AWS Certified Database – Specialty — Question 246

A company recently created a snapshot of an Amazon RDS for PostgreSQL DB instance that hosts a production database. The company created a new DB instance from the snapshot to test a new application feature while providing isolation from the production database.

During testing of the new application feature, the company noticed that read latency on the new database was higher than normal. A database specialist needs to resolve the latency issue.

Which solution will meet these requirements with the MOST operational efficiency?

Answer options

• A. Log in to the database by using the PostgreSQL administration tool. Issue a SELECT * command against each table in the database.
• B. Create a new parameter group and set the max_connections parameter to 100. Assign the parameter group to the new database. Apply the changes immediately.
• C. Edit the default parameter group for the matching PostgreSQL engine. Set the max_connections parameter to 100. Reboot the new database to pick up the changes to the parameter group.
• D. Login to the database by using the PostgreSQL administration tool. Issue the VACUUM (ANALYZE, DISABLE_PAGE_SKIPPING) command.

Correct answer: D

Explanation

The correct answer is D because issuing the VACUUM command helps reclaim storage space and optimizes database performance, effectively addressing read latency issues. Options A, B, and C do not directly target the root cause of latency; simply running a SELECT command or adjusting connection parameters will not resolve the underlying performance degradation.