Your database is slow. Here's why (and how to fix it):
1/ Most apps handle 10K users easily. But at 1M users? Everything breaks.
The problem isn't your code. It's how your database processes millions of queries per second.
2/ Indexing Mistake #1: Adding indexes everywhere
Each index speeds up reads but slows down writes. You need strategic, composite indexes on your hottest query paths.
Example: Index on (user_id, created_at DESC) beats separate indexes every time.
Your ORM is secretly making 1000 database calls instead of 1.
One query to fetch users â 1000 queries to fetch their posts
Solution: Eager loading & JOINs. Always.
4/ Caching Layer = 10x Performance
95%+ cache hit rate can reduce database load by 10x.
But cache invalidation? That's the hard part.
Time-based expiration vs event-based invalidationâchoose based on consistency needs.
5/ Connection Pools: Size Matters
Too few â bottlenecks Too many â CPU thrashing
Formula: (core_count à 2) + disk_spindles
But always load test for YOUR workload.
Last resort. Only after you've: â
Optimized queries â
Added caching â
Implemented read replicas â
Maxed out vertical scaling
Sharding adds massive complexity. Make sure you need it.
7/ We wrote a complete guide covering all of this (+ execution plans, materialized views, monitoring strategies)
1000 words of actionable techniques.
Check it out on the AvienTech blog đ https://avientech.com/database-optimization-techniques-for-high-traffic-applications/
