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

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.

When creating a new DB system with data import, the following conditions apply:

The data must be stored in an Object Storage bucket in the same OCI region as the new DB system(Answer C): This ensures that the data is readily accessible and can be efficiently imported into the new DB system.

A valid pre-authenticated request must be provided to access the data(Answer D): This allows secure access to the data stored in the Object Storage bucket without needing to handle credentials directly.

References:

OCI Object Storage Documentation

Pre-Authenticated Requests Documentation

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

B.ENGINE=csv SECONDARY_ENGINE=lakehouse ENGINE_ATTRIBUTE=’{"file": [{"region": "us-ashburn-1", "namespace": "mytenant", "bucket": "bucket01", "name": "airport.csv"}] }’: This table option defines a Lakehouse external table based on a CSV file. It specifies thecsvengine for the table and uses thelakehouseas the secondary engine, along with the file's location details in OCI Object Storage.

When creating a replication channel and selecting "Source cannot use GTID auto-positioning", it typically indicates that the source's GTID mode is off. GTID (Global Transaction Identifier) auto-positioning allows for automated recovery and positioning of transactions in replication, but it requires that GTID mode be enabled on the source database.

A query may not be offloaded to the HeatWave cluster for execution due to the following reasons:

A.Theuse_secondary_enginesession variable is OFF: This setting controls whether queries should be offloaded to the secondary engine (HeatWave). B.The client is connected to the DB system instead of the HeatWave cluster: For queries to be offloaded, the client must be connected to the HeatWave cluster. E.A required column is excluded from the RAPID secondary engine: If a necessary column is not available in the HeatWave (RAPID) secondary engine, the query cannot be offloaded.

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.

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.

To enable high availability for a stand-alone DB system, the following conditions are required:

The DB system must be active(Answer D): The DB system needs to be in an active state to enable high availability features.

The DB system automatic backup must be enabled(Answer E): Automatic backups must be enabled to ensure data protection and facilitate failover operations.

Steps:

Ensure the DB system is running and operational.

Enable automatic backups through the OCI Console or API.

References:

MySQL High Availability Documentation

Automatic Backups 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.

To connect to a MySQL DB system using MySQL Shell, you can use several command-line formats. Here, we will analyze the provided options:

A.mysqlsh -h 10.0.1.221 -u admin -p MySQL8.0

Incorrect format. The password should not be directly placed after the-pflag without a space or equals sign.

B.mysqlsh mysql://MySQL8.0:admin@10.0.1.221

Incorrect format. The username should come before the password in the URL.

C.mysqlsh mysql://admin:MySQL8.0@10.0.1.221

Correct format. This is a valid way to connect using a URL-like format whereadminis the username,MySQL8.0is the password, and10.0.1.221is the host.

D.mysqlsh -h10.0.1.221 -uadmin -pMySQL8.0

Correct format. This is a valid way to connect using flags, with no spaces between the flags and their values.

E.mysqlsh -host 10.0.1.221 -user admin -password MySQL8.0

Incorrect format. MySQL Shell uses-h,-u, and-pfor specifying host, username, and password respectively.

For a MySQL DB system with five active read replicas and a workload consisting mostly of reads, the fastest query response time is achieved by:

C.Connect to the read replica load balancer to perform read-only operations: The read replica load balancer distributes the read workload across all replicas, optimizing performance and response time.

To replicate data from an on-premises MySQL server to a MySQL DB system running in Oracle Cloud Infrastructure (OCI), where the DB system is connected to a private subnet of a Virtual Cloud Network (VCN), you need to enable the DB system to communicate with the Internet securely. The correct configuration is tocreate a NAT gateway in the VCN and configure the DB system subnet to route Internet-bound traffic to the NAT gateway(Answer D).

NAT Gateway: A Network Address Translation (NAT) gateway enables instances in a private subnet to initiate outbound traffic to the Internet, but it prevents the Internet from initiating connections to those instances.

Route Table Configuration: You need to update the route table for the private subnet to direct traffic destined for the Internet to the NAT gateway.

Steps:

Create a NAT gateway in the OCI Console.

Update the route table associated with the private subnet to include a route rule that directs all Internet-bound traffic (0.0.0.0/0) to the NAT gateway.

References:

OCI NAT Gateway Documentation

Configuring Routing for Private Subnets

Automatic DB system version upgrades in OCI are performed to the next release in sequence. This means that the system is upgraded to the next available version rather than skipping to the most recent release, ensuring a stable and tested upgrade path.

For a read replica on a DB system,it must have at least 64 GB of memory(Answer D). This requirement ensures that the read replica has sufficient resources to handle read operations and maintain performance consistency with the primary DB system.

References:

OCI MySQL Read Replicas Documentation

When restoring the backup of a stand-alone DB system to a new DB system, the following changes are allowed:

Use a different subnet for the new DB system(Answer B): You can select a different subnet within the same VCN or a different VCN for the new DB system, providing flexibility in network configuration.

Use a different shape for the new DB system(Answer C): You can choose a different compute shape for the new DB system, allowing you to scale the compute resources according to the requirements.

References:

OCI MySQL Database Service Backup and Restore Documentation

To speed up the data load into a DB system usingMySQL Shell util.loadDump(), you can use thedeferTableIndexes: alloption (Answer D). This option defers the creation of indexes until after the data has been loaded, which can significantly improve the speed of the loading process.

Steps:

Export your data using MySQL Shell dump utility.

Useutil.loadDump()to import the data and specify thedeferTableIndexes: alloption.

The data is loaded without building indexes initially, reducing the time required for the import.

After the data load is complete, indexes are created in a batch process, which is more efficient than creating them during the data load.

References:

MySQL Shell Dump & Load Documentation

When exporting data to Object Storage withMySQL Shell util.dumpInstance,you must specifyociParManifest: true(Answer B). This option creates a pre-authenticated request (PAR) manifest file, which allows for secure access and upload to Object Storage without requiring direct credentials.

References:

MySQL Shell Documentation

OCI Object Storage Documentation

The following are true about the read replica load balancer:

It distributes connections among the source DB system and all read replicas(Answer B): The load balancer distributes incoming read traffic across all read replicas and the source DB system to balance the load and improve performance.

It distributes connections among read replicas(Answer E): The load balancer ensures that read traffic is evenly distributed among all available read replicas, providing high availability and scalability for read operations.

References:

OCI MySQL Database Service Read Replicas Documentation