DBS-C01 Practice Test 31 — 15 Questions

Question 1

A company is migrating a 500 GB Oracle database to Amazon RDS for Oracle. The migration must complete within a 4-hour downtime window. The network bandwidth is 1 Gbps. Which migration approach minimizes the migration time?

Accepted Answer

Use AWS DMS to perform a full load of the database to RDS.. Option D is correct because AWS DMS can perform a full load plus ongoing replication, but given the bandwidth and data size, using a direct connection (DX) or SCT is not faster. However, the best approach is to use DMS with full load only if replication is not needed; DMS can load data faster than native export/import. Option A is wrong because native export/import is slower and more manual. Option B is wrong because SCT is for schema conversion only. Option C is wrong because DataSync is for files, not databases.

Answer

Use AWS Schema Conversion Tool (SCT) to convert the schema, then use AWS DMS for data migration.

Answer

Use Oracle Data Pump to export and import the database.

Answer

Use AWS DataSync to copy the database files to Amazon S3, then restore to RDS.

Question 2

A developer is connecting to an RDS for MySQL instance. What is the endpoint address that should be used in the database connection string?

Accepted Answer

mydb.123456789012.us-east-1.rds.amazonaws.com. Option B is correct because the endpoint address is the DNS name shown in the output. Option A is wrong because the instance ID is not the endpoint. Option C is wrong because the port is not the address. Option D is wrong because the HostedZoneId is not used as the endpoint.

Answer

mydb

Answer

3306

Answer

Z1R2S3V4X5Y6Z7

Question 3

A company is migrating an on-premises MySQL database to Amazon RDS for MySQL. Which TWO AWS services can assist in assessing the source database for compatibility issues?

Accepted Answer

AWS Database Migration Service (DMS). AWS SCT can assess source schema for compatibility with RDS. AWS DMS can assess data types and conversion issues as part of its task validation. Trusted Advisor is for cost optimization, not database compatibility. CloudWatch is for monitoring. Inspector is for security assessment.

Answer

AWS Trusted Advisor

Answer

Amazon CloudWatch

Answer

Amazon Inspector

Question 4

A company uses a self-hosted MySQL database on EC2. They want to migrate to Amazon RDS for MySQL with minimal downtime and automated failover. Which migration strategy should be used?

Accepted Answer

Set up MySQL replication from EC2 to RDS, then cut over. Option D is correct because setting up replication from EC2 to RDS using MySQL native replication allows near-zero downtime cutover. Option A is wrong because dump/restore requires downtime. Option B is wrong because snapshot restore requires downtime. Option C is wrong because DMS might add complexity and is not necessary if native replication works.

Answer

Use mysqldump to export the database and import to RDS

Answer

Take a snapshot of the EC2 instance and restore to RDS

Answer

Use AWS DMS with full load and CDC

Question 5

Refer to the exhibit. A DBA is monitoring a DMS migration task from on-premises Oracle to Amazon RDS for Oracle. The full load completed successfully with 50 tables. However, the DBA notices that the CDC phase has not started. What is the most likely reason?

Accepted Answer

The replication task was stopped after the full load completed. Option B is correct because if the task is stopped after full load, CDC will not start. The stop date is 1 hour after start, indicating the task stopped. Option A is wrong because tables loaded shows 50, not errored. Option C is wrong because DMS does not require manual CDC enable. Option D is wrong because the task might be stopped, not pending.

Answer

The task was not configured with CDC enabled

Answer

The full load encountered errors on some tables

Answer

The source Oracle database is not generating redo logs

Question 6

A company is migrating an on-premises PostgreSQL database to Amazon RDS for PostgreSQL. Which TWO AWS services can be used to assess the source database for compatibility and migration readiness?

Accepted Answer

AWS Schema Conversion Tool (SCT). AWS DMS can assess source database compatibility and perform data migration. AWS SCT can assess schema compatibility and convert the schema. Option C (CloudWatch) is for monitoring. Option D (Kinesis) is for streaming. Option E (Glue) is for ETL.

Answer

Amazon Kinesis

Answer

AWS Glue

Answer

Amazon CloudWatch

Question 7

A company is migrating a 10 TB Oracle Data Warehouse to Amazon Redshift. The source database runs on premises with limited bandwidth (100 Mbps). The migration must complete within 5 days. Which approach is most cost-effective and meets the timeline?

Accepted Answer

Use AWS Snowball Edge to transfer the initial full load, then AWS DMS for ongoing changes.. Option C is correct because AWS Snowball Edge can transfer 10 TB in days, then use DMS for ongoing sync. Option A is wrong because 100 Mbps would take ~11 days for full load alone. Option B is wrong because direct DMS over 100 Mbps would take too long for initial load. Option D is wrong because SCT is not a data transfer tool.

Answer

Use AWS DMS over the internet to migrate data.

Answer

Use AWS Schema Conversion Tool (SCT) to convert and then upload to S3.

Answer

Use AWS DMS with AWS Direct Connect at 1 Gbps.

Question 8

An administrator needs to migrate an on-premises MongoDB database to Amazon DocumentDB. The migration must have near-zero downtime. Which approach should the administrator use?

Accepted Answer

Use AWS DMS with MongoDB as source and DocumentDB as target. Option B is correct because AWS DMS supports ongoing replication from MongoDB to DocumentDB using change streams. Option A is wrong because mongodump/mongorestore is a one-time import with downtime. Option C is wrong because AWS DataSync is for file-based transfers, not databases. Option D is wrong because AWS Glue is for ETL, not live replication.

Answer

Use AWS DataSync to transfer the MongoDB data files

Answer

Use AWS Glue to extract and load data

Answer

Use mongodump to export and mongorestore to import

Question 9

A company is migrating an on-premises Oracle database to Amazon RDS for Oracle. The database uses Oracle Data Pump for export/import. The migration must be completed within a short maintenance window. Which migration approach should they use?

Accepted Answer

Use AWS Database Migration Service with full load and change data capture (CDC).. Option A (Use AWS DMS with a full load + CDC) is correct because it minimizes downtime by capturing changes. Option B (Use Oracle Data Pump export/import) requires significant downtime. Option C (Use AWS SCT to convert schema and then use DMS) is unnecessary if staying on Oracle. Option D (Use AWS Snowball) is for large data transfers, not for minimal downtime.

Answer

Use AWS Snowball to transfer the database files to AWS and then restore to RDS.

Answer

Use Oracle Data Pump to export the database and import into RDS.

Answer

Use AWS Schema Conversion Tool (SCT) to convert the schema and then use DMS for data migration.

Question 10

A company is deploying Amazon RDS for PostgreSQL and needs to ensure that all data at rest is encrypted. Which action should be taken to enable encryption?

Accepted Answer

Specify an AWS KMS key when creating the RDS instance.. Option B is correct because RDS encryption at rest is enabled at instance creation time using AWS KMS. Option A is wrong because encryption is not enabled by default. Option C is wrong because encryption cannot be enabled on an existing unencrypted instance without a snapshot restore. Option D is wrong because you must specify a KMS key.

Answer

Modify the existing RDS instance to enable encryption.

Answer

Enable encryption by default in the RDS console.

Answer

Enable encryption using S3 server-side encryption.

Question 11

A company wants to migrate an on-premises Oracle database to Amazon RDS for Oracle with minimal downtime. Which AWS service should be used for the initial data load and ongoing replication?

Accepted Answer

AWS Database Migration Service (DMS). AWS DMS can perform a full load and then continuously replicate changes to keep the target in sync with the source, enabling minimal downtime migration. SCT is used for schema conversion, not replication. Direct Connect provides network connectivity, not data migration. Snowball is for offline data transfer and does not support ongoing replication.

Answer

AWS Snowball

Answer

AWS Direct Connect

Answer

AWS Schema Conversion Tool (SCT)

Question 12

A company is migrating a 2 TB SQL Server database to Amazon RDS for SQL Server. They have a limited maintenance window and need to minimize downtime. Which TWO strategies should they combine?

Accepted Answer

Use AWS DMS to perform a full load and ongoing replication.. Using DMS for full load and ongoing replication minimizes downtime. AWS SCT is needed to convert schema if there are incompatibilities. Snowball is for offline transfer, but with 2 TB and limited time, DMS online is better. Direct Connect improves network but is not a migration strategy. CloudEndure is for server migration.

Answer

Use AWS Direct Connect to increase bandwidth.

Answer

Use AWS CloudEndure Migration.

Answer

Use AWS Snowball to transfer a backup offline.

Question 13

A company is migrating a 10 TB Oracle database to Amazon Aurora PostgreSQL. The migration uses AWS DMS with CDC. After the full load, the CDC phase is falling behind by several minutes. The source Oracle database generates 500 MB of redo logs per minute. Which action will most likely improve CDC performance?

Accepted Answer

Increase the number of parallel apply threads on the DMS task. Option C is correct because increasing the DMS task's parallel apply threads can speed up the apply phase. Option A is wrong because increasing source redo log size does not affect DMS performance. Option B is wrong because disabling CDC is not a solution. Option D is wrong because reducing batch size would slow down processing.

Answer

Disable CDC and perform a full load only

Answer

Reduce the batch size in the DMS task settings

Answer

Increase the source Oracle redo log size

Question 14

A company is migrating an on-premises Oracle database to Amazon RDS for Oracle. The database is 5 TB in size and has a daily change rate of 2%. The migration must have minimal downtime. Which migration strategy should be used?

Accepted Answer

Use AWS Database Migration Service (DMS) with ongoing replication from the source database.. AWS DMS with ongoing replication allows continuous data sync with minimal downtime. Option A (AWS SCT + DMS) is not ideal because SCT is for schema conversion, not needed here. Option C (export/import) causes downtime. Option D (RDS read replica) is for within AWS, not on-premises to RDS.

Answer

Use AWS Schema Conversion Tool (SCT) to convert the schema, then use AWS DMS for full load only.

Answer

Create an RDS read replica in the same region and promote it.

Answer

Export the database to a dump file using Oracle Data Pump, upload to S3, and restore to RDS.

Question 15

A company is deploying a new Amazon RDS for Oracle database in a VPC. The database must be accessed by an application running on an EC2 instance in a different subnet. Which THREE steps are required to allow this access?

Accepted Answer

Configure the network ACL for the RDS subnet to allow inbound traffic from the EC2 subnet.. The security group of the RDS instance must allow inbound traffic from the EC2 security group. The VPC must have an association between subnets. The network ACLs must allow inbound traffic. Option D (Internet Gateway) is not needed for private connectivity. Option E (VPC peering) is not needed if in same VPC.

Answer

Create a VPC peering connection between the subnets.

Answer

Attach an Internet Gateway to the VPC.