DBS-C01 Deployment and Migration Practice Test 18 — 15 Questions

Question 1

A company is migrating a 1 TB SQL Server database to Amazon RDS for SQL Server. They need to minimize downtime and support ongoing replication. Which combination of AWS services should they use?

Accepted Answer

AWS SCT and AWS DMS. AWS DMS (Database Migration Service) can perform a full load of the 1 TB SQL Server database and then continuously replicate ongoing changes using change data capture (CDC) to minimize downtime. AWS SCT (Schema Conversion Tool) is used to assess and convert any incompatible schema objects (e.g., stored procedures, indexes) from the source SQL Server to the target RDS for SQL Server, ensuring a smooth migration. Together, they provide a complete solution for heterogeneous or homogeneous migration with minimal downtime and ongoing replication.

Answer

AWS S3 and AWS Glue

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AWS DMS alone

Answer

Native SQL Server backup and restore to RDS

Question 2

A media company is migrating a 5 TB MongoDB database to Amazon DocumentDB. The migration must have minimal downtime. The source MongoDB uses sharding across 10 shards. Which migration strategy is MOST appropriate?

Accepted Answer

Use AWS DMS with MongoDB as source and DocumentDB as target, enabling CDC. AWS DMS with CDC (Change Data Capture) is the most appropriate strategy because it supports ongoing replication from a sharded MongoDB source to Amazon DocumentDB, enabling near-zero downtime migration. DMS can handle the 5 TB dataset and 10 shards by using the MongoDB oplog to capture changes after the initial full load, ensuring minimal interruption to the media company's operations.

Answer

Use native MongoDB replication to sync to DocumentDB

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Export data to S3 and use AWS Glue to load into DocumentDB

Answer

Use mongoexport to export data and mongoimport to import into DocumentDB

Question 3

A company is migrating an on-premises MySQL database to Amazon RDS for MySQL. The database has a table with 100 million rows. During the migration using AWS DMS, the full load phase is taking too long. What change can speed up the full load?

Accepted Answer

Increase the number of DMS task mappings (parallel threads). Increasing the number of DMS task mappings (parallel threads) allows DMS to partition the source table and load multiple segments concurrently, significantly reducing the full load duration. By default, DMS uses a single thread per table; adding parallel threads leverages the source database's read capacity and the target RDS instance's write throughput more efficiently.

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Reduce the target RDS instance storage to minimize write latency

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Increase the size of the source on-premises database instance

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Disable LOB columns in the task settings

Question 4

A company is migrating a 2 TB Oracle database to Amazon Aurora PostgreSQL using AWS SCT and DMS. After migration, the application reports that some queries are significantly slower than before. The database schema was converted automatically. What is the most likely cause?

Accepted Answer

The schema conversion did not create appropriate indexes. The most likely cause is that AWS Schema Conversion Tool (SCT) converted the Oracle schema to Aurora PostgreSQL but did not automatically create optimal indexes. Oracle and PostgreSQL use different query optimizers and index strategies; SCT focuses on structural compatibility, not performance tuning. Without manual review and addition of appropriate indexes (e.g., for foreign keys, composite columns, or partial indexes), PostgreSQL may resort to sequential scans on large tables, causing significant query slowdowns.

Answer

Aurora storage is slower than Oracle's storage

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DMS introduced data type conversions that slow down queries

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Aurora PostgreSQL does not support partitioning, causing full table scans

Question 5

A company is migrating a 500 GB database from Amazon RDS for MySQL to Amazon Aurora MySQL. The migration must be completed with minimal downtime and no data loss. The RDS instance is Multi-AZ. Which approach should be used?

Accepted Answer

Create an Aurora MySQL read replica from the RDS MySQL instance, then promote it. Creating an Aurora MySQL read replica from the RDS MySQL instance uses the native MySQL binary log (binlog) replication to keep the Aurora cluster synchronized with minimal downtime. Once the replica lag reaches zero, you promote the Aurora cluster to make it the primary database, ensuring no data loss and a very short cutover window.

Answer

Use AWS DMS with ongoing replication from RDS to Aurora

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Take a snapshot of the RDS instance and restore to Aurora

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Set up native MySQL replication from the RDS Multi-AZ standby to Aurora

Question 6

A company is migrating an on-premises Oracle database to Amazon RDS for Oracle. They need to minimize downtime. Which TWO actions should they take?

Accepted Answer

Set up AWS DMS with change data capture (CDC) from the source. AWS DMS with change data capture (CDC) enables continuous replication of ongoing changes from the source Oracle database to the target RDS instance. This allows the source to remain fully operational during the bulk load phase and then switch over with minimal downtime, as only the final CDC catch-up is needed before cutover.

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Increase the allocated storage on the target RDS instance to improve performance

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Deploy the target RDS instance as a Single-AZ to simplify replication

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Disable Oracle archivelog mode to speed up data transfer

Question 7

A company is migrating a 3 TB PostgreSQL database to Amazon Aurora PostgreSQL. The migration must have minimal downtime. Which THREE steps should be taken?

Accepted Answer

Use AWS DMS with ongoing replication from the source PostgreSQL database. AWS DMS with ongoing replication (change data capture, CDC) allows continuous synchronization from the source PostgreSQL database to the target Aurora PostgreSQL cluster, enabling a cutover with minimal downtime. This is the standard approach for live migrations where the source remains fully operational during the transfer.

Answer

Disable autovacuum on the Aurora cluster to improve migration performance

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Use AWS Snowball Edge to transfer the data offline

Question 8

A company is planning to migrate a 1 TB SQL Server database to Amazon RDS for SQL Server. Which TWO factors should be considered when choosing the migration approach?

Accepted Answer

The need to modify the database schema for compatibility. When migrating a SQL Server database to Amazon RDS, certain features like full-text search, CLR assemblies, or deprecated data types may not be supported or require schema modifications. RDS for SQL Server does not support all SQL Server features (e.g., FileStream, Service Broker, or cross-database references), so the schema must be reviewed and potentially altered to ensure compatibility before migration.

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The number of concurrent users accessing the database

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Whether the database uses SQL Server Agent jobs

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The version of the source SQL Server instance

Question 9

A company is migrating an on-premises PostgreSQL database to Amazon RDS for PostgreSQL. The database is 2 TB and has a sustained write rate of 150 MB/s. The migration must have minimal downtime. Which AWS service or tool should be used for the initial data load and ongoing replication?

Accepted Answer

Use AWS Database Migration Service (AWS DMS) with full load and ongoing replication. AWS DMS is the correct choice because it supports both a full load of the existing 2 TB database and ongoing change data capture (CDC) to replicate transactions with minimal downtime. DMS can handle sustained write rates of 150 MB/s by using appropriate instance sizing and tuning, and it provides built-in mechanisms for resumable loads and validation, which are critical for a large-scale migration with minimal downtime.

Answer

Use pg_dump and pg_restore

Answer

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

Answer

Use AWS S3 Transfer Acceleration to upload data to Amazon S3, then restore to RDS

Question 10

A company is deploying a new multi-AZ application that requires a relational database. The database must be highly available and must automatically failover to a standby in another Availability Zone within minutes. The database size is 500 GB and the workload is read-heavy. Which AWS RDS configuration meets these requirements?

Accepted Answer

Deploy Amazon RDS for MySQL with Multi-AZ and a read replica in a different AZ. Deploying Amazon RDS for MySQL with Multi-AZ provides automatic failover to a standby in a different Availability Zone within minutes, meeting the high availability requirement. Adding a read replica in a different AZ offloads read traffic, which is ideal for the read-heavy workload, without affecting the primary database's performance.

Answer

Deploy Amazon Aurora with Multi-AZ

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Deploy Amazon RDS for PostgreSQL with a cross-Region read replica

Answer

Deploy Amazon RDS for Oracle with RDS Proxy

Question 11

A developer is deploying an application that uses Amazon DynamoDB as its database. The application experiences sudden spikes in traffic. Which DynamoDB feature should the developer use to handle the spikes without manual intervention?

Accepted Answer

DynamoDB auto scaling. DynamoDB auto scaling (option C) is the correct choice because it automatically adjusts the provisioned read and write capacity based on actual traffic patterns using the AWS Application Auto Scaling service. This allows the application to handle sudden spikes in traffic without manual intervention by increasing capacity when utilization rises and decreasing it when traffic subsides, all while maintaining a target utilization percentage.

Answer

DynamoDB Accelerator (DAX)

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DynamoDB on-demand capacity mode

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DynamoDB global tables

Question 12

A company is migrating an on-premises Oracle database to Amazon RDS for Oracle. The database is 1 TB and has a large number of stored procedures and triggers. The migration must minimize application changes. Which migration approach should be used?

Accepted Answer

Use AWS Database Migration Service (AWS DMS) with full load and ongoing replication. AWS DMS with full load and ongoing replication minimizes application changes by supporting heterogeneous migrations with minimal downtime, and it can handle stored procedures and triggers by replicating data changes in near real-time without requiring schema conversion. AWS DMS directly supports Oracle as a source and Amazon RDS for Oracle as a target, preserving the existing schema and procedural logic, which avoids the need for application rewrites.

Answer

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

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Use Oracle Data Pump (expdp/impdp) to export and import the database

Answer

Use AWS S3 to store the data and AWS Glue to transform and load into RDS

Question 13

A company is deploying a new web application on AWS. The application uses Amazon RDS for MySQL with a Multi-AZ deployment. The application team wants to reduce latency for read-heavy workloads. Which action should be taken?

Accepted Answer

Add a read replica in the same Region. Adding a read replica in the same Region offloads read-heavy workloads from the primary RDS instance, reducing latency for read queries because replicas serve read traffic directly. Amazon RDS for MySQL read replicas use asynchronous replication and can be promoted to a primary instance if needed, making this the most effective and cost-efficient solution for read scaling.

Answer

Enable Multi-AZ on the existing RDS instance

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Increase the instance size of the primary RDS instance

Answer

Switch from RDS to Amazon DynamoDB with DAX

Question 14

A company is deploying a new application that requires a relational database with automatic failover and cross-Region disaster recovery. The application is read-heavy and expects up to 10 GB of data. Which combination of AWS services should be used?

Accepted Answer

Amazon Aurora with Multi-AZ and an Aurora global database. Amazon Aurora with Multi-AZ provides high availability within a single Region, while Aurora Global Database enables cross-Region disaster recovery with typical replication latency of under one second. Aurora is optimized for read-heavy workloads and scales automatically, making it ideal for the 10 GB dataset and the application's requirements.

Answer

Amazon RDS for MySQL with Multi-AZ and a read replica in another Region

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Amazon S3 with AWS Glue and Amazon Athena

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Amazon DynamoDB with global tables

Question 15

A company is migrating a 500 GB SQL Server database to Amazon RDS for SQL Server. The database has a large number of stored procedures and triggers. The migration must have minimal downtime. Which approach should be used?

Accepted Answer

Use AWS Database Migration Service (AWS DMS) with full load and ongoing replication. AWS DMS with full load and ongoing replication enables continuous change data capture (CDC) from the source SQL Server database to Amazon RDS for SQL Server, minimizing downtime by keeping the target synchronized until cutover. This approach handles the stored procedures and triggers natively since both source and target are SQL Server, avoiding schema conversion issues.

Answer

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

Answer

Use AWS S3 to store the data and AWS Glue to transform and load into RDS

Answer

Use native SQL Server backup and restore to Amazon RDS