DBS-C01 Deployment and Migration Practice Question
A company is migrating a 5 TB PostgreSQL database from on-premises to Amazon RDS for PostgreSQL. The database has a 24/7 uptime requirement and must be migrated with minimal downtime. The on-premises network bandwidth is 100 Mbps. The migration must be completed within 48 hours. The team has chosen to use AWS Database Migration Service (DMS) with ongoing replication from a change data capture (CDC) source. After setting up the source endpoint, target endpoint, and replication instance, the initial full load takes 30 hours. However, during the CDC phase, the target falls behind by over 2 hours and continues to lag. The replication instance is a dms.c5.large (2 vCPUs, 4 GB memory). The source database is heavily utilized with frequent updates. What should the team do to reduce the CDC lag and meet the migration deadline?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Increase the replication instance size to dms.c5.2xlarge.
Increasing the replication instance size to dms.c5.2xlarge provides more CPU and memory, which can handle higher transaction throughput, reducing CDC lag. Option B is wrong because enabling Multi-AZ on a replication instance does not directly improve performance; it adds redundancy and can even introduce latency. Option C is wrong because splitting the migration into multiple tasks for a single source database adds overhead and may cause conflicts, and it does not necessarily reduce lag. Option D is wrong because disabling ongoing replication would result in data loss and does not meet the minimal downtime requirement.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Increase the replication instance size to dms.c5.2xlarge.
Why this is correct
Increasing the replication instance size provides more CPU and memory, allowing it to process CDC changes faster and reduce lag.
- ✗
Enable Multi-AZ on the replication instance for better performance.
Why it's wrong here
Enabling Multi-AZ on a replication instance does not directly improve performance; it adds redundancy and can even introduce latency.
- ✗
Split the migration into multiple DMS tasks for parallel processing.
Why it's wrong here
Splitting the migration into multiple tasks for a single source database adds overhead and may cause conflicts, not reducing lag effectively.
- ✗
Disable ongoing replication and use a one-time full load migration.
Why it's wrong here
Disabling ongoing replication would cause data loss and does not meet the minimal downtime requirement.
Go deeper
Related to this question
About these practice questions
This DBS-C01 question is part of Courseiva's 1,663-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DBS-C01 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the DBS-C01 exam.