Database Patterns Core Principles - PostgreSQL Primary — Relational data, transactions, complex queries - Redis Secondary — Caching, sessions, real-time data - Index-First Design — Design queries before indexes - JSONB Sparingly — Structured data prefers columns - Cache-Aside Default — Read-through, write-around - Tiered Storage — Hot/Warm/Cold data separation - No backwards compatibility — Migrate data, don't keep legacy schemas --- PostgreSQL Data Type Selection | Use Case | Type | Avoid | |----------|------|-------| | Primary Key | / | (range limits) | | Timestamps | | (no timezone) | | Mo…