Query Analysis with EXPLAIN ANALYZE
Prefix every slow query with EXPLAIN ANALYZE. Look out for Seq Scan, Nested Loop, and high cost values.
Indexing Strategies
B-tree (default): equality and range queries. GIN: full-text search, JSONB, arrays. GiST: geometric and range data. Partial index: indexes only rows matching a condition.
Connection Pooling
Each connection consumes about 10MB of RAM. Use PgBouncer or an application-level pool. Do not set max_connections higher than you really need.
Vacuum and Autovacuum
PostgreSQL uses MVCC — DELETE and UPDATE leave dead tuples behind. VACUUM reclaims them. Never disable autovacuum; tune its parameters instead.
Baseline postgresql.conf Tuning
Conclusion
PostgreSQL tuning boils down to four moves: find the bottleneck with EXPLAIN, add the right index, use a connection pool, and tune autovacuum. Those four steps solve the majority of performance issues KEYDAL sees in production.