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

Based on Oracle Database 19c: Data Guard Administration documents, the three measures that can prevent clients from connecting to the wrong database instances during switchovers, failovers, or regular operations in a Data Guard environment are:

• B. The standby database services must be defined statically with the Listeners running on the standby database hosts.
• D. The client applications must use the correct TNS entries when requesting connections to the database instances.
• E. Client TNS entries for the databases use the correct service names for the intended service.
• In an Oracle Data Guard configuration, correctly configuring Oracle Net Services (including TNS entries and listeners) is crucial for ensuring that clients connect to the appropriate database instance, whether it's the primary or standby. Defining services on the standby database and associating them with listeners ensures that client applications can connect to the standby when needed, especially useful in a role transition or when the standby is open for read-only access or real-time query. It's essential that TNS entries used by client applications specify the correct service names that correspond to the intended database roles, such as primary or standby. This setup facilitates seamless connectivity to the appropriate instance based on the role, especially critical during switchovers and failovers when the roles of the databases change.
• References:Oracle's Data Guard concepts and administration guide provides extensive information on configuring network services for Data Guard environments, ensuring that applications connect to the correct database instance based on the current role of the databases in the Data Guard configuration.

After a successful failover to the 'cats' database in a Data Guard configuration:

• B: Sheep, being another standby database, would typically remain in the enabled state unless specifically disabled or if there was a configuration issue.
• D: Dogs, which was the primary database prior to failover, will be in a disabled state as part of the failover process. Manual intervention is required to re-establish 'dogs' as a standby database or to return it to the primary role through another role transition.
• E: If the configuration was in Maximum Availability mode before failover, it would remain in this mode after failover, provided all settings were properly configured and no changes were made to the protection mode.

Option A is incorrect because failover does not automatically change the protection mode to Maximum Performance. The protection mode remains as it was prior to the failover unless manually altered.

References: The behavior of Oracle Data Guard during failover and the resulting configuration state is described in the Oracle Data Guard Broker documentation.

Data Guard Broker is a management tool that simplifies the configuration, management, and monitoring of Data Guard environments. The prerequisites for using Data Guard Broker include:

• The primary and standby databases must run the same version of the Oracle Database server (A): This ensures compatibility between the primary and standby databases and enables seamless role transitions and data synchronization.
• Network connectivity to the primary database instance must be defined on the servers hosting the standby database instances (B): Proper network connectivity is essential for communication between the primary and standby databases, allowing for the replication of data and the synchronization of changes.
• If any database in the configuration is a RAC database, then the broker configuration files must reside in shared storage accessible by all database instances for all databases in the broker configuration (D): In Real Application Clusters (RAC) environments, shared storage ensures that all instances of the RAC database can access the broker configuration files, facilitating the management of the Data Guard environment across all instances.References:
• Oracle Data Guard Broker documentation
• Oracle Real Application Clusters Administration and Deployment Guide