Database Design for Web Applications: PostgreSQL Best Practices

Database decisions made in week one of a project determine the application's performance ceiling for years to come. PostgreSQL is our database of choice at Jumpframe, and these practices guide every schema we design.
Normalize first, denormalize with evidence. Start with a properly normalized schema — no duplicate data, clear relationships, single source of truth for each fact. Only denormalize when you have measured proof that a specific query pattern requires it. Premature denormalization creates update anomalies that are far harder to fix than slow queries.
Index strategically. Every query that appears in a WHERE clause, JOIN condition, or ORDER BY should have an index. But don't index everything — each index slows down writes and consumes storage. Use EXPLAIN ANALYZE to identify which indexes your actual query patterns need.
Use appropriate data types. UUIDs for primary keys (prevents enumeration attacks and works across distributed systems). Timestamps with timezone for all temporal data. Text for variable-length strings (VARCHAR offers no performance advantage in PostgreSQL). Enums or check constraints for fields with limited valid values.
Design for queries, not for objects. Your database schema should serve the application's access patterns, not mirror your object model. If you always query orders with their line items, consider whether your join pattern is efficient or whether restructuring would help.
Plan for migration. Use a migration tool (Drizzle, Prisma, Flyway) from day one. Every schema change should be a versioned, reversible migration. Manual ALTER TABLE statements in production are how data gets lost.
Monitor query performance continuously. Slow queries don't announce themselves — they creep in as data grows. pg_stat_statements identifies the queries consuming the most time, often revealing optimization opportunities that take minutes to fix.


