Oracle 1z0-915-1 Dumps

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.

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 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 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

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 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

The purpose of theocimds: trueoption in theutil.dumpInstancecommand is to:

D.It stores the exported files in OCI Object Storage: This option ensures that the exported database files are stored directly in Oracle Cloud Infrastructure Object Storage.

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

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.

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

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.

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

To minimize DB system downtime caused by automatic maintenance operations, you should enable high availability. High availability ensures that there are multiple instances of your database running in different fault domains or availability domains, reducing the impact of maintenance on the system's availability.

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

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

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

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

When automatic backup retention of a DB system is disabled,deleting the DB system(Answer C) will delete all automatic backups of the DB system.

Automatic Backups: These are backups created automatically by the OCI service to ensure data protection.

Backup Deletion: If automatic backups are disabled and you delete the DB system, all associated automatic backups are also deleted. This operation is irreversible, and you should ensure that necessary backups are taken before deleting the DB system.

References:

OCI MySQL Database Service Backup and Restore

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