AWS Certified Solutions Architect – Associate (SAA-C02) — Question 694

A company is developing an internal application that uses a PostgreSQL database. The company decides to host the database on Amazon Aurora. The application does not need to be highly available, but data must be stored in multiple Availability Zones.
Which database configuration meets these requirements MOST cost-effectively?

Answer options

• A. An Aurora PostgreSQL global database cluster
• B. An Aurora PostgreSQL DB cluster that has a single DB instance
• C. An Aurora PostgreSQL DB cluster that has a primary DB instance and a read replica
• D. Two Aurora PostgreSQL DB clusters, with each DB cluster in a separate Availability Zone

Correct answer: B

Explanation

Amazon Aurora automatically replicates data across three Availability Zones at the storage layer, even if the cluster contains only a single DB instance. Since high availability is not required, deploying a single-instance Aurora DB cluster is the most cost-effective option because it avoids the compute costs of extra instances. Options involving read replicas, global databases, or multiple clusters would incur unnecessary additional costs.