Free Oracle 1z0-915-1 Practice Exam with Questions & Answers | Set: 2

When high availability is enabled for a stand-alone DB system,the DB system has three instances running in different availability or fault domains(Answer D).

High Availability Configuration: This setup involves creating multiple instances of the DB system across different availability or fault domains to ensure redundancy and minimize the risk of downtime due to hardware or network failures.

Instances: Typically, there are three instances—one primary and two replicas—ensuring that the system can failover seamlessly if one instance goes down.

References:

OCI MySQL High Availability

To migrate an on-premises MySQL database to a MySQL DB system on OCI with the least amount of application downtime,use inbound replication to synchronize the MySQL database transactions to the DB system(Answer C).

Inbound Replication: This method involves setting up replication from your on-premises MySQL database to the MySQL DB system in OCI. This ensures that all changes and transactions are continuously replicated, keeping the DB system up to date with minimal downtime.

Steps to Implement:

Set up the MySQL DB system in OCI.

Configure the on-premises MySQL database as the master and the OCI DB system as the slave.

Start the replication process to keep the DB system synchronized with the on-premises database.

When ready, switch the application to the DB system with minimal downtime as the data is already synchronized.

References:

MySQL Replication Documentation

OCI MySQL Database Service Replication

When training a classification model with MySQL HeatWave AutoML, the following requirements must be met:

The target column and all feature columns must be stored in a single table(Answer B): All data necessary for training the model should be in one table to simplify the data processing and training pipeline.

The target column must have at least two distinct values(Answer E): For classification tasks, the target column must have multiple distinct values to enable the model to differentiate between classes.

References:

MySQL HeatWave AutoML Documentation

MySQL HeatWave User Guide

When you perform a switchover of a high-availability DB system with an attached HeatWave cluster, theHeatWave cluster is attached to the new primary instance(Answer B). This ensures continuous operation and access to the HeatWave cluster's capabilities without the need to delete or re-create the cluster.

During a switchover, the system promotes the standby instance to the primary role.

The HeatWave cluster, which was previously attached to the original primary instance, is now re-attached to the new primary instance.

This allows the new primary instance to continue processing queries using the HeatWave cluster seamlessly.

References:

MySQL HeatWave High Availability Documentation

Before enabling a MySQL HeatWave cluster,you must create a DB system with a HeatWave shape(Answer D). The HeatWave shape includes the necessary resources and configuration to support the HeatWave in-memory query accelerator.

Steps:

Create a MySQL DB system in OCI Console.

Choose a HeatWave shape during the DB system creation process.

Once the DB system is created, you can enable and configure the HeatWave cluster.

References:

MySQL HeatWave Documentation

The MySQL usermysql.sysis a reserved username used by the system for internal purposes. It cannot be used as a customer-defined user account to prevent conflicts with the system operations and maintain the integrity of the database's internal workings.

When a DB system has been successfully deleted, the following operations are allowed:

Restore the DB system from an existing manual backup(Answer C): Even after the DB system is deleted, you can restore it from any existing manual backups. This allows you to recover the data and configuration from a point-in-time backup.

View the API call logs on the Audit page(Answer E): You can view the API call logs related to the deleted DB system on the Audit page. These logs provide a record of actions taken on the DB system, including the deletion event.

References:

OCI Backup and Restore Documentation

OCI Audit Documentation

When changing the storage size of a DB system,you cannot decrease the DB system's storage size(Answer B). This restriction ensures data integrity and prevents potential data loss that could occur if the storage size were reduced.

You can only increase the storage size of the DB system.

The storage increase is done online without shutting down the DB system, allowing for uninterrupted operations.

References:

OCI MySQL DB System Scaling Documentation

You can determine the uptime of a DB system bychecking the DB system details in the OCI Web console(Answer B). The console provides information on the system status, including the uptime since the last start.

Steps:

Log in to the OCI Web console.

Navigate to the MySQL DB system.

View the details page of the DB system, where the uptime information is displayed.

References:

OCI Console Documentation

Monitoring DB System Uptime