQL and RMAN. Which two are prerequisites for creating a Data Guard Broker configuration to manage these databases?

  1. The standby database must have supplemental logging enabled.
  2. The primary database must have FORCE LOGGING enabled.
  3. The DG_BROKER_START parameter must be set to TRUE for both database instances.
  4. The primary database must have supplemental logging enabled.
  5. A local net service name to enable connectivity to the PRODSBY1 database instance must be defined on the primary database host.

Correct Answer: BC

Section: (none)

Explanation

Explanation/Reference:

B: Enabled forced logging on the primary database by issuing the following command.

ALTER DATABASE FORCE LOGGING;

— Make sure at leat one logfile is present. ALTER SYSTEM SWITCH LOGFILE;

C: Enable Broker

When we have a primary database and a standby database, we need to start using the Data Guard Broker to manage them. Connect to both databases (primary and standby) and issue the following command.

ALTER SYSTEM SET dg_broker_start=true;

References: https://oracle-base.com/articles/12c/data-guard-setup-using-broker-12cr1

QUESTION 15

In which two cases is it possible to change the protection mode to maximum protection using Enterprise Manager Cloud Control?

  1. A snapshot standby database is the only standby database in the Data Guard configuration.
  2. A logical standby database is the only standby database in the data guard configuration.
  3. A far sync instance is the only Data Guard configuration member receiving redo in synchronous mode.
  4. Flashback is not enabled for either the primary database, the standby database, or both in the Data Guard configuration.
  5. The primary and standby databases are hosted on different operating systems.

Correct Answer: BE

Section: (none)

Explanation

Explanation/Reference:

Maximum protection mode requires the SYNC redo transport mode to be set on at least one standby database.

Note:

The Maximum protection mode ensures that no data loss will occur if the primary database fails. To provide this level of protection, the redo data needed to recover a transaction must be written to both the online redo log and to the standby redo log on at least one synchronized standby database before the transaction commits. To ensure that data loss cannot occur, the primary database will shut down, rather than continue processing transactions, if it cannot write its redo stream to at least one synchronized standby database.

References: http://www.oracle.com/technetwork/oem/framework-infra/wp-em12c-building-ha-level3-1631423.pdf

QUESTION 16

Which two are true about the usage of DBMS_ROLLING?

  1. The leading group contains the original primary database.
  2. The trailing group contains the original primary database.
  3. The background process DMON must be enabled on all database instances that take part in the rolling release upgrade process.
  4. At least one logical standby database must be part of the initial Data Guard configuration.
  5. The trailing group can contain standby databases that will protect the original primary database during the rolling release upgrade process.

Correct Answer: DE

Section: (none)

Explanation

Explanation/Reference:

E: The trailing group contains the original primary database and standby databases that will protect the original primary during the rolling upgrade process.

D: Databases in the leading group are upgraded first; hence the name leading group. The leading group contains the designated future primary database, and the physical standbys that you can configure to protect the designated future primary. The future primary is first converted into a logical standby database and then the new database software is installed on it and the upgrade process is run. Other standby databases in the leading group also must have their software upgraded at this point.

Note: To upgrade the database software in an Oracle Data Guard configuration in a rolling fashion, you first designate a physical standby as the future primary database.

Conceptually, the rolling upgrade process splits the Oracle Data Guard configuration into two groups: the leading group (LG) and the trailing group (TG).

Incorrect Answers:

A: The leading group contains the designated future primary database, and the physical standbys that you can configure to protect the designated future primary. References: https://docs.oracle.com/database/121/SBYDB/dbms_rolling_upgrades.htm#SBYDB5431

QUESTION 17

Which three statements are true about Far Sync instances?

  1. The Data Guard Broker must be used to deploy and manage Far Sync instances.
  2. They enable standby database to be configured at remote distances from the primary without impacting performance on the primary.
  3. A primary database can ship redo directly to multiple Far Sync instances.
  4. They use as spfile, a standby controlfile, and standby redo logs.
  5. They work with any protection level.

Correct Answer: ABD

Section: (none)

Explanation

Explanation/Reference:

A: The the far sync instance is added to a Data Guard broker configuration.

B: Creating a far sync instance is similar to creating a physical standby except that data files do not exist at the far sync instance. Therefore, on a far sync instance there is no need to copy data files or restore data files from a backup. Once the far sync instance has been created, the configuration is modified to send redo synchronously from the primary database to the far sync instance in Maximum Availability mode and the far sync instance then forwards the redo asynchronously in real time.

D: Creating and Configuring a Far Sync Instance Take the following steps to create a far sync instance:

  1. Create the control file for the far sync instance.
  2. Create a parameter file (PFILE) from the server parameter file (SPFILE) used by the primary database.
  3. Create a server parameter file (spfile) from the edited parameter file (pfile) to facilitate any subsequent changes to parameter values.
  4. Use an operating system copy utility to copy the far sync instance control file created in Step 1 and the server parameter file (spfile) created in Step 3 from the primary system to the appropriate locations on the far sync instance system.
  5. Create standby redo logs in the same way they are created for a regular standby. Etc.

Incorrect Answers:

C: A far sync instance manages a control file, receives redo into standby redo logs (SRLs), and archives those SRLs to local archived redo logs. E: A far sync instance is supported in either maximum performance or maximum availability mode only.

References: https://docs.oracle.com/database/121/SBYDB/create_fs.htm

QUESTION 18

Which three statements are true about snapshot standby databases?

  1. Tablespaces can be dropped.
  2. Tables can be dropped.
  3. The broker may be used to fail over to a snapshot standby database.
  4. A logical standby database can be converted into a snapshot standby database.
  5. Tablespaces can be created.

Correct Answer: ABE

Section: (none)

Explanation

Explanation/Reference:

Incorrect Answers:

Not C: A snapshot standby database cannot be the target of a switchover or failover. A snapshot standby database must first be converted back into a physical standby database before performing a role transition to it.

D: A snapshot standby database is a fully updatable standby database that is created by converting a physical standby database into a snapshot standby database. References: https://docs.oracle.com/cd/B28359_01/server.111/b28294/manage_ps.htm

QUESTION 19

Which three are benefits of using the Data Guard Broker to manage standby databases?

  1. It simplifies physical standby database creation.
  2. It provides an easy failover capability using a single command.
  3. It coordinates database state transitions and updates database properties dynamically.
  4. It automatically changes database properties after the protection mode for a configuration is changed.
  5. It provides an easy switchover capability using a single command.
  6. It simplifies logical standby database creation.
  7. It load balances connections between the primary and all the standby database instances that are open as read-only for reporting.

Correct Answer: BCE

Section: (none)

Explanation

Explanation/Reference:

BE: The broker simplifies switchovers and failovers by allowing you to invoke them using a single key click in Oracle Enterprise Manager or a single command at

the DGMGRL command-line interface (referred to in this documentation as manual failover).

C: The broker coordinates database state transitions and update database properties dynamically with the broker recording the changes in a broker configuration file that includes profiles of all the databases in the configuration. The broker propagates the changes to all databases in the configuration and their server parameter files.

References: https://docs.oracle.com/cd/E11882_01/server.112/e40771/concepts.ht

QUESTION 20

Which three are always benefits of using a logical standby database?

  1. It can be used for database rolling release upgrades.
  2. It can be used to replicate a single pluggable database (PDB) in a multitenant container database.
  3. It can be used as an updatable database for Real Application testing and then converted back to a standby database without affecting the updates.
  4. It can be used for reporting workloads requiring additional indexes or materialized views or both.
  5. It provides a disaster-recovery solution with switchover and failover options that can recover any data updated on the primary database.
  6. It can be used for testing patches without affecting the primary database.

Correct Answer: CDF

Section: (none)

Explanation

Explanation/Reference:

C: A logical standby database can be used to test new software releases and some kinds of applications on a complete and accurate copy of the primary’s data. It can host other applications and additional schemas while protecting data replicated from the primary against local changes.

D: A logical standby database is open read/write while changes on the primary are being replicated. Consequently, a logical standby database can simultaneously be used to meet many other business requirements, for example it can run reporting workloads that would problematical for the primary’s throughput.

F: Logical standby can be used to greatly reduce downtime associated with applying patchsets and new software releases. A logical standby can be upgraded to the new release and then switched over to become the active primary. This allows full availability while the old primary is converted to a logical standby and the patchset is applied.

References: https://docs.oracle.com/cd/E11882_01/server.112/e41134/standby.htm#SBYDB00103

QUESTION 21

Which two are prerequisites for creating a standby database using Enterprise Manager cloud control?

  1. The primary database must have FORCE LOGGING enabled.
  2. The primary database must be in archivelog mode.
  3. A backup of the primary database must exist.
  4. The primary host and the proposed standby database host must run the same operating system.
  5. The primary database instance must be started using an SPFILE.
  6. The primary database must have flashback enabled.

Correct Answer: AB

Section: (none)

Explanation

Explanation/Reference:

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

QUESTION 22

A Data Guard environment has this configuration and these attributes:

  1. The primary database prima is in the local region.
  2. A physical standby database physt1 is in the local region.
  3. A physical standby database physt2 is in a remote region.
  4. The primary ships redo to physt1.
  5. physt1 ships redo physt2.
  6. physt1 and physt2 have Real-Time Query enabled.

A sequence has been created with this SQL statement in the primary database: CREATE SEQUENCE a NOCACHE SESSION:

Which two statements are true?

  1. The sequence is usable on physt1 and physt2.
  2. The sequence is usable on physt1 but not usable on physt2.
  3. The sequence is usable on physt2 if physt1 becomes unavailable, but only if an alternative redo destination has been configured on the primary database.
  4. physt2 will no longer receive redo if physt1 becomes unavailable, unless LOG_ARCHIVE_DEST_n has the ALTERNATE attribute specified on the primary database.
  5. physt2 will no longer receive redo if physt1 becomes unavailable, unless LOG_ARCHIVE_DEST_n has the ALTERNATE attribute specified on physt1.

Correct Answer: CE

Section: (none)

Explanation

Explanation/Reference:

Note: LOG_ARCHIVE_DEST_n specifies an alternate archiving destination to be used when the original destination fails.

The ALTERNATE attribute is optional. If an alternate destination is not specified, then redo transport services do not automatically change to another destination if the original destination fails.

References: https://docs.oracle.com/cd/B28359_01/server.111/b28294/log_arch_dest_param.htm https://docs.oracle.com/database/121/SQLRF/statements_6017.htm#SQLRF01314

QUESTION 23

Which three steps are prerequisites for the creation of a physical standby database on a separate server using the RMAN active database duplication method?

  1. Set the DB_UNIQUE_NAME parameter on the primary database to a different value than that of the DB_NAME parameter.
  2. Put the primary database into archivelog mode.
  3. Startup nomount the standby database instance.
  4. Configure Oracle Net connectivity on the primary host to the standby database instance.
  5. Establish user equivalence for the database software owner between the primary host and standby host.

Correct Answer: CDE

Section: (none)

Explanation

Explanation/Reference:

C: Shut down and restart the auxiliary database instance on the destination host in NOMOUNT mode.

D: When a database must be accessed from another host, you must set up a password file and Oracle Net connectivity.

E: When instructed to connect to the necessary instances, connect to the root as a user with SYSDBA or SYSBACKUP privilege. On both instances, the password for the user performing the duplication must be the same.

References: https://docs.oracle.com/database/121/BRADV/rcmdupdb.htm

QUESTION 24

Which three are required in order to use Real-Time Query without lagging behind the primary?

  1. There must be standby redo logs on the standby database.
  2. There must be standby redo logs on the primary database.
  3. The primary must ship redo asynchronously.
  4. COMPATIBLE must be set to 11.1.0 or higher.
  5. Real-Time apply must be enabled on the standby.

Correct Answer: ADE

Section: (none)

Explanation

Explanation/Reference:

D: The COMPATIBLE database initialization parameter must be set to 11.0 or higher to use the real-time query feature of the Oracle Active Data Guard option.

E: The apply lag control and Redo Apply synchronization mechanisms require that the client be connected and issuing queries to a physical standby database that is in real-time query mode.

Incorrect Answers:

C: The standby database must receive redo data via the SYNC transport.

References: https://docs.oracle.com/cd/E11882_01/server.112/e41134/manage_ps.htm#SBYDB00707

QUESTION 25

Examine the Fast-start configuration: DGMGRL> show fast_start failover; Fast-Start Failover: ENABLED

Threshold : 30 seconds Target: sheep

Observer : 017.example.com

Lag Limit: 30 seconds (not in use) Shutdown Primary: TRUE

Auto-reinstate: TRUE Observer Reconnect: (none) Observer Override: FALSE

Configurable Failover Conditions

Health Conditions:

Corrupted Controlfile YES Corrupted Dictionary YES Inaccessible Logfile NO Stuck Archiver YES Datafile Offline YES

Oracle Error Conditions:

(none)

Which three are true?

  1. The observer will initiate a failover when the primary database is unable to produce local archived redo log files.
  2. An automatic failover will be initiated even if the target standby database lags behind the primary.
  3. The observer is running.
  4. A failover may occur if the observer has lost connectivity to the primary database, even if the Fast-Start Failover target standby database has a good connection to the primary database.
  5. The configuration operates in Maximum Availability mode.
  6. The configuration operates in Maximum Performance mode.

Correct Answer: ACE

Section: (none)

Explanation

Explanation/Reference:

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: docs.oracle.com/cd/E11882_01/server.112/e40771/sofo.htm

QUESTION 26

Which four are true about DGMGRL show command?

  1. It can be used to show properties of a pluggable standby database.
  2. It can be used to show properties of a pluggable primary database.
  3. It can be used to show instance-specific properties for a RAC database.
  4. It can be used to show properties of a far sync instance.
  5. It can be used to show Fast Start Failover properties.
  6. It can be used to show properties of a primary container database.

Correct Answer: ABEF

Section: (none)

Explanation

Explanation/Reference:

E: SHOW FAST_START FAILOVER

Displays all fast-start failover related information.

F: SHOW DATABASE

Displays information about the specified database.

Incorrect Answers:

C: This command is rejected if you use the SHOW DATABASE property-name command to show an instance-specific property in an Oracle RAC database. References: https://docs.oracle.com/cd/B28359_01/server.111/b28295/dgmgrl.htm

QUESTION 27

A customer asks you to propose the most appropriate solution for this set of requirements:

  1. We need a disaster recovery solution that enables us to fail over from our production database with zero data loss.
  2. We want to generate reports from the proposed standby database at the same time that it is used for other purposes.
  3. Developers may need to test occasionally on a copy of the live database.

You have to already confirmed that there are no unsupported data types on the primary database. Which two solutions would you recommend?

    1. a remote physical standby database with RedoRoutes via a far sync instance
    2. a snapshot standby database with synchronous redo transport
    3. a physical standby database with real-time query enabled
    4. a logical standby database
    5. a read mostly implementation of a physical standby database

Correct Answer: BC

Section: (none) Explanation

Explanation/Reference:

QUESTION 28

Which two statements are true about Real-Time Query?

  1. Setting STANDBY_MAX_DATA_DELAY =0 requires synchronous redo transport.
  2. Disabling Real-Time Query prevents the automatic start of redo apply when a physical standby database is opened READ ONLY.
  3. Real-Time Query sessions can be connected to a Far Sync instance.
  4. Real-Time Query has no limitations regarding the protection level of the Data Guard environment.
  5. A standby database enabled for Real-Time Query cannot be the Fast-Start Failover target of the Data Guard configuration.

Correct Answer: BD

Section: (none)

Explanation

Explanation/Reference:

If a license for the Oracle Active Data Guard option has been purchased, Redo Apply can be active while the physical standby database is open, thus allowing queries to return results that are identical to what would be returned from the primary database. This capability is known as the real-time query feature.

Incorrect Answers:

A: If STANDBY_MAX_DATA_DELAY is set to 0, a query issued to a physical standby database is guaranteed to return the exact same result as if the query were issued on the primary database, unless the standby database is lagging behind the primary database, in which case an ORA-3172 error is returned.

Note: The STANDBY_MAX_DATA_DELAY session parameter can be used to specify a session-specific apply lag tolerance, measured in seconds, for queries issued by non-administrative users to a physical standby database that is in real-time query mode. This capability allows queries to be safely offloaded from the primary database to a physical standby database, because it is possible to detect if the standby database has become unacceptably stale.

QUESTION 29

On your logical standby database, you specified these rules:

SQL> EXECUTE DBMS_LOGSTBY.SKIP (STMT=> ‘DML’, – SCHEMA_NAME => ‘HR’, –

OBJECT_NAME=> ‘EMP_NEW’);

SQL> EXECUTE DBMS_LOGSTBY.SKIP (STMT=> ‘DML’, – SCHEMA_NAME => ‘HR’, –

OBJECT_NAME=> ‘EMP_OLD’);

After completion of the weekend batch cycle you attempt to delete the SQL Apply filters:

SQL> EXECUTE DBMS_LOGSTBY.UNSKIP (STMT=> ‘DML’, – SCHEMA_NAME => ‘HR’, –

OBJECT_NAME=> ‘EMP%’);

Which is true regarding the execution of the UNSKIP procedure?

  1. It succeeds only if SQL apply is stopped before deleting the SQL Apply filter.
  2. It succeeds but the SQL Apply filters are not deleted.
  3. It deletes both the SQL Apply filters.
  4. It returns an error because the syntax to delete a SQL Apply filter must specify the same object names as specified when the filter was added.
  5. It succeeds only if all DML statements executed on the primary have been applied on the logical standby deleting the SQL Apply filter.

Correct Answer: D

Section: (none)

Explanation

Explanation/Reference:

The UNSKIP procedure reverses the actions of the SKIP procedure by finding the record, matching all the parameters, and removing the record from the system table. The match must be exact, and multiple skip actions can be undone only by a matching number of unskip actions. You cannot undo multiple skip actions using wildcard characters.

References: https://docs.oracle.com/cd/B12037_01/appdev.101/b10802/d_lsbydb.htm#997823

QUESTION 30

A query on the view DBA_LOGSTBY_UNSUPPORTED on your primary database returns no rows. As a result of this, you decide that an upgrade may use logical standby databases.

Which two are true about upgrading Data Guard environments consisting of one logical standby database running on a separate host from the primary?

  1. The upgrade always requires downtown until the upgrade of the logical standby is completed.
  2. Using manual upgrade, catctl.pl can be executed in some cases on the primary and standby database simultaneously.
  3. The upgrade always required downtime until the upgrade of the primary is completed.
  4. Using manual upgrade, catupgr.sql needs to run on the primary database only.
  5. SQL Apply on the local standby database must be stopped while the primary database is upgraded.
  6. Fast-Start Failover can be used to protect the primary database during the upgrade.

Correct Answer: BE

Section: (none)

Explanation

Explanation/Reference:

B (not D): Oracle Database 12c introduces the new Parallel Upgrade Utility, catctl.pl. This utility replaces the catupgrd.sql script that was used in earlier releases. Although you can still use the catupgrd.sql script, it is deprecated starting with Oracle Database 12c and will be removed in future releases. Oracle recommends database upgrades be performed with the new Parallel Upgrade Utility, catctl.pl.

E: Once the database is started in upgrade mode, only queries on fixed views execute without errors until after the catctl.pl script is run. References:

https://docs.oracle.com/database/121/UPGRD/upgrade.htm#UPGRD52867 https://docs.oracle.com/database/121/UPGRD/deprecated.htm#UPGRD60034

QUESTION 31

Your Data Guard environment consists of these components and settings:

  1. A primary database
  2. Two remote physical standby databases
  3. The redo transport mode is set to SYNC.
  4. Real-time query is enabled for both standby databases.
  5. The DB_BLOCK_CHECKING parameter is set to TRUE on both standby databases.

You notice an increase in redo apply lag time on both standby databases.

Which two would you recommend to reduce the redo apply lag on the standby databases?

  1. Increase the size of the buffer cache on the physical standby database instances.
  2. Increase the number of standby redo log files on the standby databases.
  3. Decrease the redo log file size on the primary database.
  4. Lower DB_BLOCK_CHECKING to MEDIUM or LOW on the standby databases.
  5. Increase the size of standby redo log files on the standby databases.

Correct Answer: AD

Section: (none) Explanation

Explanation/Reference:

Use Data Guard Redo Apply Best Practices

To improve the Redo Apply rate of a physical standby database (and media recovery):

  • Set DB_CACHE_SIZE to a Value Greater than on the Primary Database
  • Set DB_BLOCK_CHECKSUM=FULL and DB_BLOCK_CHECKING=MEDIUM or FULL
  • Maximize I/O Rates on Standby Redo Logs and Archived Redo Logs
  • Assess Recovery Rate
  • Assess Database Wait Events
  • Tune I/O Operations
  • Assess System Resources

References: https://docs.oracle.com/database/121/HABPT/config_dg.htm#HABPT4904

QUESTION 32

Which three types of backups taken in which situations may be used to perform restore operations to a logical standby database in a Data Guard environment?

  1. backups of data files taken on the primary database if connected to the recovery catalog where the logical standby database is registered
  2. backups of data files taken on the standby database if connected to the recovery catalog where the logical standby database is registered
  3. backups of control files taken on the primary database if connected to the recovery catalog where the logical standby database is registered
  4. backups of data files taken on the logical standby database, if not connected to a recovery catalog
  5. backups of control files taken on the logical standby database if not connected to a recovery catalog

Correct Answer: ADE

Section: (none)

Explanation

Explanation/Reference:

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

QUESTION 33

Examine the Data Guard configuration:

DGMGRL> show configuration:

Configuration –Animals Protection Mode: MaxAvailability Databases:

dogs- Primary database

sheep-Logical standby database cats- Logical standby database

Fast-Start Failover: DISABLED Configuration Status:

SUCCESS

Which three will be true after a switchover to Sheep?

  1. Cats will be an enabled logical standby database.
  2. Cats will be a disabled logical standby database.
  3. Dogs will be a logical standby database.
  4. Dogs will be a physical standby database.
  5. Sheep will be the primary database.

Correct Answer: ACE

Section: (none)

Explanation

Explanation/Reference:

A switchover is a role reversal between the primary database and one of its standby databases. A switchover guarantees no data loss and is typically done for planned maintenance of the primary system. During a switchover, the primary database transitions to a standby role, and the standby database transitions to the primary role.

References: https://docs.oracle.com/cd/B28359_01/server.111/b28295/sofo.htm

QUESTION 34

Which three are true concerning Automatic Block Media Recovery in a Data Guard environment when running an application as an ordinary Oracle user?

  1. Real Time Query must be enabled on the primary database.
  2. Real Time Query must be enabled on the physical standby database.
  3. If a physically corrupt block is discovered on a physical standby database, then a valid block image from the primary database is retrieved.
  4. If a physically corrupt block is discovered on the primary database, then a valid block image from a physical standby database is retrieved.
  5. If a physically corrupt block is discovered on a logical standby database, then a valid block image from the primary database is retrieved.
  6. If a physically corrupt block is discovered on a primary database, then a valid block image from the logically standby database is retrieved.

Correct Answer: BCD

Section: (none)

Explanation

Explanation/Reference:

B: For automatic block media recovery to work, a physical standby database must be in real-time query mode, which requires an Oracle Active Data Guard license. D: A physical standby database operating in real-time query mode can be used to repair corrupt data blocks in a primary database.

C: If corruption occurs on the primary database, blockmedia recovery is performed automatically using a good copy of the block from the standby database and vice versa.

References: https://ora600tom.wordpress.com/2013/09/07/abmr-automatic-block-media-recovery

QUESTION 35

Which two are true about offloading backups to a physical standby database in a Data Guard environment?

  1. The standby database must be registered in an RMAN catalog after the primary database has been registered.
  2. The standby database cannot be registered in an RMAN catalog if the primary database has not been registered.
  3. Backups of the standby control file taken while connected to the catalog where the database is registered, may be used to restore the control file on the primary database.
  4. The standby database must be registered in an RMAN catalog before the primary database has been registered.

Correct Answer: BC

Section: (none)

Explanation

Explanation/Reference:

Only the primary database must be explicitly registered using the REGISTER DATABASE command. You do this after connecting RMAN to the recovery catalog and primary database as TARGET.

References: https://docs.oracle.com/database/121/SBYDB/rman.htm#SBYDB4851

QUESTION 36

Which two statements are true for Data Guard environments with multi-tenant databases?

  1. Different pluggable databases within a logical standby database may have different guard statuses.
  2. The Data Guard broker automatically always opens the pluggable databases of a standby database after a role change operation.
  3. The Data Guard broker automatically opens all pluggable databases of a primary database a role change operation.
  4. The CDBDBA privilege must be used instead of the SYSDBA privilege for connections as SYS to the root container of a multi-tenant standby database.
  5. A multi-tenant standby database can have fewer pluggable databases than the primary container database.

Correct Answer: CD

Section: (none)

Explanation

Explanation/Reference:

C: If you execute a switchover or failover operation, the entire CDB undergoes the role change. D: To administer a multitenant environment, you must have the CDB_DBA role.

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

QUESTION 37

Examine the Data Guard configuration after an accidental switchover to Sheep: DGMGRL> show configuration;

Configuration –Animals

Protection Mode: MaxAvailability Databases:

sheep- Primary database

dogs- Logical standby database

cats- Physical standby database (disabled)

ORA-16795: the standby database needs to be re-created Fast-Start Failover: DISABLED

Configuration Status:

SUCCESS

Which three will be true after a switchover to Dogs?

  1. Sheep will be a disabled logical standby database.
  2. Sheep will be an enabled logical standby database.
  3. Cats will be a disabled physical standby database that can be manually enabled.
  4. Cats will be an enabled physical standby database.
  5. Dogs will be the primary database.

Correct Answer: BCE

Section: (none)

Explanation

Explanation/Reference:

QUESTION 38

Which three are among the various tasks performed by the data Guard Monitor (DMON) process?

  1. performing role transitions when switchover requests are made
  2. communicating with DMON processes in other database instances that are part of the broker configuration
  3. activating role-based services appropriately in the various database instances of the configuration, based on the database role
  4. communicating with the DMON process of the observer to monitor a primary database in case a fast start failover is required.
  5. maintaining information about all members of the broker configuration in binary configuration files

Correct Answer: ABE

Section: (none)
Explanation

Explanation/Reference:

A: Oracle Enterprise Manager Cloud Control (Cloud Control) works with the Oracle Data Guard monitor to automate and simplify the management of an Oracle Data Guard configuration.

With Cloud Control, the complex operations of creating and managing standby databases are simplified through Oracle Data Guard management pages and wizards, including:

  • A switchover operation that helps you switch roles between the primary database and a standby database.

B (not D): The Oracle Data Guard monitor process (DMON) is an Oracle background process that runs on every database instance that is managed by the broker. E: The broker’s DMON process persistently maintains information about all members of the broker configuration in a binary configuration file.

References: https://docs.oracle.com/database/121/DGBKR/concepts.htm#DGBKR050

QUESTION 39

A Data Guard environment has this configuration and these attributes:

  1. A primary database
  2. A Physical Standby Database named sbdb
  3. The configuration is in maximum availability protection mode.

Then sbdb is converted to a snapshot standby database. When two statements are true?

    1. Sdbd can still apply redo.
    2. The recovery point objective increases.
    3. The protection mode is lowered to maximum performance.
    4. The recovery time objective increases.
    5. Sbdb can still receive redo

Correct Answer: DE

Section: (none)

Explanation

Explanation/Reference:

E: A snapshot standby database receives and archives, but does not apply, redo data from a primary database.

D: Snapshot standby databases are best used in scenarios where the benefit of having a temporary, updatable snapshot of the primary database justifies additional administrative complexity and increased time to recover from primary database failures.

Note: Redo data received from the primary database is applied when a snapshot standby database is converted back into a physical standby database, after discarding all local updates to the snapshot standby database.

The data in the primary database is fully protected however, because a snapshot standby can be converted back into a physical standby database at any time, and the redo data received from the primary will then be applied.

Incorrect Answers:

A: A snapshot standby database receives and archives, but does not apply, redo data from a primary database. References: https://docs.oracle.com/cd/B28359_01/server.111/b28294/manage_ps.htm

QUESTION 40

Examine the Data Guard configuration: DGMGRL> show configuration verbose;

Configuration –Animals

Protection Mode: MaxPerformance Databases:

cats- Primary database

dogs-(*) Physical standby database sheep- Physical standby database

(*) Fast-Start Failover target Properties: FastStartFailoverThreshold = ‘30’

OperationTimeout = ‘30’ TraceLevel = ‘USER’ FastStartFailoverLagLimit = ‘30’

CommunicationTimeout= ‘180’

ObserverReconnect= ‘10’ FastStartFailoverAutoReinstate= ‘FALSE’ FastStartFailoverPmyShutdown= ‘TRUE’ BystanderFollowRoleChange= ‘none’ ObserverOverride = ‘FALSE’

Fast-Start Failover: ENABLED

Threshold: 30 seconds Target: dogs

Observer: 015.example.com Lag Limit: 30 seconds Shutdown Primary: TRUE Auto-reinstate: FALSE

Observer Reconnect: 10 seconds Observer Override: TRUE

Configuration Status: SUCCESS

Which two are true?

  1. The observer must run on host ol5.example.com and is currently not running.
  2. The observer will reinstate Sheep automatically after a failover, if required.
  3. The observer will mark another standby database as the failover target if the original failover target becomes unavailable.
  4. The observer will detect if the primary database is unable to accept new connections.
  5. The former primary database will not be reinstated automatically after a failover.

Correct Answer: BE

Section: (none)

Explanation

Explanation/Reference:

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).

Incorrect Answers:

A: The observer is running.

B: Sheep is neither the primary database, nor the failover target.

D: By default, the observer will initiate failover to the target standby if and only if ALL of the following are true:

  • observer is running
  • observer and the standby both lose contact with the primary

Note: if the observer loses contact with the primary, but the standby does not, the observer can determine that the primary is still up via the standby.

  • observer is still in contact with the standby
  • durability constraints are met
  • failover threshold timeout has elapsed

References:

http://www.oracle.com/technetwork/articles/smiley-fsfo-084973.html https://docs.oracle.com/cd/E11882_01/server.112/e40771/dbpropref.htm

QUESTION 41

You must configure an Oracle Data Guard environment consisting of:

  1. A primary database
  2. A Physical Standby Database
  3. A Snapshot Standby Database You must meet these requirements:
  4. Primary database availability should not be compromised by the availability of the standby databases.
  5. Under normal operations, transactions executed on the primary database should not commit before redo is written to disk on the primary database and on at least one standby database.

Which redo transport mode, and which protection mode should you configure to meet these requirements?

    1. SYNC AFFIRM and Maximum Protection
    2. SYNC NOAFFIRM and Maximum Protection
    3. SYNC AFFIRM and Maximum Availability
    4. SYNC NOAFFIRM and Maximum Availability
    5. ASYNC and Maximum Performance

Correct Answer: C

Section: (none)

Explanation

Explanation/Reference:

The Maximum Availability protection mode provides the highest level of data protection that is possible without compromising the availability of a primary database. Transactions do not commit until all redo data needed to recover those transactions has been written to the online redo log and to at least one synchronized standby database. If the primary database cannot write its redo stream to at least one synchronized standby database, it operates as if it were in maximum performance mode to preserve primary database availability until it is again able to write its redo stream to a synchronized standby database.

This mode ensures that no data loss will occur if the primary database fails, but only if a second fault does not prevent a complete set of redo data from being sent from the primary database to at least one standby 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.

Incorrect Answers:

D: In the case of SYNC/NOAFFIRM, in which there is no check that data has been written to disk on the standby, there may be some data loss.

A, B: The Maximum Protection mode ensures that zero data loss occurs if a primary database fails. To provide this level of protection, the redo data needed to recover a transaction must be written to both the online redo log and to at least one synchronized standby database before the transaction commits. To ensure that data loss cannot occur, the primary database will shut down, rather than continue processing transactions, if it cannot write its redo stream to at least one synchronized standby database.

Because this data protection mode prioritizes data protection over primary database availability, Oracle recommends that a minimum of two standby databases be used to protect a primary database that runs in maximum protection mode to prevent a single standby database failure from causing the primary database to shut down.

E: The Maximum Performance protection mode provides the highest level of data protection that is possible without affecting the performance of a primary database. This is accomplished by allowing transactions to commit as soon as all redo data generated by those transactions has been written to the online log. Redo data is also written to one or more standby databases, but this is done asynchronously with respect to transaction commitment, so primary database performance is unaffected by delays in writing redo data to the standby database(s).

This protection mode offers slightly less data protection than maximum availability mode and has minimal impact on primary database performance. This is the default protection mode.

References: https://docs.oracle.com/cd/B28359_01/server.111/b28294/protection.htm

QUESTION 42

Which four statements are true regarding SQL Apply filters for a logical standby database?

  1. They can be used to skip execution of DML triggers on a table while allowing the DML to execute.
  2. They can be used to skip ALTER SYSTEM and ALTER DATABASE commands.
  3. They can be used to stop SQL apply if it encounters an error.
  4. They can be used to skip all SQL statements executed on a specific pluggable database (PDB) within a standby multitenant container database (CDB).
  5. They can only be used to skip DML statements on a table.
  6. They can be used to skip ALTER TABLE commands on a specific tables.
  7. They can be used to skip CREATE TABLE commands.

Correct Answer: ACFG

Section: (none)

Explanation

Explanation/Reference:

A: The DDL fires DML triggers defined on the target table. Since the triggered DMLs occur in the same transaction as the DDL, and operate on the table that is the target of the DDL, these triggered DMLs will not be replicated at the logical standby.

C: The SKIP_ERROR Procedure specifies rules regarding what action to take upon encountering errors

F: You can specify rules to prevent application of DML and DDL changes to the specific table.

G: Use the SKIP procedure with caution, particularly when skipping DDL statements. If a CREATE TABLE statement is skipped, for example, you must also specify other DDL statements that refer to that table in the SKIP procedure. Otherwise, the statements will fail and cause an exception. When this happens, SQL Apply stops running.

Incorrect Answers:

B: ALTER SYSTEM and ALTER DATABASE commands cannot be skipped.

E: You can specify rules to prevent application of DML and DDL changes to the specific table.

References: https://docs.oracle.com/cd/E11882_01/server.112/e41134/manage_ls.htm#SBYDB4805 https://docs.oracle.com/cd/B19306_01/appdev.102/b14258/d_lsbydb.htm

QUESTION 43

You must configure an Oracle Data Guard environment consisting of:

  1. A primary database
  2. One Physical Standby Database
  3. One Logical Standby Database You must meet these requirements:
  4. Primary database availability should not be compromised by the availability of the standby databases.
  5. Under normal operations, transactions executed on the primary database should not commit before redo is written to disk on both the primary database and at least one standby database.

Which redo transport mode and which protection mode would you configure to meet these requirements?

    1. SYNC AFFIRM and Maximum Protection
    2. SYNC NOAFFIRM and Maximum Protection
    3. SYNC AFFIRM and Maximum Availability
    4. SYNC NOAFFIRM and Maximum Availability
    5. ASYNC and Maximum Performance

Correct Answer: C

Section: (none)

Explanation

Explanation/Reference:

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

Transactions do not commit until all redo data needed to recover those transactions has been written to the online redo log and to at least one synchronized standby database. If the primary database cannot write its redo stream to at least one synchronized standby database, it operates as if it were in maximum performance mode to preserve primary database availability until it is again able to write its redo stream to a synchronized standby database.

This mode ensures that no data loss will occur if the primary database fails, but only if a second fault does not prevent a complete set of redo data from being sent from the primary database to at least one standby 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.

Incorrect Answers:

D: In the case of SYNC/NOAFFIRM, in which there is no check that data has been written to disk on the standby, there may be some data loss.

A, B: The Maximum Protection mode ensures that zero data loss occurs if a primary database fails. To provide this level of protection, the redo data needed to recover a transaction must be written to both the online redo log and to at least one synchronized standby database before the transaction commits. To ensure that data loss cannot occur, the primary database will shut down, rather than continue processing transactions, if it cannot write its redo stream to at least one synchronized standby database.

Because this data protection mode prioritizes data protection over primary database availability, Oracle recommends that a minimum of two standby databases be used to protect a primary database that runs in maximum protection mode to prevent a single standby database failure from causing the primary database to shut down.

E: The Maximum Performance protection mode provides the highest level of data protection that is possible without affecting the performance of a primary database. This is accomplished by allowing transactions to commit as soon as all redo data generated by those transactions has been written to the online log. Redo data is also written to one or more standby databases, but this is done asynchronously with respect to transaction commitment, so primary database performance is unaffected by delays in writing redo data to the standby database(s).

This protection mode offers slightly less data protection than maximum availability mode and has minimal impact on primary database performance. This is the default protection mode.

References: https://docs.oracle.com/cd/B28359_01/server.111/b28294/protection.htm

QUESTION 44

Which three factors can influence the rate of redo apply on a physical standby database?

  1. the network latency between the primary and standby databases
  2. the number of archiver processes on the standby database
  3. the number and size of standby redo logs on the primary database
  4. the rate of redo generation on the primary database
  5. the number and size of standby redo logs on the standby database

Correct Answer: ABE

Section: (none)

Explanation

Explanation/Reference:

Consider using the following methods to optimize the time it takes to apply redo to physical standby databases.

  • (B) Set Parallel Recovery to Twice the Number of CPUs on One Standby Host
  • (E) During media recovery or Redo Apply, the redo log file is read, and data blocks that require redo application are parsed out. With parallel media recovery, these data blocks are subsequently distributed evenly to all recovery processes to be read into the buffer cache. The default is serial recovery or zero parallelism, which implies that the same recovery process reads the redo, reads the data blocks from disk, and applies the redo changes.

References: https://docs.oracle.com/cd/B19306_01/server.102/b14239/manage_ps.htm#BACHIBGG

QUESTION 45

You edit the DGConnectIdentifier database property using the edit database set property DGMGRL command. Which two are effects of this change?

  1. The fal_client database initialization parameter on all standby databases is updated with the new value.
  2. The service attribute of the log_archive_dest_n initialization parameter for any database referring to the specified database is updated with the new value.
  3. The fal_client database initialization parameter for the specified database is updated with the new value.
  4. The broker configuration must be disabled and then enabled to use the new connection property.
  5. The service attribute of the log_archive_dest_n initialization parameter referring to all standby databases is updated with the new value.

Correct Answer: AB

Section: (none)

Explanation

Explanation/Reference:

B: The DGConnectIdentifier configurable database property specifies the connection identifier the broker uses when making connections to a database.

The value of this property is specified in the SERVICE attribute of the LOG_ARCHIVE_DEST_n parameter when the broker configures redo transport services on the primary database.

A: The connect identifier for a database must allow all other databases in the configuration to reach it. References: https://docs.oracle.com/cd/E11882_01/server.112/e40771/dbpropref.htm#DGBKR870

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