AWS Certified Solutions Architect – Associate (SAA-C02) — Question 31

A company's website is using an Amazon RDS MySQL Multi-AZ DB instance for its transactional data storage. There are other internal systems that query this DB instance to fetch data for internal batch processing. The RDS DB instance slows down significantly when the internal systems fetch data. This impacts the website's read and write performance, and the users experience slow response times.
Which solution will improve the website's performance?

Answer options

• A. Use an RDS PostgreSQL DB instance instead of a MySQL database.
• B. Use Amazon ElastiCache to cache the query responses for the website.
• C. Add an additional Availability Zone to the current RDS MySQL Multi-AZ DB instance.
• D. Add a read replica to the RDS DB instance and configure the internal systems to query the read replica.

Correct answer: D

Explanation

The correct answer is D because adding a read replica allows the internal systems to offload their read queries from the main database, thus improving performance for the website. Option A is incorrect as switching to PostgreSQL would not inherently solve the performance issues. Option B, while helpful for caching, does not address the direct load on the database. Option C does not alleviate the query load either, as it only provides redundancy, not performance enhancement.