Database Optimization: How I Reduced Query Time by 85%

1. Index Strategy Matters More Than You Think

Covering indexes, composite index ordering, and understanding the difference between B-tree and hash indexes transformed our query performance.

2. Query Pattern Analysis

Using EXPLAIN ANALYZE regularly revealed that our "optimized" queries were doing full table scans on tables with millions of rows.

3. Connection Pooling Is Non-Negotiable

At scale, creating a new database connection per request becomes a bottleneck. PgBouncer and ProxySQL became essential infrastructure.

Results

Combined, these changes reduced our p99 query time from 850ms to 127ms—a 85% improvement that directly impacted user experience.