Free Oracle 1z0-076 Practice Exam with Questions & Answers

Asynchronous redo transport is a method where the primary database does not wait for an acknowledgment from the standby database before committing transactions, which helps in minimizing the impact on the primary database's performance (B). This transport mode is associated with the Maximum Performance data protection mode, which prioritizes performance over synchronicity of data between the primary and standby databases (C). While it provides a level of data protection, there could be some data loss in the event of a primary database failure because redo data may not have been transmitted to the standby database at the time of the failure.

The ORA-03172: STANDBY_MAX_DATA_DELAY error indicates that the real-time query on the physical standby database is experiencing delays beyond the specified maximum data delay threshold. Increasing the network bandwidth (Option E) can enhance the speed at which redo data is transferred from the primary to the standby database, thereby reducing the likelihood of exceeding the STANDBY_MAX_DATA_DELAY threshold. Reducing I/O latency on the primary database's storage (Option B) ensures that redo data is generated and shipped more efficiently, further mitigating the risk of delay. These actions, focused on optimizing data transfer and processing speed, address the root causes of the ORA-03172 error in a synchronous Data Guard configuration operating in Maximum Availability mode.

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.

To automate the instantiation of a PDB in the standby database after creating a remote clone in the primary database, certain conditions must be met:

Open PDBI (remote clone source) in Read Only (A):The source PDB from which the clone is created must be open in read-only mode to ensure a consistent state during cloning.

Set STANDBY_PDB_SOURCE_FILE_DIRECTORY to <location of the PDB> in the london database (C):This parameter specifies the location on the standby database where the files from the source PDB should be placed.

A Far Sync instance is a special kind of Oracle Data Guard configuration that allows synchronous redo transport from a primary database to a remote standby database with minimum impact on the primary database's performance. The Far Sync instance receives redo data synchronously from the primary database (A), then ships it asynchronously to the remote standby database, thus extending zero data loss protection over longer distances and higher network latency environments than would be practical with a synchronous standby alone. The Far Sync instance does not apply the redo data; it just receives and ships it (E). A Far Sync instance does not have data files, and it cannot apply redo to stay synchronized with the primary database.

D. The database role indicated byFS_FAILOVER_STATUSas BYSTANDER implies that the database is a standby database in the Data Guard configuration. This means the database is neither a primary database nor an active failover target.

E. Since theFS_FAILOVER_OBSERVER_HOSTcolumn showscats, it suggests that this is the host on which the observer would run. However, because theFS_FAILOVER_OBSERVER_PRESENTcolumn is not shown, we cannot definitively state if the observer is currently connected or not. IfFS_FAILOVER_OBSERVER_PRESENTis 'YES', the observer is connected, if 'NO', then it's not. In the absence of this column's output, the best assumption based on the available data is that the observer is not connected.

The output shows that theFS_FAILOVER_STATUSisBYSTANDER, which indicates that the database in question is not actively involved in a fast-start failover configuration as a primary or standby. It is in a bystander role, meaning that while it is part of a Data Guard configuration, it is neither a target for failover nor actively participating in failover operations. Additionally,FS_FAILOVER_OBSERVER_HOSTshows 'cats', which indicates the host where the observer process is expected to run. However, since there is no information about the observer being present, we can infer that although 'cats' is designated for the observer to run, the observer is not currently connected to this database.

References

Oracle documentation on Data Guard configurations and theV$DATABASEview which provides information about the fast-start failover status and observer host.

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​​​​.

Far Sync instances are a feature of Oracle Data Guard designed to support zero data loss protection over long distances:

The Data Guard Broker must be used to deploy and manage Far Sync instances (A):Data Guard Broker simplifies the deployment and management of Far Sync instances, which are an integral part of zero data loss protection configurations.

They enable standby databases to be configured at remote distances from the primary without impacting performance on the primary (C):Far Sync instances are designed to receive redo from the primary database and then forward it to a remote standby database, thereby avoiding any performance impact on the primary database itself.