1z0-915-1 MySQL HeatWave Implementation Associate Rel 1 Questions and Answers

To prepare data for a new DB system with data import in OCI, you shouldexport the data into an Object Storage bucket with a MySQL Shell dump utility(Answer B). This method allows you to store the data in a scalable and durable object storage service before importing it into the new DB system.

Steps:

Use MySQL Shell dump utility to export the data.

Save the export files to an Object Storage bucket in OCI.

Import the data from the Object Storage bucket into the new DB system.

References:

MySQL Shell Documentation

OCI Object Storage Documentation

In a high-availability DB system, the placement of primary and secondary instances should ensure redundancy across different availability domains (ADs) and fault domains (FDs) to minimize downtime and data loss. The placement mentioned in option D is not valid because itplaces the primary and secondary instances in the same availability domain and fault domain, which does not provide high availability.

Based on the provided SQL statements, the following two are true:

The data placement key of the airport table is airport_id(Answer A): The primary keyairport_idis used as the data placement key in theairporttable. This means that the data in the table is organized based on theairport_idvalues.

The data of the airport table is loaded into the MySQL DB system(Answer D): TheALTER TABLE airport SECONDARY_LOAD;statement successfully loads the data from the specified object storage file into the MySQL DB system.

References:

MySQL HeatWave Documentation

MySQL Engine Attributes

To determine whether a query is offloaded to the HeatWave cluster for execution,check the value of therapid_query_offload_countglobal status variable(Answer B).

rapid_query_offload_count: This variable indicates the number of queries that have been offloaded to the HeatWave cluster. By checking its value before and after running the query, you can determine if the query was offloaded.

Steps:

Connect to the MySQL DB system.

RunSHOW GLOBAL STATUS LIKE 'rapid_query_offload_count';before and after executing the query to see if the count increases, indicating offloading.

References:

MySQL HeatWave Documentation

Monitoring HeatWave Status Variables

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 creating a new MySQL DB system in the OCI Console, you have the following options:

High availability(Answer A): This option allows you to create a DB system that can automatically fail over to a standby instance in case of hardware or software failure, ensuring minimal downtime.

Standalone server(Answer C): This option lets you create a DB system with a single instance, suitable for workloads that do not require high availability or read replicas.

References:

OCI MySQL Database Service Documentation

MySQL High Availability

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.

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

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 performing a node estimate while adding a HeatWave cluster to a DB system in OCI Console, the process undertakes the following tasks:

Estimate the number of OCPUs required to process selected user tables(Answer B): The node estimation process calculates the necessary OCPUs based on the size and complexity of the tables selected by the user. This ensures that the cluster has adequate processing power for efficient performance.

Estimate the memory required for each user table(Answer C): This task involves determining the memory requirements for each table that will be loaded into the HeatWave cluster. This ensures that there is sufficient memory to handle the data and execute queries efficiently.

References:

OCI Console Documentation on HeatWave

MySQL HeatWave User Guide

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

When creating a channel for replication in MySQL, the following must be provided:

Channel name(Answer A): The unique identifier for the replication channel.

Source connection SSL mode(Answer B): Specifies the SSL mode for the connection to the source server.

Source connection password(Answer D): The password for the source server connection.

Steps:

UseCHANGE MASTER TOcommand to set up the replication channel.

Provide the channel name, SSL mode, and connection password as part of the configuration.

References:

MySQL Replication Documentation

Setting Up Replication Channels

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

To determine the version of MySQL running on your DB system, you can use the following SQL statements:

SELECT @@version;(Answer B): This query retrieves the MySQL server version from the system variables.

SHOW VARIABLES LIKE 'version';(Answer C): This query displays the server version along with other related version variables.

Steps:

Connect to your MySQL DB system.

Execute eitherSELECT @@version;orSHOW VARIABLES LIKE 'version';to retrieve the version information.

References:

MySQL Server Version Information

SHOW VARIABLES Syntax

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

The statementsCALL sys.ML_TRAIN(‘ml_data.iris’, ‘class’, NULL, @model);andSELECT @model;are used to create and retrieve a machine learning model in MySQL HeatWave AutoML. The following are true:

The generated model handle is shown in the output(Answer B): After training the model, the handle (identifier) for the model is stored in the@modelvariable and can be retrieved with theSELECT @model;statement.

The statements create a classification model(Answer C): TheML_TRAINprocedure is used to create a classification model since the target column (class) indicates a classification problem.

The target column is class(Answer E): The second argument in theML_TRAINcall specifies the target column for the machine learning model, which isclassin this case.

References:

MySQL HeatWave AutoML Documentation

ML_TRAIN Procedure Documentation