Free Practice Questions for Oracle 1z0-915-1 Exam

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

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.

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

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 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.

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

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