Question 330
During an AWS global infrastructure design review, the decisive constraint is: A slow SQL query scans millions of rows despite narrow search predicates. Which approach meets the stated objective with the least unnecessary complexity?
Explanation
Correct Answer
Add appropriate indexes and benchmark query plans before scaling instances. Better execution plans can reduce I/O far more than adding compute capacity.
Incorrect Answers
This alternative, Inspect CloudWatch Database Insights wait events and I/O saturation, is appropriate when A relational database's average CPU is low but client requests stall waiting on storage reads. Database wait analysis identifies I/O bottlenecks that CPU metrics alone can miss.
For the separate situation An RDS database's transactional reads grow rapidly while writes remain steady, Add appropriate read replicas and route read-only queries away from the writer could be useful. Read scaling isolates analytics and reads from transactional write load.
Add RDS Proxy and control client connection concurrency solves the related scenario A database experiences rising connection counts during Lambda traffic spikes; rDS Proxy pools application connections to reduce database connection pressure.