PostgreSQL is powerful, flexible, and—if you misconfigure it—subtly unforgiving. Whether you’re running a single-app database or managing a fleet of replicas, following clear PostgreSQL best practices saves time (and panic) later. In my experience, most performance and reliability issues come from a few avoidable mistakes: bad indexes, neglected maintenance, and reckless configuration changes. This article walks through practical, beginner-friendly, and intermediate-level best practices for performance tuning, indexing, backup and restore, replication, and day-to-day maintenance.
Start with the right mindset
You don’t need to be an expert to get reliable results. Focus on three things first: correct data modeling, realistic workload testing, and observability. Sound boring? Maybe. Effective? Absolutely.
Data modeling: conventions that matter
Keep schemas logical. Use meaningful names. Avoid serializing complex data into single text blobs unless you have a clear reason. From what I’ve seen, well-modeled data reduces the need for expensive workarounds later.
Test with real-ish data
Benchmarks are only useful if the data distribution and query mix resemble production. Try a staging dataset that mirrors row counts, cardinality, and index selectivity.
Performance tuning essentials
Performance in PostgreSQL is mostly about configuration, indexes, and queries. A few knobs provide the biggest wins.
Configuration pointers
- shared_buffers: Set to ~25% of available RAM for dedicated DB servers.
- work_mem: Tune per-session memory for sorts and hashes; too high and you risk OOM.
- maintenance_work_mem: Increase during bulk loads or index builds.
- effective_cache_size: Hint for planner; set to the OS cache size plus shared_buffers.
- max_connections: Prefer a connection pooler (pgBouncer) over huge connection counts.
These are starting points; always measure. See the official docs for details on each parameter: PostgreSQL Documentation.
Use observability: pg_stat_statements and more
Install pg_stat_statements. I can’t stress this enough. It shows the slowest queries by total time. Combine with system metrics (CPU, I/O, memory) and you’ll find low-hanging fruit fast.
Indexing strategies
Indexes speed reads and slow writes. Think carefully. Here are practical rules I use every day.
- Index columns used in WHERE, JOIN, ORDER BY, and GROUP BY.
- Prefer single-purpose indexes; multi-column indexes should match query predicates order.
- Avoid indexing low-selectivity boolean or near-constant columns.
- Use partial indexes for sparse conditions: they’re tiny and fast.
Common index types and when to use them
| Type | Best for | Notes |
|---|---|---|
| B-tree | Equality and range queries | Default; most queries |
| GIN | Full-text and array containment | Great for jsonb & text search |
| GiST | Geospatial and custom types | Used by PostGIS |
Vacuuming, autovacuum, and bloat
PostgreSQL uses MVCC. That means dead rows accumulate and must be reclaimed. Autovacuum helps, but you need to tune it.
- Monitor table bloat with pg_stat_user_tables and autovacuum logs.
- Raise autovacuum frequency for high-churn tables.
- Use VACUUM FULL rarely—prefer pg_repack if you need online compaction.
Backups and restore strategies
Backups are insurance. Test restores. Don’t assume backups work because they ran. I once watched a failed restore at 2am—unpleasant and avoidable.
Practical backup plan
- Use base backups + WAL archiving for point-in-time recovery (PITR).
- Automate regular logical dumps (pg_dump) for schema-level snapshots.
- Encrypt backups in transit and at rest.
- Document and test a restore playbook quarterly.
For an authoritative guide on backup and PITR, reference the official docs: Continuous Archiving and Point-in-Time Recovery.
Replication & high availability
Replication is straightforward but your HA story depends on failover automation and monitoring.
Options
- Streaming replication for near-real-time replication.
- Logical replication for selective replication between major versions.
- Use a cluster manager (Patroni, repmgr) for automated failover; avoid manual switchover in big setups.
Security basics
Security is more than roles and passwords. Protect the data plane and the control plane.
- Use SSL/TLS for client connections.
- Follow least-privilege for roles and extensions.
- Keep Postgres patched and monitor CVEs.
Operational tips: automation and testing
Automate routine tasks: backups, failover tests, schema migrations, and monitoring alerts. Use migrations with version control (pg-migrate, Flyway, Liquibase).
Schema changes without downtime
Use online-friendly migrations: CREATE INDEX CONCURRENTLY, ADD COLUMN with defaults as nullable plus a backfill step, and avoid long locks in peak hours.
Common pitfalls and how to avoid them
- Over-indexing: slows writes and wastes space. Keep indexes purposeful.
- Ignoring autovacuum: bloat and slow queries follow.
- Too many connections: use a pooler to avoid memory pressure.
- Relying only on logical backups: they don’t replace PITR for corruption scenarios.
Real-world checklist (quick wins)
- Enable pg_stat_statements and review top 10 slow queries weekly.
- Set up WAL archiving and test PITR.
- Deploy a connection pooler like pgBouncer for web apps.
- Monitor autovacuum activity and tune thresholds for hot tables.
- Document your recovery runbook and test it.
Further reading and recommended docs
If you want to go deeper, the PostgreSQL project documentation is the canonical source and very practical: PostgreSQL Documentation. For a quick historical overview, see PostgreSQL on Wikipedia. If you’re running Postgres on AWS, their guidance for RDS Postgres contains useful operational notes: Amazon RDS for PostgreSQL.
Final thoughts
Good Postgres operations are iterative: measure, change one thing, measure again. Start small—reasonable configuration, sensible indexes, backups you’ve tested—and build up. What I’ve noticed: teams that prioritize observability and repeatable playbooks sleep better. And isn’t that worth a few config tweaks?
Frequently Asked Questions
Start with shared_buffers, work_mem, maintenance_work_mem, effective_cache_size, and max_connections. Tune them based on available memory and workload, and measure before/after changes.
Autovacuum should handle most workloads; increase its frequency for high-churn tables. Monitor table bloat and run manual VACUUM or pg_repack only when necessary.
Use base backups plus WAL archiving for point-in-time recovery (PITR), supplement with regular logical dumps (pg_dump), encrypt backups, and regularly test restores.
Use streaming replication for near-real-time physical replication; use logical replication when you need selective replication, cross-version replication, or row-level filtering.
Use a connection pooler like pgBouncer to limit database connections and reduce per-connection memory overhead. Also tune max_connections to realistic values.