Optimizing Database Performance: A Deep Dive

Modern applications live and die by their data layer. In this guide, I share strategies I use to consistently achieve 5-10x performance improvements in production systems.

Core Principles

1. Index the access paths you actually use

2. Keep hot paths in memory

3. Avoid N+1 patterns with careful query planning

4. Profile before you optimize

Indexing Strategy

Composite Indexes

Create indexes that match your most common WHERE + ORDER BY patterns.

Partial Indexes

Use partial indexes for high-selectivity subsets (e.g., active users, recent orders).

Query Optimization

Batch Reads and Writes

Group related operations to reduce round-trips and lock contention.

Materialized Views

Pre-compute expensive aggregates and refresh on a schedule.

Caching Layer

Combine application-level caching (e.g., Redis) with database caching. Cache invalidation should be explicit and event-driven.

Observability

Track p50/p95/p99 latencies, slow queries, and index usage over time. Use these to drive continuous improvements.

Conclusion

The most effective optimizations are workload-specific. Measure, iterate, and let your data guide you.

Published on January 5, 2024