DBS-C01 Practice Test 44 — 15 Questions

Question 1

A company is migrating a 2 TB Oracle database to Amazon RDS for Oracle. The database has a large number of stored procedures, triggers, and functions. The company wants to minimize changes to the application code. Which AWS service should be used to assess and convert the database schema?

Accepted Answer

AWS Schema Conversion Tool (SCT). AWS SCT is specifically designed to assess and convert database schemas, including stored procedures, to Amazon RDS. DMS focuses on data migration. CloudEndure is for server migration. CodeCommit is for code versioning.

Answer

AWS Database Migration Service (DMS)

Answer

AWS CloudEndure Migration

Answer

AWS CodeCommit

Question 2

A company is migrating a 2 TB Oracle database to Amazon Aurora PostgreSQL. They need to minimize downtime and ensure data consistency. Which migration strategy should they use?

Accepted Answer

Use AWS DMS with ongoing replication (change data capture) from Oracle to Aurora.. Option C is correct because AWS DMS with ongoing replication allows continuous data sync, minimizing downtime. Option A is wrong because exporting to CSV and importing is manual and not suitable for minimal downtime. Option B is wrong because native PostgreSQL pg_dump/pg_restore requires downtime. Option D is wrong because S3 transfer is for file-based data, not live databases.

Answer

Use AWS DMS with full load only, then cut over during a maintenance window.

Answer

Export the database to Amazon S3 using Oracle Data Pump, then import into Aurora.

Answer

Use pg_dump to export the database and pg_restore to import into Aurora.

Question 3

A company is migrating a 500 GB Oracle database to Amazon RDS for Oracle. They need to validate the migration and ensure data consistency. Which TWO methods should they use?

Accepted Answer

Use AWS DMS data validation feature.. Options B and D are correct. AWS DMS provides data validation, and comparing row counts and checksums can verify consistency. Option A is wrong because CloudWatch does not validate data. Option C is wrong because querying random rows is not comprehensive. Option E is wrong because S3 inventory is unrelated to database consistency.

Answer

Use Amazon S3 inventory reports on the exported data.

Answer

Run random SELECT queries on a subset of tables.

Answer

Use Amazon CloudWatch Logs to compare database logs.

Question 4

A company is migrating a 100 GB MySQL database to Amazon Aurora MySQL. The migration must have minimal downtime and the source database is currently in use. Which approach should the company take?

Accepted Answer

Use AWS DMS with ongoing replication from the source MySQL database to Aurora.. Creating an Aurora Replica from a MySQL dump is not possible; Aurora Replicas can only be created from an existing Aurora instance. Using DMS with ongoing replication allows minimal downtime. mysqldump requires downtime. Backup and restore also requires downtime.

Answer

Create an Aurora Replica from the on-premises MySQL database and promote it.

Answer

Export the database using mysqldump and import it into Aurora during a maintenance window.

Answer

Take a physical backup of the MySQL database, upload to S3, and restore to Aurora.

Question 5

A financial services company is migrating a 500 GB Oracle database to Amazon Aurora MySQL-Compatible Edition. The migration must have minimal downtime and support bidirectional replication for a test-and-cutover approach. The company currently uses Oracle GoldenGate for replication. Which migration strategy should be used?

Accepted Answer

Use AWS DMS with a full load and ongoing replication from Oracle to Aurora MySQL, then cut over.. Option C is correct because AWS DMS supports ongoing replication from Oracle to Aurora MySQL, enabling a test-and-cutover approach with minimal downtime. Option A is wrong because the AWS Schema Conversion Tool (SCT) does not handle data replication. Option B is wrong because AWS DMS supports cross-engine migrations from Oracle to Aurora MySQL. Option D is wrong because AWS DMS cannot use Oracle GoldenGate as a source; GoldenGate is a separate replication tool that is not directly integrated.

Answer

Use AWS Schema Conversion Tool (SCT) to convert the schema and then use AWS DMS for a one-time full load.

Answer

Use AWS DMS with Oracle GoldenGate as a source for continuous replication to Aurora MySQL.

Answer

Use Oracle GoldenGate to replicate directly to Aurora MySQL, then cut over.

Question 6

A company wants to migrate an on-premises MySQL database to Amazon RDS for MySQL. The database is 500 GB and experiences heavy write traffic. They need to minimize downtime and ensure no data loss. Which approach should they take?

Accepted Answer

Set up MySQL replication from the on-premises database to RDS, then promote the RDS instance when ready.. Option D is correct because setting up MySQL replication from on-premises to RDS allows near-zero downtime migration. Option A is wrong because a dump and reload requires the source to be read-only. Option B is wrong because AWS DMS with full load only does not capture ongoing changes. Option C is wrong because creating a read replica from on-premises is not supported; RDS read replicas are only for RDS instances.

Answer

Use AWS DMS with a full load task, then cut over the application to RDS.

Answer

Create an RDS read replica of the on-premises database, then promote it to a standalone instance.

Answer

Use mysqldump to export the database and mysql command to import into RDS during a maintenance window.

Question 7

A company is migrating a PostgreSQL database to Amazon Aurora PostgreSQL. They want to use the AWS DMS for the migration. Which THREE resources need to be created in the AWS account?

Accepted Answer

DMS target endpoint pointing to Aurora PostgreSQL.. Options A, B, and D are correct. DMS requires a replication instance, source endpoint, and target endpoint. Option C is wrong because a CloudFormation stack is not required. Option E is wrong because a load balancer is not needed for DMS.

Answer

Application Load Balancer for the replication instance.

Answer

AWS CloudFormation stack to provision resources.

Question 8

A company is migrating a 1 TB PostgreSQL database from on-premises to Amazon RDS for PostgreSQL. The migration must have minimal downtime. Which TWO steps should be taken to achieve this?

Accepted Answer

Configure AWS DMS with ongoing replication from the source to the target.. DMS with ongoing replication enables minimal downtime by continuously syncing changes. Using pglogical to replicate changes is another approach. Option B (importing a backup) causes downtime. Option D (creating a read replica) is not possible from on-premises. Option E (SCT for schema conversion) may be needed but not for minimal downtime.

Answer

Use AWS SCT to convert the schema to Amazon Aurora.

Answer

Take a full backup using pg_dump and import it into RDS during a maintenance window.

Answer

Create an RDS Read Replica of the on-premises database.

Question 9

A company is deploying a new web application that uses Amazon RDS for MySQL. The application must be highly available across three Availability Zones with automatic failover. Which deployment configuration should be used?

Accepted Answer

Deploy Amazon Aurora MySQL with three Aurora Replicas in different Availability Zones.. Option B is correct because a Multi-AZ deployment with a standby instance provides automatic failover, but only supports two Availability Zones (primary and standby). For three AZs, Amazon Aurora is needed. Option A is wrong because Aurora with three replicas provides high availability across three AZs. Option C is wrong because Read Replicas are for read scaling, not automatic failover. Option D is wrong because a Single-AZ deployment is not highly available.

Answer

Deploy Amazon RDS for MySQL in a Single-AZ configuration and use an Application Load Balancer.

Answer

Deploy Amazon RDS for MySQL with Multi-AZ and a standby instance in a different Availability Zone.

Answer

Deploy Amazon RDS for MySQL with Read Replicas in two additional Availability Zones.

Question 10

A company is migrating a 100 GB Oracle database to Amazon RDS for Oracle. They want to use AWS DMS. The source database is in a different AWS account. What is required to allow DMS to connect to the source?

Accepted Answer

Establish VPC peering or VPN between the source and target VPCs, and configure security group rules.. Option C is correct because DMS needs network connectivity via VPC peering or VPN, and the source security group must allow DMS. Option A is wrong because VPC endpoints are not needed for DMS to source. Option B is wrong because DMS does not use an S3 endpoint for source connectivity. Option D is wrong because DMS does not use an IAM role for database connectivity; it uses database credentials.

Answer

Assign an IAM role to the source database to allow DMS access.

Answer

Configure an S3 VPC gateway endpoint for the source VPC.

Answer

Create a VPC endpoint for DMS in the source account.

Question 11

A company is planning to migrate a 3 TB PostgreSQL database from an on-premises data center to Amazon Aurora PostgreSQL. The migration must have near-zero downtime. The on-premises database is using a custom pg_hba.conf that restricts access to specific IP ranges. Which combination of steps will meet the requirements?

Accepted Answer

Use AWS DMS with ongoing replication to an Aurora DB cluster. Configure the source endpoint with the appropriate connection settings.. Using AWS DMS with ongoing replication from an on-premises source to Aurora is the standard approach for near-zero downtime migrations. The other options either require downtime or are not feasible (e.g., Aurora standby cluster cannot be created from on-premises).

Answer

Create an Aurora Replica of the on-premises database using cross-Region replication.

Answer

Use pg_dump and pg_restore to export and import the database during a maintenance window.

Answer

Use AWS SCT to convert the schema and then perform a full data load using AWS DMS.

Question 12

A database administrator runs the above CLI command. The output shows that 'mydb' is a read replica of 'mydb-source'. The administrator wants to promote 'mydb' to a standalone instance with no downtime. Which action should be taken?

Accepted Answer

Use the promote-read-replica CLI command.. Option C is correct because promoting a read replica makes it a standalone instance; it can be done without downtime. Option A is wrong because modifying MultiAZ requires a reboot, causing downtime. Option B is wrong because creating a snapshot and restoring is not a promotion. Option D is wrong because modifying the DB instance class requires a reboot.

Answer

Modify the DB instance to enable Multi-AZ, which automatically promotes it.

Answer

Create a snapshot of the read replica and restore it as a new DB instance.

Answer

Modify the DB instance class to a larger size to force promotion.

Question 13

A company is migrating a 2 TB PostgreSQL database from on-premises to Amazon RDS for PostgreSQL. The database has a 4-hour downtime window. The company requires minimal data loss and wants to use AWS DMS. The on-premises network has a 100 Mbps internet connection. Which migration method should the company use?

Accepted Answer

Use AWS DMS with a full load and ongoing change data capture (CDC) replication.. Option B is correct because AWS DMS with a full load and ongoing CDC allows minimal downtime by continuously replicating changes. Option A is wrong because AWS DMS full load only does not capture ongoing changes, leading to data loss. Option C is wrong because pg_dump/pg_restore does not support CDC. Option D is wrong because AWS SCT is a schema conversion tool, not a data migration tool.

Answer

Use AWS Schema Conversion Tool (SCT) to migrate the data to Amazon RDS.

Answer

Use AWS DMS with a full load only, then stop the source database and resume applications.

Answer

Use pg_dump and pg_restore to export and import the database during the downtime window.

Question 14

Which TWO methods can be used to encrypt an existing unencrypted Amazon RDS for Oracle DB instance? (Choose 2.)

Accepted Answer

Create a snapshot of the DB instance, copy the snapshot with encryption enabled, and restore the DB instance from the encrypted snapshot.. Options A and D are correct because you can create a snapshot, copy it with encryption, and restore; or use DMS to migrate to an encrypted target. Option B is wrong because you cannot directly enable encryption on an existing instance. Option C is wrong because enabling encryption on a replica requires the source to be encrypted. Option E is wrong because the console does not allow direct modification.

Answer

Use the AWS Management Console to toggle encryption on the DB instance.

Answer

Modify the DB instance and enable encryption in the configuration.

Answer

Create a read replica with encryption enabled.

Question 15

A company is using Amazon DynamoDB with global tables. The company wants to monitor replication latency between regions. Which CloudWatch metric should the company use?

Accepted Answer

ReplicationLatency. Option A is correct because ReplicationLatency is the metric for global tables. Option B is incorrect for this purpose. Option C is incorrect because it is a custom metric. Option D is incorrect because it is for RDS.

Answer

GlobalTableReplicationLag

Answer

ReplicaLag

Answer

WriteThrottleEvents