Friday, February 6, 2026
Database Query Optimization Under Load
Our application experiences performance degradation during peak traffic. Specifically, queries against our PostgreSQL database show significant latency spikes. We need to optimize query performance to meet our SLA of 99th percentile latency under 200ms. Can you walk me through your approach to diagnosing and optimizing these queries?
00The Situation
We have a high-traffic application with 1 million daily active users. At peak times, we process about 10,000 queries per second (QPS) on our database. Current p99 latency is averaging 450ms, which is unacceptable. We want to scale effectively while keeping costs manageable.
Let's start with how you would approach diagnosing this issue.
Clarify Requirements
5 minutes
Gather detailed information about the system, required performance metrics, and operational constraints.
Think about this first
What specific metrics are you looking to optimize?