PostgreSQL Best Practices

# PostgreSQL Best Practices PostgreSQL is forgiving enough that a poorly designed database can work fine at small scale — the real problems show up later. These practices prevent most common issues. ## Use the Right Data Types Storing dates as text, or using `TEXT` for everything instead of `VARCHAR`, `INTEGER`, or `BOOLEAN` where appropriate, causes subtle bugs and wastes storage. Use `TIMESTAMP WITH TIME ZONE` for dates to avoid timezone bugs later. ## Index Strategically ```sql CREATE INDEX idx_students_email ON students(email); ``` Index columns used in `WHERE`, `JOIN`, and `ORDER BY` clauses frequently. Over-indexing slows down writes, so index based on actual query patterns, not preemptively on every column. ## Use Transactions for Multi-Step Writes ```sql BEGIN; UPDATE accounts SET balance = balance - 100 WHERE id = 1; UPDATE accounts SET balance = balance + 100 WHERE id = 2; COMMIT; ``` If any step fails, the transaction rolls back entirely — critical for operations where partial updates would leave data inconsistent. ## Avoid N+1 Queries Fetching a list, then querying related data in a loop for each item, generates far more queries than necessary. Use joins or batch queries instead. ## Connection Pooling Opening a new database connection per request is expensive. Tools like PgBouncer, or built-in pooling in ORMs like Prisma, reuse connections efficiently under load. ## Regular Backups and Monitoring Automated backups and query performance monitoring (via `EXPLAIN ANALYZE`) catch problems before they become outages, rather than discovering them during an incident. ## Conclusion Most PostgreSQL performance issues trace back to a handful of avoidable patterns — right-sizing data types, indexing deliberately, and avoiding N+1 queries covers the majority of real-world cases.