# The Complete PostgreSQL Performance Guide
## Introduction
PostgreSQL is the backbone of most modern applications. This guide covers optimization techniques that actually move the needle.
## Configuration Tuning
### Memory Settings
“`sql
shared_buffers = 256MB — 25% of RAM
effective_cache_size = 768MB
work_mem = 16MB
maintenance_work_mem = 128MB
“`
### Connection Pooling
Use PgBouncer or PgPool for connection management.
## Query Optimization
### Analyze Query Plans
“`sql
EXPLAIN ANALYZE
SELECT * FROM orders WHERE user_id = 123;
“`
### Key Index Strategies
– B-tree for equality queries
– GIN for full-text search
– BRIN for time-series data
## Monitoring
“`sql
— Slow queries
SELECT query, calls, mean_time
FROM pg_stat_statements
ORDER BY mean_time DESC
LIMIT 10;
“`
## Conclusion
PostgreSQL performance requires understanding your workload. Start with configuration, then optimize queries.