AWS Certified Database Specialty DBS-C01 DBS-C01 Questions 1726–1730 | Page 24/24

1726

MCQeasy

A database administrator needs to automate the backup process for an Amazon RDS for MySQL DB instance. The backups must be retained for 30 days and should be taken daily. Which AWS service should be used to implement this automation?

A.Amazon S3 lifecycle policies

B.AWS Backup

C.AWS Lambda with custom scripts

D.Amazon RDS automated backups

AnswerD

RDS automated backups can be enabled with a retention period of up to 35 days and perform daily backups automatically.

Why this answer

Amazon RDS automated backups are the native, built-in mechanism for backing up RDS DB instances. They automatically take daily snapshots during the backup window and retain transaction logs for point-in-time recovery. By default, the retention period can be set from 1 to 35 days, so configuring it to 30 days meets the requirement without any additional services or custom scripting.

Exam trap

The trap here is that candidates may over-engineer the solution by choosing AWS Backup or Lambda, not realizing that RDS automated backups natively support daily backups with a configurable retention period up to 35 days, making them the simplest and most appropriate choice.

How to eliminate wrong answers

Option A is wrong because Amazon S3 lifecycle policies manage the transition and expiration of objects stored in S3 buckets, not the scheduling or retention of RDS backups. Option B is wrong because AWS Backup is a centralized backup service that can back up RDS instances, but it is not required for this simple automation—RDS automated backups already provide daily backups with configurable retention natively. Option C is wrong because while AWS Lambda with custom scripts could be used to trigger manual snapshots, it adds unnecessary complexity and operational overhead when the built-in automated backup feature of RDS directly satisfies the requirement.

Full explanation →

1727

Multi-Selectmedium

A company is migrating a 2 TB MySQL database to Amazon Aurora MySQL. They need to minimize downtime and ensure data consistency. Which TWO actions should they take? (Choose two.)

Select 2 answers

A.Export data using mysqldump and import into Aurora during a maintenance window.

B.Use AWS Schema Conversion Tool (SCT) to convert the schema to Aurora MySQL.

C.Create an Amazon Aurora MySQL read replica from an Amazon RDS MySQL DB instance.

D.Use AWS Database Migration Service (DMS) with change data capture (CDC) to migrate data.

E.Enable binary logging (binlog) on the source RDS MySQL instance and set up replication to Aurora.

AnswersC, E

Creating an Aurora read replica from RDS MySQL allows near-zero downtime migration.

Why this answer

Options A and C are correct. A: Creating an Aurora read replica from an RDS MySQL snapshot is a common migration approach with minimal downtime. C: Enabling binlog replication from RDS MySQL to Aurora allows continuous replication.

Option B (DMS with CDC) is also valid but not listed as correct? Actually DMS is also valid, but the question expects A and C. Option D (SCT) is for schema conversion, not needed for MySQL to Aurora. Option E (Snowball) is for large data, but not minimal downtime.

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1728

MCQmedium

A company is using Amazon RDS for MySQL with Multi-AZ deployment. The database experiences a failover event, and after failover, the application reports increased latency. Which action should the database specialist take to diagnose the issue?

A.Check Amazon CloudWatch metrics for Database Connections and Latency, and verify DNS resolution.

B.Promote the secondary instance to primary manually.

C.Create a new read replica and redirect traffic.

D.Force a reboot of the DB instance to reset connections.

AnswerA

Monitoring metrics and DNS can pinpoint the cause of increased latency.

Why this answer

Option B is correct because after a failover, the DNS record is updated to point to the new primary, but the application may be using cached DNS. Checking CloudWatch metrics for connection counts and latency can help identify the issue. Option A is wrong because forcing a reboot would not resolve DNS caching.

Option C is wrong because RDS manages the secondary instance automatically. Option D is wrong because restoring from backup is unnecessary.

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1729

MCQhard

A logistics company operates a fleet tracking system using Amazon DocumentDB (with MongoDB compatibility). The database stores location updates from thousands of vehicles every second. The collection has a compound index on (vehicle_id, timestamp). Recently, the company noticed that write latency has increased, and the primary instance's CPU is consistently above 80%. The storage is gp2, and the instance is a db.r5.large. The operations team suspects that index maintenance is causing high CPU. The database administrator needs to reduce write latency without sacrificing query performance for real-time location queries. What should the administrator do?

A.Remove the compound index and rely on the default _id index for queries.

B.Upgrade to a larger instance class, such as db.r5.xlarge, to provide more CPU and memory.

C.Disable journaling to reduce write I/O.

D.Shard the collection using a hash-based shard key on vehicle_id to distribute write load.

AnswerD

Sharding distributes writes and reduces the size of indexes on each shard, lowering maintenance overhead.

Why this answer

Option D is correct because using a hash-based shard key on vehicle_id distributes writes evenly and reduces index maintenance overhead. Option A is wrong because turning off journaling reduces durability, not index maintenance. Option B is wrong because increasing instance size adds CPU but does not address the root cause.

Option C is wrong because removing the compound index harms query performance.

Full explanation →

1730

MCQeasy

A company wants to migrate an on-premises Oracle database to Amazon Aurora PostgreSQL. They need to convert the schema and code. Which AWS service should they use?

A.AWS Schema Conversion Tool (SCT)

B.AWS Lambda

C.Amazon S3

D.AWS Database Migration Service (DMS)

AnswerA

Converts schema and code.

Why this answer

AWS SCT is designed for schema and code conversion between heterogeneous databases. Option A is correct. Option B (DMS) migrates data, not schema.

Option C (S3) is storage. Option D (Lambda) is compute.

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AWS Certified Database Specialty DBS-C01 (DBS-C01) — Questions 1726–1730