DEA-C01 Data Store Management Practice Question
A data engineer needs to set up a new Amazon RDS for PostgreSQL database for a production workload. The database must be highly available and resilient to a single Availability Zone failure. Which configuration should the engineer choose?
⚠ Common exam trap
It's easy for candidates to confuse Multi-AZ with read replicas, assuming that a read replica can serve as a failover target, but in RDS PostgreSQL, read replicas are asynchronous and require manual promotion, making them unsuitable for automatic high availability against AZ failures.
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
✓
Multi-AZ deployment with one standby in a different AZ
A Multi-AZ deployment for Amazon RDS PostgreSQL automatically provisions and maintains a synchronous standby replica in a different Availability Zone. This configuration provides automatic failover in the event of an AZ failure, ensuring high availability and resilience without manual intervention. The synchronous replication ensures zero data loss during failover, which is critical for production workloads.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Single-AZ with automated backups
Why it's wrong here
Automated backups restore to a point in time into a new instance; they do not maintain a standby, so failover is manual and slow. Backups are the right choice for recovery from corruption or accidental deletion, not for surviving an Availability Zone outage without intervention.
- ✓
Multi-AZ deployment with one standby in a different AZ
Why this is correct
Multi-AZ maintains a synchronous standby replica in a separate Availability Zone, so RDS automatically fails over to it if the primary AZ fails. This directly satisfies the resilience-to-single-AZ-failure constraint, unlike a single-AZ instance or read replicas, which use asynchronous replication and do not provide automatic failover.
- ✗
Multi-AZ with two readable standbys
Why it's wrong here
Two readable standbys provide additional read capacity and higher durability, but this configuration targets read scaling and multi-AZ resilience beyond a single AZ failure. A single standby already satisfies the stated requirement, and two standbys add cost without addressing a different need.
- ✗
Single-AZ with a read replica
Why it's wrong here
A read replica is asynchronous and cannot be promoted automatically, so an AZ failure causes data loss and manual failover, not resilience. It is tempting because read replicas offload reporting queries and can be promoted manually during DR drills, but they serve read scaling rather than automatic failover.
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About these practice questions
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Same concept, more angles
1 more way this is tested on DEA-C01
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A data engineering team is migrating a MySQL database to Amazon RDS for MySQL. They need to ensure high availability and automated failover. Which THREE configurations should they implement?
easy- A.Enable Enhanced Monitoring.
- ✓ B.Enable automated backups with a retention period.
- ✓ C.Enable Multi-AZ deployment.
- ✓ D.Configure a DB subnet group with subnets in at least two Availability Zones.
- E.Create a read replica in a different region.
Why B: Option B is correct because enabling automated backups with a retention period is required for RDS to support point-in-time recovery and is a prerequisite for Multi-AZ failover operations, ensuring data durability and recoverability during a failover event. Option C is correct because a Multi-AZ deployment maintains a synchronous standby replica in a different Availability Zone and provides automatic failover to that standby if the primary DB instance fails, directly satisfying the high availability and automated failover requirement. Option D is correct because a Multi-AZ DB instance requires a DB subnet group that spans at least two Availability Zones, which is the networking foundation that allows RDS to place the primary and standby instances in separate AZs. Option A is not correct because Enhanced Monitoring only provides granular OS-level metrics (via the RDS monitoring agent) and does not contribute to high availability or failover. Option E is not correct because a cross-region read replica is used for disaster recovery and read scaling, not for automatic failover of the primary DB instance within the Multi-AZ high-availability design.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DEA-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 DEA-C01 exam.