DBS-C01 Deployment and Migration Practice Test 3 — 15 Questions

Question 1

A company is migrating a 100 GB SQL Server database to Amazon RDS for SQL Server. They need to minimize downtime and ensure that only the schema is converted. Which tool should they use?

Accepted Answer

AWS Schema Conversion Tool (SCT). AWS Schema Conversion Tool (SCT) is the correct choice because it is specifically designed to convert database schemas (including stored procedures, functions, and data types) from one engine to another, such as SQL Server to Amazon RDS for SQL Server. Since the requirement is to minimize downtime and only convert the schema (not migrate data), SCT can perform an offline schema conversion without impacting the source database, whereas DMS is a continuous data replication tool that would incur downtime for schema changes.

Answer

AWS Database Migration Service (DMS)

Answer

AWS DMS with schema conversion enabled

Answer

SQL Server Management Studio (SSMS)

Question 2

A company is migrating a 500 GB Oracle database to Amazon Aurora PostgreSQL. They need to convert the schema and migrate the data with minimal downtime. Which THREE actions should they take? (Choose three.)

Accepted Answer

Use AWS Schema Conversion Tool (SCT) to assess and convert Oracle-specific features like hierarchical queries.. Option A is correct because AWS SCT performs an assessment report that identifies Oracle-specific constructs such as hierarchical queries (CONNECT BY), PL/SQL packages, and other features that cannot be automatically converted, which is essential before migrating to Aurora PostgreSQL. Option C is correct because AWS DMS with change data capture (CDC) performs a full load followed by ongoing replication of changes from the Oracle source, enabling minimal downtime during cutover. Option D is correct because AWS SCT converts the Oracle schema objects (tables, indexes, constraints, sequences, and views) into PostgreSQL-compatible DDL that Aurora PostgreSQL can run. Option B is not needed because the application should generally remain unchanged; the migration tools handle syntax conversion, and rewriting the app beforehand is not a required migration action. Option E is not appropriate because Snowball Edge is for offline bulk data transfer, which would not provide the minimal-downtime, continuously replicated migration that DMS with CDC delivers for a 500 GB database.

Answer

Modify the application to use Aurora PostgreSQL-specific SQL syntax before migration.

Answer

Use AWS Snowball Edge to transfer the data to AWS and then load into Aurora.

Question 3

A company is deploying a new application using Amazon RDS for PostgreSQL. They require high availability with automatic failover and the ability to offload read traffic. Which TWO features should they enable? (Choose two.)

Accepted Answer

Multi-AZ deployment. Option A, Multi-AZ deployment, is correct because it creates a synchronous standby replica in a different Availability Zone and provides automatic failover to that standby if the primary instance fails, satisfying the high availability requirement. Option B, Read replicas, is correct because RDS for PostgreSQL read replicas use asynchronous replication to serve read-only traffic, allowing the company to offload read queries from the primary instance. Option C, Performance Insights, is incorrect because it is only a monitoring and diagnostics tool and does not provide failover or read offloading. Option D, Global Database, is incorrect because it is designed for cross-Region disaster recovery and low-latency global reads, not the standard in-Region high availability and read offloading described here. Option E, Auto Scaling for read replicas, is incorrect because it automatically adjusts the number of read replicas based on load but does not itself provide automatic failover for the primary database.

Answer

Performance Insights

Answer

Global Database

Answer

Auto Scaling for read replicas

Question 4

A company is migrating a 2 TB Oracle database to Amazon Aurora PostgreSQL. The migration must have minimal downtime and support ongoing replication. Which AWS service should be used?

Accepted Answer

AWS Database Migration Service (AWS DMS). AWS Database Migration Service (AWS DMS) is the correct choice because it supports ongoing replication (change data capture, CDC) from an Oracle source to an Amazon Aurora PostgreSQL target, enabling a migration with minimal downtime. DMS can handle a 2 TB database by using a large replication instance and tuning task settings, and it continuously replicates changes until the cutover is complete.

Answer

AWS DataSync

Answer

Amazon S3 Glacier

Answer

AWS Schema Conversion Tool (AWS SCT)

Question 5

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.. AWS DMS performs a full load directly from the source Oracle database to the target RDS for Oracle instance over the network, leveraging the 1 Gbps bandwidth efficiently. For a 500 GB database, a full load at 1 Gbps (theoretical max ~450 Gbps per hour) can complete in under 2 hours, well within the 4-hour window, without requiring intermediate storage or schema conversion.

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 6

A company is migrating a 3 TB SQL Server database to Amazon RDS for SQL Server. The migration must be completed with less than 15 minutes of downtime. The company has set up AWS DMS with ongoing replication. During the final cutover, the DMS task fails with a 'Target error: Cannot insert duplicate key' error. What is the most likely cause?

Accepted Answer

The target table has an identity column that is not set to allow insert of explicit values.. The error 'Cannot insert duplicate key' during DMS full load or ongoing replication indicates that the target table has an identity column that does not allow explicit value insertion. By default, SQL Server identity columns are set to NOT FOR REPLICATION = OFF, meaning DMS cannot insert rows with explicit identity values, causing duplicate key violations when the source has identity values that conflict with the target's auto-generated sequence. To resolve this, you must set the identity column to allow explicit inserts (e.g., SET IDENTITY_INSERT ON) or configure DMS to use 'Do nothing' for identity handling.

Answer

The DMS task is not set to truncate the target before loading.

Answer

The source database transaction log is full.

Answer

The source database has a primary key violation.

Question 7

A company is migrating an on-premises PostgreSQL database to Amazon RDS for PostgreSQL. The migration must have minimal downtime. Which TWO AWS services should be used together to achieve this?

Accepted Answer

AWS Database Migration Service (AWS DMS). AWS DMS (option C) is correct because it performs continuous data replication from the on-premises PostgreSQL source to Amazon RDS for PostgreSQL, using change data capture (CDC) to keep the target in sync and enable a cutover with minimal downtime. AWS SCT (option E) is correct because it assesses and converts the source database schema and objects (tables, views, stored procedures, etc.) into a format compatible with the RDS PostgreSQL target, which is a required step before or alongside DMS replication. AWS DataSync (option A) is for file/object data transfer, not database replication, so it cannot keep a live PostgreSQL database synchronized. CloudEndure Migration (option B) is for lift-and-shift server replication (now part of AWS Application Migration Service), not for database-level migration to RDS. AWS Direct Connect (option D) only provides a dedicated network connection and does not itself perform schema conversion or database replication.

Answer

AWS DataSync

Answer

AWS CloudEndure Migration

Answer

AWS Direct Connect

Question 8

A company is migrating a 2 TB Oracle database to Amazon Aurora PostgreSQL. The migration requires ongoing replication for minimal downtime. Which THREE AWS services should be used?

Accepted Answer

AWS Database Migration Service (AWS DMS). AWS DMS (A) is correct because it performs the actual data migration and supports ongoing (change data capture) replication from Oracle to Aurora PostgreSQL, enabling minimal-downtime cutover. AWS SCT (D) is correct because Oracle-to-Aurora PostgreSQL is a heterogeneous migration, so the schema, stored procedures, and other database objects must be converted to PostgreSQL-compatible DDL before or alongside the DMS task. Amazon S3 (B) is correct because DMS uses an S3 bucket as intermediate storage for the full load and for the change data capture (CDC) files that replicate ongoing changes to the target. AWS DataSync (C) is not appropriate because it is a file/object transfer service for moving data between on-premises storage and AWS storage services, not for database replication. AWS Lambda (E) is not required because it is an event-driven compute service and does not perform database schema conversion or ongoing database replication.

Answer

AWS DataSync

Answer

AWS Lambda

Question 9

A company is deploying a multi-AZ Aurora MySQL database. They need to ensure that failover happens automatically with minimal data loss. Which configuration should be used?

Accepted Answer

Create an Aurora cluster with one primary and two readers in different Availability Zones.. An Aurora cluster with one primary and two readers in different Availability Zones provides automatic failover with minimal data loss. Aurora uses a shared cluster volume that is replicated six ways across three AZs, ensuring that during a failover, the promoted reader has access to all committed transactions with no data loss. This configuration meets the requirement for multi-AZ high availability and automatic failover within a single region.

Answer

Deploy an Aurora Global Database with a primary in one region and a secondary in another region.

Answer

Use a Multi-AZ RDS for MySQL deployment.

Answer

Configure a single-AZ Aurora instance and enable cross-Region replication.

Question 10

A company is migrating a 10 TB PostgreSQL database from on-premises to Amazon RDS for PostgreSQL. They need to minimize downtime and have limited network bandwidth. Which approach is most appropriate?

Accepted Answer

Use AWS Snowball to transfer a physical backup to AWS, then use DMS for ongoing replication.. The 10 TB database size combined with limited network bandwidth makes a direct online migration impractical due to prolonged transfer times. AWS Snowball allows you to physically ship the database backup to AWS, bypassing bandwidth constraints. After loading the backup into Amazon RDS, AWS DMS can perform ongoing change data capture (CDC) replication to synchronize any changes made during the transfer, minimizing downtime.

Answer

Use AWS Database Migration Service (DMS) with a full load and ongoing replication to keep the target in sync.

Answer

Use pg_dump to export the database and pg_restore to import to RDS, then use DMS for replication.

Answer

Use AWS Direct Connect to increase bandwidth and then use DMS for full load and replication.

Question 11

A company is migrating a 5 TB MongoDB database to Amazon DocumentDB. They have a short maintenance window and need to minimize downtime. Which migration strategy should be used?

Accepted Answer

Use AWS DMS to perform a full load and then ongoing replication from the source MongoDB.. AWS DMS supports MongoDB as a source and Amazon DocumentDB as a target, enabling a full load of the 5 TB database followed by ongoing change data capture (CDC) using MongoDB's oplog. This minimizes downtime by keeping the target nearly synchronized during the migration window, allowing a final cutover with minimal interruption.

Answer

Use the MongoDB change streams feature to replicate changes to DocumentDB in real time.

Answer

Set up AWS Direct Connect to the source and use mongorestore directly to DocumentDB.

Answer

Export the data using mongodump, transfer to Amazon S3, and import using mongorestore.

Question 12

A company is deploying a new application that requires a globally distributed database with low latency reads. They choose Amazon DynamoDB global tables. What is a key consideration for this deployment?

Accepted Answer

Each replica can serve reads and writes independently.. Amazon DynamoDB global tables use a multi-master, active-active replication model. This means each replica region can independently serve both reads and writes, with eventual consistency across regions. This design enables low-latency local reads and writes for globally distributed applications, as each region operates autonomously.

Answer

Writes are synchronously replicated to all regions.

Answer

The table class must be DynamoDB Standard-Infrequent Access.

Answer

Global tables support strongly consistent reads from any region.

Question 13

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.. Option A is correct because AWS Database Migration Service (DMS) can perform a full load of the 2 TB database and then continue with ongoing change data capture (CDC) replication from the source SQL Server to Amazon RDS for SQL Server, keeping the target synchronized so the final cutover requires only a brief downtime. Option C is correct because the AWS Schema Conversion Tool (SCT) assesses source-to-target compatibility and converts schema objects, stored procedures, and other code that may not transfer cleanly to RDS for SQL Server, which is essential for a smooth, low-downtime migration. Together, SCT handles schema conversion and DMS handles data migration plus continuous replication, directly addressing the limited maintenance window. Option B is not required because Direct Connect increases network bandwidth but does not by itself minimize migration downtime or handle schema/data replication. Option D is incorrect because CloudEndure Migration targets server (EC2) rehosting, not database-level migration to RDS. Option E is incorrect because AWS Snowball is an offline bulk-transfer device and would not support ongoing replication or a short cutover window for a live database.

Answer

Use AWS Direct Connect to increase bandwidth.

Answer

Use AWS CloudEndure Migration.

Answer

Use AWS Snowball to transfer a backup offline.

Question 14

Refer to the exhibit. An IAM policy is attached to a user. The user attempts to create an RDS DB instance named 'new-prod-db' with Oracle Standard Edition Two engine. What will happen?

Accepted Answer

The request will fail because the Deny condition matches the engine.. The IAM policy includes an explicit Deny for the `rds:CreateDBInstance` action when the engine is `oracle-se2`, which matches the Oracle Standard Edition Two engine. Since explicit Deny statements override any Allow statements, the request fails regardless of the name pattern match. AWS IAM evaluates Deny statements first, making the Deny effective and blocking the operation.

Answer

The request will fail because there is no Allow for 'new-prod-db'.

Answer

The request will succeed because the Allow matches the name pattern.

Answer

The request will succeed because the Deny is not effective for 'new-prod-db'.

Question 15

A company is migrating a 2 TB on-premises PostgreSQL database to Amazon RDS for PostgreSQL. The migration must have minimal downtime and support ongoing replication. Which AWS service should be used?

Accepted Answer

AWS DMS. AWS DMS (Database Migration Service) is the correct choice because it supports both full-load migration and ongoing change data capture (CDC) replication from an on-premises PostgreSQL source to Amazon RDS for PostgreSQL, enabling minimal downtime. DMS uses logical replication slots to capture incremental changes, allowing the target database to stay synchronized during the cutover window.

Answer

AWS Snowball Edge

Answer

AWS S3

Answer

RDS native PostgreSQL logical replication