DBS-C01 Deployment and Migration Practice Test 5 — 15 Questions

Question 1

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

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

AWS Database Migration Service (AWS DMS). AWS DMS is the correct choice because it supports homogeneous migrations (Oracle to Oracle) with minimal downtime through ongoing replication using change data capture (CDC). It can handle a 2 TB database by using a large enough replication instance and enabling task logging for validation, ensuring data consistency during the migration.

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AWS Schema Conversion Tool (AWS SCT)

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AWS DataSync

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AWS Glue

Question 2

A company is migrating a MySQL database from on-premises to Amazon RDS for MySQL. They want to use native MySQL replication to minimize downtime. Which configuration is required in the on-premises MySQL server?

Accepted Answer

Enable binary logging with binlog_format = ROW. Native MySQL replication requires binary logging on the source server to capture all changes. Setting binlog_format = ROW ensures that row-level changes are logged, which is the recommended format for cross-version replication and is required by Amazon RDS for MySQL to support replication from an external source. Without binary logging enabled, the on-premises MySQL server cannot act as a replication master.

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Enable the slow query log

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Enable the audit log

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Enable the error log

Question 3

A team is deploying a new Amazon Aurora MySQL database and needs to load 5 TB of data from an existing Amazon RDS for MySQL database with minimal downtime. The data is stored in InnoDB tables. Which approach is MOST efficient?

Accepted Answer

Create an Aurora read replica from the RDS for MySQL instance using binlog replication. Creating an Aurora read replica from an RDS for MySQL instance using binlog replication allows the Aurora cluster to synchronize with the source database in near real-time. Once the replica lag reaches zero, you can promote the Aurora cluster to become the primary database, achieving minimal downtime. This approach leverages the native MySQL binlog replication, which is efficient for large datasets like 5 TB and avoids the overhead of exporting or snapshotting the entire database.

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Take a snapshot of the RDS for MySQL instance and restore to Aurora

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Use AWS DMS with full load and ongoing replication

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Use mysqldump to export the database and import into Aurora

Question 4

A company is migrating a 500 GB SQL Server database to Amazon RDS for SQL Server. They need to minimize downtime and support ongoing changes during migration. Which approach should they take?

Accepted Answer

Use AWS DMS with full load and change data capture (CDC). AWS DMS with full load and change data capture (CDC) is the correct approach because it allows the initial 500 GB data load to be migrated while continuously replicating ongoing changes from the source SQL Server database to Amazon RDS for SQL Server. This minimizes downtime by enabling a cutover only after the target is fully synchronized, and it supports ongoing changes during migration without requiring the source database to be taken offline.

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Use native SQL Server backup and restore to RDS

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Set up a Direct Connect connection and use log shipping

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Use SQL Server Integration Services (SSIS) to replicate data

Question 5

A company is migrating an on-premises MongoDB database to Amazon DocumentDB. They need to ensure that the migration is completed with minimal downtime and that data remains consistent. Which tool should they use?

Accepted Answer

Use AWS DMS with MongoDB as source and DocumentDB as target. AWS DMS supports continuous change data capture (CDC) from MongoDB to Amazon DocumentDB, enabling near-zero downtime migration by replicating ongoing changes after the initial full load. This ensures data consistency without requiring application downtime, unlike batch export/import methods.

Answer

Use mongoexport and mongoimport

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Export data to Amazon S3 and load into DocumentDB

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Use MongoDB Atlas Live Migration

Question 6

A company is deploying a new Amazon DynamoDB table with global tables for a multi-region application. The application requires strongly consistent reads in the primary region and eventual consistency in secondary regions. Which write strategy should they use?

Accepted Answer

Use DynamoDB global tables with last writer wins (LWW) conflict resolution. DynamoDB global tables use last writer wins (LWW) conflict resolution based on the timestamp in the update, which automatically handles concurrent writes across regions. This strategy satisfies the requirement for strongly consistent reads in the primary region and eventual consistency in secondary regions, as global tables replicate data asynchronously and LWW ensures convergence without additional application logic.

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Use conditional writes to ensure consistency

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Use DynamoDB Streams to replicate writes to secondary regions

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Use DynamoDB transactions across regions

Question 7

A company wants to deploy an Amazon RDS for MySQL database for a new application. The database must be highly available with automatic failover. Which configuration should they choose?

Accepted Answer

Deploy a Multi-AZ instance with a standby replica. A Multi-AZ deployment for Amazon RDS automatically provisions and maintains a synchronous standby replica in a different Availability Zone. In the event of a failure, Amazon RDS automatically fails over to the standby, providing high availability without manual intervention. This configuration meets the requirement for automatic failover and high availability.

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Deploy a single-AZ instance with automated backups

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Deploy a cross-region replica

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Deploy a single-AZ instance with a read replica

Question 8

A company is migrating a 3 TB PostgreSQL database from on-premises to Amazon Aurora PostgreSQL. They need to minimize downtime and ensure that the migration is completed within a maintenance window. Which approach should they use?

Accepted Answer

Use AWS DMS with full load and ongoing replication (CDC). AWS DMS with full load and ongoing replication (CDC) is the correct approach because it allows you to perform an initial full load of the 3 TB database while continuously capturing changes from the source PostgreSQL using logical replication (via the pglogical extension or native slot-based replication). This minimizes downtime by keeping the target Aurora PostgreSQL nearly synchronized, and you can switch over during a maintenance window with only a brief outage to apply any final lag.

Answer

Use AWS SCT to convert the schema and then migrate data

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

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Take a file system snapshot and restore to Aurora

Question 9

A company is migrating an on-premises Oracle database to Amazon RDS for Oracle. The migration uses AWS DMS with ongoing replication (CDC). Which TWO tasks must be completed before starting the migration?

Accepted Answer

Enable supplemental logging in the Oracle source database. AWS DMS requires supplemental logging to be enabled on the Oracle source database for ongoing replication (CDC). Supplemental logging ensures that the redo logs contain sufficient information (e.g., primary key, unique key, or all column values) to reconstruct the changes for DMS to capture and apply to the target. Without it, DMS cannot generate the necessary log-based change data for CDC.

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Configure DMS to use only full load without CDC

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Disable archive logging on the Oracle source

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Enable binary logging on the Oracle source

Question 10

A company is deploying a new Amazon DynamoDB table with on-demand capacity. The table will store session data for a web application. Which THREE features should be enabled to improve performance and durability?

Accepted Answer

DynamoDB Accelerator (DAX). For an on-demand DynamoDB table, Auto scaling is not applicable because on-demand mode automatically scales throughput. To improve performance, use DynamoDB Accelerator (DAX) which provides an in-memory cache for microsecond read latency. For durability, enable Point-in-time recovery (PITR) for continuous backups and Global tables for multi-region replication, which also provides disaster recovery and low-latency global reads. Time to Live (TTL) helps manage data lifecycle but does not directly improve performance or durability.

Answer

Auto scaling

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Time to Live (TTL)

Question 11

A company is migrating an on-premises PostgreSQL database to Amazon RDS for PostgreSQL. They need to minimize downtime and ensure data consistency. Which TWO methods can be used together to achieve this?

Accepted Answer

Use AWS DMS with full load and CDC. AWS DMS with full load and Change Data Capture (CDC) enables a zero-downtime migration by first copying the existing data (full load) and then continuously replicating ongoing changes from the on-premises PostgreSQL source to the Amazon RDS for PostgreSQL target. This ensures data consistency because CDC captures transactions in near real-time using the PostgreSQL logical replication slot mechanism, allowing the target to stay synchronized until the cutover.

Answer

Take a file system snapshot and copy to Amazon EBS

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Use pg_dump and pg_restore

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Export data to Amazon S3 and import using COPY

Question 12

A company is migrating a 2 TB PostgreSQL database from on-premises to Amazon RDS for PostgreSQL with minimal downtime. The database is continuously updated. Which migration strategy should be used?

Accepted Answer

Use AWS Database Migration Service (DMS) with ongoing replication from an on-premises source.. AWS DMS supports ongoing replication (change data capture, CDC) from an on-premises PostgreSQL source to Amazon RDS for PostgreSQL, enabling minimal downtime migration. The 2 TB size is well within DMS's capabilities, and CDC captures incremental changes after the full load, allowing near-zero downtime cutover.

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Use AWS Schema Conversion Tool (SCT) and AWS Snowball to transfer data.

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Use AWS Database Migration Service with a full load only, then cut over.

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Use pg_dump and pg_restore during a maintenance window.

Question 13

A company is migrating a 500 GB Oracle database to Amazon Aurora PostgreSQL. They need to convert the schema and migrate the data. The application uses Oracle-specific features like hierarchical queries and stored procedures. Which combination of services should they use?

Accepted Answer

Use AWS Schema Conversion Tool (SCT) to convert the schema and AWS Database Migration Service (DMS) to migrate the data.. AWS SCT converts Oracle-specific schema objects (including hierarchical queries and stored procedures) to PostgreSQL-compatible code, while AWS DMS handles the ongoing data migration with minimal downtime. This combination is the standard AWS approach for heterogeneous database migrations, as SCT addresses schema conversion and DMS handles data transfer.

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Use AWS Snowball Edge to transfer the database files and then use SCT to convert the schema.

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Use AWS Database Migration Service (DMS) with the Oracle as source and Aurora PostgreSQL as target.

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Use AWS Schema Conversion Tool (SCT) to convert the schema and then manually export/import data.

Question 14

A company is deploying a new web application and needs a fully managed relational database with automatic failover and read replicas. Which AWS service should they choose?

Accepted Answer

Amazon RDS for MySQL with Multi-AZ deployment. Amazon RDS for MySQL with Multi-AZ deployment provides a fully managed relational database service that automatically provisions and maintains a synchronous standby replica in a different Availability Zone. In the event of a failure, Amazon RDS automatically fails over to the standby, ensuring high availability. Additionally, RDS for MySQL supports read replicas for offloading read traffic, which meets the requirement for both automatic failover and read replicas.

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Amazon DynamoDB

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Amazon EC2 with self-managed MySQL

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Amazon Redshift

Question 15

A company is migrating a self-hosted MongoDB database to Amazon DocumentDB. They need to ensure that indexes are created after the data load to improve migration performance. Which migration strategy should they use?

Accepted Answer

Use AWS Database Migration Service (DMS) with the 'lob' mode set to 'Don't include LOB columns' and create indexes after the full load.. AWS DMS can be configured to skip LOB columns during the full load, which significantly improves migration performance by reducing data transfer overhead. After the full load completes, indexes can be created on the target DocumentDB database, avoiding the performance penalty of maintaining indexes during the bulk data ingestion. This approach aligns with the requirement to defer index creation until after the data load.

Answer

Use AWS Schema Conversion Tool (SCT) to convert the schema and then load data with DMS.

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Use AWS DMS with 'create indexes before data load' option enabled.

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Use mongodump and mongorestore with the --writeConcern option set to 0.