Database Design

This is a solid reference for PostgreSQL schema design and migrations, with practical examples for indexing strategies, normalization tradeoffs, and zero-downtime deployments. The code snippets are actually useful, showing things like partial indexes, covering indexes, and the right way to use EXPLAIN ANALYZE. The migration patterns section is probably the most valuable part, walking through the five-step process for changing columns without downtime. It focuses heavily on Postgres with some general SQL principles, so if you're deep in MySQL or NoSQL you'll need to adapt. The query optimization section covers the classics like EXISTS over IN and cursor-based pagination. Good for mid-level developers who know SQL basics but haven't spent years optimizing production databases.