Oracle 1z0-076 Oracle Database 19c: Data Guard Administration Exam Practice Test

When issuing a "switchover to sheep;" command in a Data Guard configuration, the primary database (Dogs) transitions to a standby role, and the target standby database (Sheep) becomes the new primary database. Fast-Start Failover (FSFO) remains enabled, but its target changes according to the new roles of the databases. Since Cats is also a physical standby database, it does not become the failover target by default unless it is specified in the broker configuration. After the switchover, the original primary (Dogs) becomes the new standby database and thus the new failover target for FSFO.References:Oracle Data Guard Broker documentation provides detailed procedures and explanations of switchover operations, including how FSFO targets are affected post-switchover. This behavior is consistent across different Oracle Database versions that support Data Guard and FSFO.

• A fast recovery area must be configured (B): Flashback Database requires a fast recovery area to be set up because flashback logs are stored there. The fast recovery area is a unified storage location for all recovery-related files and activities.
• The database must be in ARCHIVELOG mode (C): Flashback Database operation relies on the ability to archive redo logs. Therefore, the database must be running in ARCHIVELOG mode for Flashback Database to be enabled.

References:

• Oracle Database Backup and Recovery User's Guide
• Oracle Data Guard Concepts and Administration Guide

When setting up a Data Guard Broker configuration for a primary database and its physical standby, the following prerequisites must be met:

• A: Oracle Net connectivity must be defined on both the primary and standby hosts to enable the respective database instances to communicate with each other.
• B: Supplemental logging is required on the primary database because it provides additional logging necessary for the standby database to be able to apply changes from the primary database accurately.
• F: The DG_BROKER_START parameter must be set to TRUE for both the primary and standby database instances. This parameter is used to start the Data Guard Broker process which manages the configuration.

Options C and D are not prerequisites for creating a Data Guard Broker configuration. Additionally, while FORCE LOGGING mode (option E) is recommended as a best practice to prevent possible data inconsistencies during media recovery, it is not a strict prerequisite for creating a Data Guard Broker configuration.

References: This guidance is based on Oracle's best practices for setting up Data Guard configurations, as found in the Oracle Data Guard Broker documentation and the Oracle Data Guard Concepts and Administration guide.

The error indicates that switching the protection mode to Maximum Protection is not possible due to the presence of a snapshot standby database in the Data Guard configuration, which cannot participate in synchronous redo transport required by the Maximum Protection mode. Therefore, the correct answer is:

• D. Cats is a snapshot standby database.

Comprehensive Detailed Explanation:In an Oracle Data Guard environment, the Maximum Protection mode requires that all redo data be transmitted synchronously to at least one standby database, ensuring no data loss even in the event of a primary database failure. However, a snapshot standby database, by its nature, allows read-write access and is temporarily disconnected from the redo stream, which makes it unable to participate in the synchronous redo transport required by Maximum Protection mode. The presence of a snapshot standby database in the Data Guard configuration thus prevents the activation of Maximum Protection mode, as it cannot guarantee zero data loss without a standby database capable of receiving redo data synchronously.

References:Oracle Data Guard documentation clearly outlines the requirements and restrictions of different protection modes, including the necessity for standby databases to participate in synchronous redo transport to enable Maximum Protection mode. The inability of snapshot standby databases to fulfill this requirement is a key consideration when planning Data Guard configurations and protection levels.

A Physical Standby Database can indeed be converted into a Logical Standby Database, providing flexibility in a Data Guard configuration. This allows for the database to switch roles and supports SQL apply operations, enabling more granular control over the data and transactions being replicated and applied. Additionally, having a configuration with a primary database and one or more physical standby databases allows for rolling upgrades to be performed. This means that each database in the Data Guard configuration can be upgraded in a phased manner, minimizing downtime and ensuring high availability during the upgrade process​​​​.

Enterprise Manager Cloud Control provides a graphical interface to manage multiple standby databases, simplify switchovers and failovers, and automate failover processes to a specified target standby database. It offers a comprehensive view and control over the Data Guard configuration, making complex operations more manageable.

DGMGRL is a command-line tool specifically designed for managing Data Guard configurations. It allows the administration of multiple standby databases, simplifies the execution of switchovers and failovers, reinstatements, and conversions to and from snapshot standby databases, and supports the automation of failover processes to a specified standby database.

Other options like RMAN, SQL*Plus, CRSCTL, SRVCTL, and GDCCTL do not provide the same level of integrated management functionality for Data Guard environments as Enterprise Manager Cloud Control and DGMGRL.

To meet the requirements of automatic failover and the highest level of protection without data loss, the combination of FASTSYNC redo transport mode and Maximum Availability protection mode is appropriate. FASTSYNC ensures that the performance impact on the primary database is minimized while still providing synchronous transport. Maximum Availability protection mode offers the highest level of data protection without compromising the availability of the primary database. In case of a network failure or a standby failure, the primary will not halt, avoiding disruption to the primary database operations.

ReferencesOracle Data Guard Concepts and Administration guide, which details the different protection modes and their respective levels of data protection and impact on database operations.

When STANDBY_FILE_MANAGEMENT is set to AUTO, the Oracle Data Guard automatically creates, deletes, and renames files on the standby database to match the changes made on the primary database. The tasks that lead to the automatic creation of files on the standby include:

• Adding a data file or creating a tablespace (C): When a new tablespace is created or a new data file is added on the primary database, the standby database automatically replicates this action, maintaining structural consistency with the primary database.
• Creating a PDB from the existing PDB within the same CDB (D): Creating a new Pluggable Database (PDB) within a Multitenant Container Database (CDB) on the primary database triggers an automatic creation of the corresponding PDB within the standby CDB.References:
• Oracle Data Guard Concepts and Administration Guide

The process of performing a rolling release upgrade in a Data Guard environment using a logical standby database generally involves these steps:

• Raise the compatibility level on both databases (1): Ensuring both the primary and logical standby databases are operating with the same and correct compatibility level is essential before starting the upgrade process.
• Upgrade the logical standby database (5): Apply the database upgrade to the logical standby first, which allows the primary database to continue serving the workload without interruption.
• Restart SQL Apply on the upgraded logical standby database (2): Once the logical standby has been upgraded, SQL Apply must be restarted to apply the redo data from the primary database, which is still running the earlier version.
• Perform a switchover to the logical standby database (4): After confirming that the logical standby database is successfully applying redo data, perform a switchover to make it the new primary database.
• Upgrade the old primary database (6): With the new primary database now in place, upgrade the old primary database (which is now the new standby) to the new Oracle Database release.
• Start SQL Apply on the old primary database (3): Finally, start SQL Apply on what is now the standby database to synchronize it with the new primary database.References:
• Oracle Data Guard Concepts and Administration Guide
• Oracle Database Upgrade Guide

• Logical standby databases allow the execution of DDL and DML operations, which makes them suitable for maintaining bitmap indexes and materialized views without affecting the performance of the primary database .
• Logical standby databases can be used for performing rolling upgrades and patching with minimum downtime, meeting another requirement .
• They also enable the testing of new application software releases against an up-to-date replica of the primary database, fulfilling the last requirement.

Other configurations involving physical standby databases or combinations of logical and physical standby databases might not meet all the specified requirements as efficiently or with the same level of performance isolation for the primary database.

In a Data Guard configuration where the protection mode is set to Maximum Availability and synchronous redo transport is enabled, if the standby destination fails to acknowledge the reception of redo within the net_timeout period, the primary database will terminate the synchronous redo transport mode connections to the standby database to protect the primary database from hanging (C). The primary database then operates in a Maximum Performance mode until the issue is resolved. This behavior ensures that the primary database can continue to process transactions even when the standby database is temporarily unavailable.

References:The Oracle Data Guard Broker documentation and Oracle Data Guard Concepts and Administration guide detail the behavior of different protection modes and the response to network timeouts, including the fallback to asynchronous redo transport to maintain primary database availability.

According to the requirements stated:

• Zero data loss must be guaranteed despite the loss of any one component: This necessitates synchronous redo transport to at least one standby database (for no data loss).
• The primary database must be protected against a regional disaster: This implies that there must be a standby database in a different region.
• Performance overhead on the primary should be minimized: This suggests that asynchronous transport should be used where possible to reduce the performance impact on the primary.
• Downtime on the primary for any reason must be kept to a minimum: This is indicative of a requirement for a fast failover mechanism, possibly with a fast-start failover (FSFO) and high availability.

Given these requirements, the appropriate option that fulfills all these is:

• Option C, where 'prima' is the primary database, 'fs1' is the Far Sync instance in the primary region, and 'physt' and 'physt2' are physical standby databases in the primary and remote regions, respectively. In this configuration:

This configuration ensures that there is zero data loss even if the primary region is completely lost, maintains performance by limiting the synchronous transport to the local region with a Far Sync instance, and has a remote standby database in a separate region for disaster recovery purposes.

References:

• Oracle Data Guard Concepts and Administration
• Oracle Data Guard Broker documentation

When enabling fast-start failover, certain conditions must be met:

• The fastStartFailoverTarget property is not set on Dogs (A): The primary database (Dogs) needs to have a fast-start failover target configured for the operation to succeed.
• The LogXptMode property is set to ASYNC on Sheep while Sheep is the target standby database (B): Fast-start failover requires synchronous redo transport (SYNC or FASTSYNC) to ensure zero data loss, which is a prerequisite for enabling the feature.
• The LogXptMode property is set to ASYNC on Dogs (D): Similar to the previous point, the primary database must be configured to use synchronous redo transport for the fast-start failover to be possible.References:
• Oracle Data Guard Broker documentation
• Oracle Database Error Messages Guide

To enable Fast-Start Failover in a Data Guard environment, the following conditions must be in place:

• The Data Guard environment must be managed by the Data Guard Broker (A): The Broker simplifies management tasks and is required to enable fast-start failover, which is an automatic failover mechanism provided by Data Guard.
• You can specify only one standby database as the fast-start failover target (C): Fast-start failover is designed to fail over to a single, predetermined standby database, known as the target standby.
• Flashback Database must be enabled on both the primary database and the Fast-Start Failover target standby database (F): Flashback Database provides a quick way to revert a database to a point in time before a logical or physical corruption or error occurred. It must be enabled on both the primary and target standby databases to allow for the possibility of reinstating the old primary as a standby after a failover.References:
• Oracle Data Guard Concepts and Administration Guide
• Oracle Database High Availability Overview

A snapshot standby database is a fully updateable standby database that is created by converting a physical standby database into a snapshot standby database. The main characteristics of a snapshot standby database include:

• B: Tablespaces can indeed be dropped in a snapshot standby database because it is updateable and allows all types of DML and DDL operations that do not conflict with the standby role.
• C: Tablespaces can be created in a snapshot standby database for the same reasons that they can be dropped; it supports all operations that do not interfere with its standby nature.
• E: Tables can be dropped in a snapshot standby database, as it is a fully updateable standby.

Options A and D are incorrect because 'FAILOVER TO' and 'SWITCHOVER TO' commands are not used with snapshot standby databases in these contexts. A failover converts a standby database into the primary role after the original primary has become unavailable, and is not a reversible role transition. Switchover is a planned role reversal between the primary database and one of its standby databases and is not applicable to snapshot standby databases in the context provided.

Option F is incorrect because a logical standby database cannot be converted into a snapshot standby database directly. A logical standby is used for different purposes such as reporting and querying with real-time data, and its structure is different from a physical standby which can be converted into a snapshot standby.

References: Oracle Data Guard Concepts and Administration guide details the operations allowed on snapshot standby databases and the processes for transitioning between physical, snapshot, and logical standby databases.

• Stop the Observer on host1 to ensure that there are no conflicts between the instances of the Observer running on different hosts.
• Update the Data Guard Broker configuration with the new hostname for the Observer. This step is crucial to redirect the Data Guard Broker to communicate with the Observer on the new host.
• Start the Observer on host2 to resume its operations in the new environment.

Disabling and re-enabling Fast-Start Failover (steps 2 and 4) are not strictly necessary for moving the Observer to a new host. These steps would be more relevant if changes to the configuration of Fast-Start Failover itself were required, which is not the case when simply relocating the Observer.

In a Data Guard environment, you can offload the backups of certain database components to a physical standby database. Incremental backups of a standby database are interchangeable with the primary database, meaning you can apply a backup taken on a standby database to a primary database and vice versa. This includes control files, data files, and archive logs. Backups of control files and nonstandby control files are interchangeable. You can restore a standby control file on a primary database and a primary control file on a physical standby database, demonstrating their interchangeability and the ability to offload control file backups to one database in a Data Guard environment​​.

Oracle Multi-tenant architecture and Data Guard have several interactions, but specific aspects hold true in such environments:

• The Data Guard broker may be used for multi-tenant databases (B): Data Guard Broker simplifies the management and monitoring of Data Guard configurations and is fully compatible with the Oracle Multi-tenant architecture, allowing for easy management of Data Guard configurations that include multi-tenant container databases (CDBs) and their pluggable databases (PDBs).
• A Data Guard environment with a multi-tenant primary database can operate in any Protection mode (E): Data Guard can be configured to operate in Maximum Performance, Maximum Availability, or Maximum Protection mode, regardless of whether the primary database is a multi-tenant database. This flexibility ensures that Data Guard can meet various data protection and availability requirements in multi-tenant environments.References:
• Oracle Data Guard Broker documentation
• Oracle Multitenant Administrator's Guide

In an Oracle Active Data Guard environment:

• B: Read-mostly reporting applications that utilize global temporary tables to store session-specific data can be effectively offloaded to an Active Data Guard standby database, reducing the load on the primary database.
• C: Sequences can be used with global temporary tables on an Active Data Guard standby database to support certain types of read-mostly applications, though some restrictions on sequence use may apply.
• E: In Oracle Database 19c and later, DML redirection allows DML operations performed on an Active Data Guard standby database to be transparently redirected to the primary database. This is part of the DML Redirection feature.

Option A is incorrect because not all PL/SQL blocks run on an Active Data Guard standby database can be redirected to the primary database. Some PL/SQL executions, specifically those that would attempt to make changes to the database, are not supported on the standby.

Option D is incorrect because DDL operations on private temporary tables are not redirected; instead, private temporary tables are session-specific and are not persisted on disk, so they do not generate redo and are not applicable to an Active Data Guard standby.

References: The behavior and capabilities of Active Data Guard standby databases are documented in the Oracle Data Guard Concepts and Administration guide and the Active Data Guard documentation.

Block change tracking is a feature that enhances the efficiency of incremental backups by recording changed blocks in a tracking file. When used with Oracle Active Data Guard:

• It starts the RVWR process on the physical standby database instance (A): When block change tracking is enabled on a physical standby database, the Recovery Writer (RVWR) process is initiated. This process is responsible for recording the changes to blocks in the block change tracking file, which is then used to optimize incremental backups.
• It allows fast incremental backups to be offloaded to the physical standby database (E): With block change tracking enabled on the physical standby database, fast incremental backups can be offloaded from the primary database. This reduces the workload on the primary database and utilizes the standby database for backup operations, improving overall system performance and efficiency.References:
• Oracle Database Backup and Recovery User's Guide
• Oracle Active Data Guard documentation