Vce DBS-C01 Questions Latest

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Question 16

A corporation intends to migrate a 500-GB Oracle database to Amazon Aurora PostgreSQL utilizing the AWS Schema Conversion Tool (AWS SCT) and AWS Data Management Service (AWS DMS). The database does not have any stored procedures, but does contain several huge or partitioned tables. Because the program is vital to the company, it is preferable to migrate with little downtime.

Which measures should a database professional perform in combination to expedite the transfer process? (Select three.)

Options:

Use the AWS SCT data extraction agent to migrate the schema from Oracle to Aurora PostgreSQL.

For the large tables, change the setting for the maximum number of tables to load in parallel and perform a full load using AWS DMS.

For the large tables, create a table settings rule with a parallel load option in AWS DMS, then perform a full load using DMS.

Use AWS DMS to set up change data capture (CDC) for continuous replication until the cutover date.

Use AWS SCT to convert the schema from Oracle to Aurora PostgreSQL.

Use AWS DMS to convert the schema from Oracle to Aurora PostgreSQL and for continuous replication.

Question 17

A retail company uses Amazon Redshift for its 1 PB data warehouse. Several analytical workloads run on a Redshift cluster. The tables within the cluster have grown rapidly. End users are reporting poor performance of daily reports that run on the transaction fact tables.

A database specialist must change the design of the tables to improve the reporting performance. All the changes must be applied dynamically. The changes must have the least possible impact on users and must optimize the overall table size.

Which solution will meet these requirements?

Options:

Use the STL SCAN view to understand how the tables are getting scanned. Identify the columns that are used in filter and group by conditions. Create a temporary table with the identified columns as sort keys and compression as Zstandard (ZSTD) by copying the data from the original table. Drop the original table. Give the temporary table the same name that the original table had.

Run an explain plan to analyze the queries on the tables. Consider recommendations from Amazon Redshift Advisor. Identify the columns that are used in filter and group by conditions. Convert the recommended columns from Redshift Advisor into sort keys with compression encoding set to RAW. Set the rest of the column compression encoding to AZ64.

Run an explain plan to analyze the queries on the tables. Consider recommendations from Amazon Redshift Advisor. Identify the columns that are used in filter and group by conditions. Convert the recommended columns from Redshift Advisor into sort keys with compression encoding set to I_ZO. Set the rest of the column compression encoding to Zstandard (ZSTD).

Run an explain plan to analyze the queries on the tables. Consider recommendations from Amazon Redshift Advisor. Identify the columns that are used in filter and group by conditions. Create a deep copy of the table with the identified columns as sort keys and compression for all columns as Zstandard (ZSTD) by using a bulk insert. Drop the original table. Give the copy table the same name that the original table had.

Question 18

A company has deployed an e-commerce web application in a new AWS account. An Amazon RDS for MySQL Multi-AZ DB instance is part of this deployment with a database-1.xxxxxxxxxxxx.us-east- 1.rds.amazonaws.com endpoint listening on port 3306. The company’s Database Specialist is able to log in to MySQL and run queries from the bastion host using these details.

When users try to utilize the application hosted in the AWS account, they are presented with a generic error message. The application servers are logging a “could not connect to server: Connection times out” error message to Amazon CloudWatch Logs.

What is the cause of this error?

Options:

The user name and password the application is using are incorrect.

The security group assigned to the application servers does not have the necessary rules to allow inbound connections from the DB instance.

The security group assigned to the DB instance does not have the necessary rules to allow inbound connections from the application servers.

The user name and password are correct, but the user is not authorized to use the DB instance.

Question 19

A company is using an Amazon Aurora PostgreSQL DB cluster with an xlarge primary instance master and two large Aurora Replicas for high availability and read-only workload scaling. A failover event occurs and application performance is poor for several minutes. During this time, application servers in all Availability Zones are healthy and responding normally.

What should the company do to eliminate this application performance issue?

Options:

Configure both of the Aurora Replicas to the same instance class as the primary DB instance. Enable cache coherence on the DB cluster, set the primary DB instance failover priority to tier-0, and assign a failover priority of tier-1 to the replicas.

Deploy an AWS Lambda function that calls the DescribeDBInstances action to establish which instance has failed, and then use the PromoteReadReplica operation to promote one Aurora Replica to be the primary DB instance. Configure an Amazon RDS event subscription to send a notification to an Amazon SNS topic to which the Lambda function is subscribed.

Configure one Aurora Replica to have the same instance class as the primary DB instance. Implement Aurora PostgreSQL DB cluster cache management. Set the failover priority to tier-0 for the primary DB instance and one replica with the same instance class. Set the failover priority to tier-1 for the other replicas.

Configure both Aurora Replicas to have the same instance class as the primary DB instance. Implement Aurora PostgreSQL DB cluster cache management. Set the failover priority to tier-0 for the primary DB instance and to tier-1 for the replicas.