Oracle 1z0-915-1 MySQL HeatWave Implementation Associate Rel 1 Exam Practice Test

When creating a Bastion service to connect to a MySQL DB system, the following are true:

The Bastion CIDR block allowlist must include the IP address of all valid client machines(Answer C): This ensures that only the IP addresses specified in the allowlist can access the Bastion service, enhancing security by restricting access to known clients.

The Bastion subnet must have an ingress rule to allow stateful connections on the MySQL DB system port number(Answer E): This allows the Bastion service to communicate with the MySQL DB system by permitting traffic through the necessary ports.

References:

OCI Bastion Service Documentation

Setting Up Bastion with MySQL DB System

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

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.

Data loaded into a MySQL HeatWave cluster:

B.Data is partitioned across cluster nodes for scalability: This allows the system to distribute the workload and handle large datasets efficiently. D.Data is stored in hybrid columnarformat to speed up analytic queries: The hybrid columnar format optimizes storage and speeds up query performance, especially for analytic workloads.

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

Before deleting a DB system in Oracle Cloud Infrastructure (OCI), you mustdisable delete protection if it is enabled(Answer C). Delete protection is a feature that prevents accidental deletion of DB systems. If enabled, it must be turned off before the DB system can be deleted.

Steps:

Navigate to the DB system in the OCI Console.

Check if delete protection is enabled.

If enabled, disable it by updating the DB system settings.

Proceed with deleting the DB system.

References:

OCI Console Documentation on DB System Management

MySQL Database Service Documentation

To create a connection in Database Tools to use the SQL Worksheet feature, the following steps are required:

Create an OCI password(Answer A): This password is necessary for authentication when connecting to the MySQL DB system.

Create an OCI secret(Answer D): Secrets are used to store sensitive information like passwords securely. The secret will contain the database credentials.

Import an X.509 certificate into the OCI vault(Answer E): This certificate is required for secure connections to the database, ensuring encrypted communication.

References:

OCI Database Tools Documentation

Using OCI Secrets

X.509 Certificates Documentation

When creating a custom configuration for the MySQL DB system in OCI Console, you can set the following:

A.Shape: This defines the compute resources (CPU, memory) allocated to the DB system. B.VCN (Virtual Cloud Network): This defines the network in which your DB system will be placed. E.Compartment: This is an OCI resource management feature that allows you to organize and isolate your cloud resources.

A.Reduce query latency: By distributing read queries across multiple replicas, the load on the primary instance is reduced, which can decrease query latency. D.Scale read queries: Read replicas allow scaling of read operations by providing additional instances to handle read queries, improving overall performance and throughput.

In MySQL HeatWave configurations, dynamic variables can be changed without requiring the configuration to be copied to a new configuration. This allows for more flexible and immediate adjustments to system settings without the need for a server restart or creating a new configuration instance.

Two methods to import data into a MySQL DB system using MySQL Shell are:

A.util.importTable(): This utility imports data from a file into a table. D.util.loadDump(): This utility loads a previously dumped database or table into a MySQL DB system.

To enable client applications to connect to a MySQL DB system that uses default port numbers and is attached to a subnet, you need tocreate an ingress rule that allows stateful connections on port 3306 and 33060(Answer C).

Ingress Rule: An ingress rule specifies the types of inbound connections that are allowed to a resource within a subnet.

Stateful Connections: Stateful connections keep track of the state of network connections passing through them, allowing return traffic to pass automatically.

Steps:

Navigate to the Virtual Cloud Network (VCN) in the OCI Console.

Open the subnet to which the MySQL DB system is attached.

Add an ingress rule to the subnet's security list to allow traffic on port 3306 (MySQL) and 33060 (MySQL X Protocol).

Ensure the rule is stateful to maintain the connection state.

References:

OCI Networking Documentation

MySQL X Protocol Documentation

To use the point-in-time recovery feature in a DB system,automatic backupsmust be enabled (Answer B).

Point-in-Time Recovery: This feature allows you to restore your database to a specific point in time, which is crucial for recovering from accidental data loss or corruption.

Automatic Backups: These provide the necessary backup data that can be used to restore the database to the desired point in time.

References:

OCI MySQL Database Service Point-in-Time Recovery

Automatic Backups Documentation

The MySQL HeatWave AutoML routine that evaluates a model isML_SCORE. This routine scores a trained machine learning model on a new dataset and evaluates its performance.

If you cannot connect directly to the MySQL DB system endpoint from your workstation connected to the Internet, the reason is thatMySQL DB system endpoint does not have a public IP address(Answer B).

Private Subnet: The MySQL DB system is provisioned in a private subnet, which means it is not directly accessible from the Internet.

Network Accessibility: To access the DB system, you need to establish a secure connection via a VPN, FastConnect, or SSH tunnel.

References:

Connecting to a MySQL DB System

OCI Networking Documentation

To offload the second query to the HeatWave cluster for execution, you can use the following methods:

SET use_secondary_engine=FORCED(Answer A): This forces the use of the HeatWave secondary engine for query execution, regardless of the estimated cost.

SET secondary_engine_cost_threshold=1000(Answer B): This lowers the cost threshold for queries to be offloaded to the HeatWave cluster, allowing queries with lower estimated costs to be offloaded.

Steps:

Before running the second query, executeSET use_secondary_engine=FORCED;to force the offloading of queries to HeatWave.

Alternatively, executeSET secondary_engine_cost_threshold=1000;to adjust the cost threshold, making the second query eligible for offloading.

Given the SSH command sets up port forwarding from the local port3311to the remote MySQL DB system port3306, the correct command to connect to the MySQL DB system from the client machine is:

C.mysqlsh mysql://admin@127.0.0.1:3311

This command connects to the local machine's port3311, which forwards the connection to the MySQL DB system at10.10.1.187:3306.

Initialization variables(Answer A) cannot be modified in MySQL custom configurations. These variables are set at the start of the MySQL service and are not changeable without restarting the service.

Initialization variables are parameters that define how the MySQL server initializes.

Changes to these variables require restarting the MySQL server to take effect.

Examples include variables likeinnodb_buffer_pool_size, which determine memory allocation settings on startup.

References:

MySQL Configuration Variables Documentation

To change the configuration of an active stand-alone DB system that is configured as the target of a channel, and the channel is currently active, you must:

D.Stop the channel, edit the DB system, change the configuration, and start the channel: This sequence ensures that no data inconsistency or replication issues occur while the configuration changes are being applied.