DBS-C01 Practice Test 28 — 15 Questions

Question 1

A company is migrating an on-premises MySQL database to Amazon RDS for MySQL. The database uses InnoDB tables and is 500 GB in size. The migration must be completed within a 2-hour maintenance window. Which approach is MOST likely to meet the requirement?

Accepted Answer

Use mysqldump to export the database and then import it into RDS.. Option A is correct because using mysqldump with the --single-transaction flag exports a consistent snapshot without locking tables, and the data can be imported into RDS within the window if network bandwidth is sufficient. Option B is wrong because importing a physical backup from an on-premises database to RDS is not straightforward; RDS does not support backup file import directly. Option C is wrong because AWS DMS requires initial load and may not complete within 2 hours for 500 GB. Option D is wrong because creating a read replica requires the source to be an RDS instance, not on-premises.

Answer

Create a read replica of the on-premises database and promote it to RDS.

Answer

Use AWS DMS with a full load task.

Answer

Take a physical backup of the data directory and copy it to RDS.

Question 2

A company is migrating a 1 TB SQL Server database from on-premises to Amazon RDS for SQL Server. The database has a large table with a LOB column. The network bandwidth between the on-premises data center and AWS is limited to 50 Mbps. The migration must be completed within a week. Which approach should the company use?

Accepted Answer

Use AWS DMS with compression enabled.. Option D is correct because AWS DMS can compress data during transfer, reducing the amount of data sent over the network, and can complete within a week even with a 50 Mbps connection. Option A is wrong because SQL Server native backup and restore requires the backup file to be transferred over the network, which may take too long with 50 Mbps. Option B is wrong because BCP export/import also transfers the entire data over the network. Option C is wrong because creating a read replica is not possible from on-premises.

Answer

Use BCP to export the LOB table to flat files and then import to RDS.

Answer

Use SQL Server native backup and restore to RDS.

Answer

Create a read replica of the on-premises database and promote it.

Question 3

A company is migrating an on-premises MongoDB database to Amazon DocumentDB. The migration must be online with minimal downtime. The source MongoDB is version 4.0 and uses replica sets. Which tool should the company use?

Accepted Answer

Use AWS DMS with MongoDB as source and DocumentDB as target.. Option B is correct because AWS DMS supports MongoDB as a source and DocumentDB as a target, and can perform ongoing replication for minimal downtime. Option A is wrong because mongodump/mongorestore is a logical dump that requires downtime for a consistent snapshot. Option C is wrong because MongoDB Compass is a GUI tool and does not support ongoing replication to DocumentDB. Option D is wrong because creating a read replica from MongoDB to DocumentDB is not supported.

Answer

Use MongoDB Compass to export data and import into DocumentDB.

Answer

Use mongodump and mongorestore.

Answer

Create a read replica of the MongoDB replica set and promote to DocumentDB.

Question 4

A company wants to migrate its on-premises Oracle database to Amazon Aurora PostgreSQL. The company needs to convert the database schema and code from Oracle to PostgreSQL. Which AWS service should they use for schema conversion?

Accepted Answer

AWS Schema Conversion Tool (SCT). Option A is correct because AWS SCT (Schema Conversion Tool) is specifically designed to convert database schemas and code from one engine to another, including Oracle to PostgreSQL. Option B is wrong because AWS DMS focuses on data migration, not schema conversion. Option C is wrong because AWS Database Migration Service is for data migration, not conversion. Option D is wrong because AWS Glue is for ETL, not schema conversion.

Answer

AWS DMS

Answer

AWS Glue

Answer

AWS Database Migration Service

Question 5

A company is migrating a 2 TB Oracle database from on-premises to Amazon RDS for Oracle. The network bandwidth is 100 Mbps. The migration must be completed within 3 days. Which approach is MOST efficient?

Accepted Answer

Use AWS DMS with parallel load and ongoing replication.. Option C is correct because AWS DMS with parallel load can significantly speed up the migration by loading multiple tables simultaneously. Option A is wrong because a single-threaded export/import may not complete within 3 days on 100 Mbps. Option B is wrong because Oracle GoldenGate requires additional licensing and setup. Option D is wrong because RMAN backup and restore requires transferring the full backup over the network.

Answer

Use Oracle RMAN to create a backup and restore to RDS.

Answer

Use Oracle Data Pump with a single export and import.

Answer

Use Oracle GoldenGate for real-time replication.

Question 6

A company is migrating a 500 GB PostgreSQL database from on-premises to Amazon Aurora PostgreSQL. The migration must have a recovery point objective (RPO) of less than 5 minutes and a recovery time objective (RTO) of less than 30 minutes. Which migration strategy should the company use?

Accepted Answer

Use AWS DMS with full load and ongoing replication.. Option B is correct because AWS DMS with ongoing replication can achieve an RPO of less than 5 minutes by continuously replicating changes, and the RTO can be met by cutting over quickly. Option A is wrong because a full backup and restore has an RPO of hours. Option C is wrong because pg_dump export/import has an RPO of the time of the dump. Option D is wrong because creating a read replica from on-premises is not possible.

Answer

Create a read replica of the on-premises database and promote it.

Answer

Take a full backup using pg_basebackup and restore to Aurora.

Answer

Use pg_dump to export the database and import into Aurora.

Question 7

A company wants to migrate a self-hosted MongoDB database to Amazon DocumentDB. They need to convert the schema. Which AWS service should they use?

Accepted Answer

AWS Schema Conversion Tool (SCT). AWS DMS can migrate MongoDB to DocumentDB, and AWS SCT can help convert schemas if needed. However, DocumentDB supports MongoDB wire protocol, so often SCT is not required. But the question asks for schema conversion, so SCT is the correct choice.

Answer

AWS Glue

Answer

AWS Database Migration Service (DMS)

Answer

Amazon Athena

Question 8

A company is deploying a new Amazon RDS for PostgreSQL database. The database will be used by an application that requires read-after-write consistency and low latency. Which deployment configuration is MOST suitable?

Accepted Answer

Deploy with one or more read replicas in the same region. Multi-AZ deployment with synchronous standby provides high availability and data durability, but does not improve read performance. Read replicas (Option B) improve read scalability but may have eventual consistency. Option C (single-AZ) lacks HA. Option D (cross-region) is for DR.

Answer

Deploy with cross-region replicas

Answer

Deploy as a single-AZ instance with increased instance size

Answer

Deploy as Multi-AZ with a synchronous standby

Question 9

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.. Option D (SCT for schema conversion, DMS for data migration) is correct because SCT converts Oracle schema including stored procedures and hierarchical queries, and DMS migrates the data. Option A (DMS only) does not convert schema. Option B (SCT only) does not migrate data. Option C (Snowball with SCT) is for large data transfers but not for ongoing replication or schema conversion of complex features.

Answer

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

Answer

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

Answer

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

Question 10

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.. Options A, B, and D are correct. A: SCT converts the schema. B: DMS with CDC provides minimal downtime. D: Use SCT to assess and convert Oracle-specific features. Option C (modify application to use Aurora-specific features) is not necessary. Option E (Snowball) is not for minimal downtime.

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 11

A company is deploying a new Amazon RDS for MariaDB instance. The database must be accessible from a specific set of EC2 instances in a VPC. How should the company configure security to allow access?

Accepted Answer

Create a security group for the RDS instance that allows inbound traffic from the EC2 instances' security group.. Option C is correct because the RDS security group should allow inbound traffic from the EC2 security group. Option A is wrong because NACLs are stateless and less granular. Option B is wrong because RDS does not support EC2 classic security groups. Option D is wrong because IAM roles are for authentication, not network access.

Answer

Assign the same security group to both the RDS instance and the EC2 instances.

Answer

Attach an IAM role to the EC2 instances that grants access to the RDS database.

Answer

Configure a network ACL to allow inbound traffic from the EC2 instance IPs.

Question 12

A company wants to migrate an on-premises SQL Server database to Amazon RDS for SQL Server. They need to convert stored procedures and functions. Which AWS service should they use?

Accepted Answer

AWS SCT. AWS SCT helps convert database schema and code objects like stored procedures from one engine to another (including SQL Server to RDS for SQL Server for compatibility checks). DMS handles data migration, not schema conversion. CloudEndure is for server migration. Snowball is for offline data transfer.

Answer

AWS CloudEndure Migration

Answer

AWS DMS

Answer

AWS Snowball

Question 13

Refer to the exhibit. A developer wants to connect to the database. Which database engine is most likely being used?

Accepted Answer

MySQL. The output shows port 3306, which is the default port for MySQL and MariaDB. Amazon RDS for MySQL uses port 3306. Aurora MySQL also uses 3306, but the endpoint pattern is RDS, not Aurora-specific. PostgreSQL uses 5432, Oracle uses 1521, SQL Server uses 1433.

Answer

Oracle

Answer

SQL Server

Answer

PostgreSQL

Question 14

A company is migrating a 5 TB Oracle database to Amazon Aurora MySQL using AWS DMS. The full load completes successfully, but the CDC phase is slow and the target Aurora cluster is consuming high CPU. The DMS instance type is dms.c4.2xlarge. Which change will most likely improve CDC performance?

Accepted Answer

Increase the number of parallel apply threads in the DMS task. Option D is correct because increasing the number of parallel apply threads can improve throughput, reducing CPU strain on Aurora. Option A is wrong because increasing max_connections may not help. Option B is wrong because Aurora auto-scales storage. Option C is wrong because DMS uses its own storage, not target storage.

Answer

Increase the Aurora cluster's max_connections parameter

Answer

Increase the DMS task's target storage allocation

Answer

Change the Aurora cluster to a larger instance class

Question 15

A company is migrating a 500 GB MongoDB database to Amazon DocumentDB. The migration must have minimal impact on the source database. Which approach should the company take?

Accepted Answer

Use AWS Database Migration Service (DMS) with MongoDB as source and DocumentDB as target.. AWS DMS supports MongoDB as a source and DocumentDB as a target, with ongoing replication to minimize downtime. Option A (mongorestore) causes high impact. Option C (export/import) causes impact. Option D (AWS SCT) is not for migration itself.

Answer

Use mongodump to export the data, then use mongorestore to import into DocumentDB.

Answer

Use mongoexport to export CSV, then use the DocumentDB import tool.

Answer

Use AWS Schema Conversion Tool (SCT) to convert schema, then copy data.