SAP-C02 Continuous Improvement for Existing Solutions Practice Question

A company has a web application that uses an Amazon RDS for PostgreSQL database. The database is experiencing high read traffic, and the application is seeing increased latency. The database is currently a Single-AZ deployment with a db.r5.2xlarge instance. The company wants to improve read performance and also increase availability with minimal application changes. Which solution should a solutions architect recommend?

⚠ Common exam trap

Test-takers frequently confuse Multi-AZ with read scaling; Multi-AZ provides failover, not read capacity, and Performance Insights only monitors.

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

✓

Create a read replica of the RDS instance and modify the application to direct read queries to the read replica endpoint.

Adding a read replica to the existing RDS instance and directing read queries to it offloads read traffic and improves performance. This requires minimal application changes—just pointing read queries to the replica endpoint. It also enhances availability because the replica can be promoted. Other options either do not serve reads, require more changes, or involve migration.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

✗
Enable Amazon RDS Performance Insights to identify and optimize slow queries.
Why it's wrong here
Performance Insights helps diagnose performance issues but does not directly improve read performance or availability. It is a monitoring tool that provides visibility into database load, but it does not add read capacity or redundancy. While useful for optimization, it does not meet the immediate need for scaling reads and increasing availability.
✗
Migrate the database to Amazon Aurora PostgreSQL with a reader endpoint and update the application to use the reader endpoint for read queries.
Why it's wrong here
Migrating to Aurora PostgreSQL can improve performance and scalability, but it involves a significant migration effort and potential downtime. While Aurora provides a reader endpoint that automatically load-balances across read replicas, the migration itself is not minimal. This option is more complex and costly than simply adding a read replica to the existing RDS instance.
✓
Create a read replica of the RDS instance and modify the application to direct read queries to the read replica endpoint.
Why this is correct
Creating a read replica offloads read traffic from the primary database, improving read performance. Modifying the application to use the read replica endpoint for read queries is a standard pattern and requires minimal changes if the application uses a separate connection for reads. This also improves availability because the read replica can be promoted if the primary fails.
✗
Convert the RDS instance to a Multi-AZ deployment and create a read replica in a different Availability Zone.
Why it's wrong here
Multi-AZ provides a standby replica for failover but does not serve read traffic. Creating a separate read replica in a different AZ can offload reads, but the Multi-AZ standby is not used for reads. This approach increases availability but does not directly improve read performance unless the application is modified to use the read replica endpoint, which requires application changes.

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SAP-C02 Continuous Improvement for Existing Solutions Practice Question

Why each option matters

Option-by-option breakdown

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