Postgresql

This walks Claude through PostgreSQL schema design with opinionated best practices baked in. It covers the practical stuff: when to use BIGINT GENERATED ALWAYS AS IDENTITY versus UUID, why you need to manually index foreign keys, how to pick between JSONB and proper columns, and which data types to avoid entirely (no VARCHAR, no TIMESTAMP without timezone, no SERIAL). The normalize-first rule is solid, and the gotchas section actually explains MVCC and sequence gaps instead of glossing over them. Use this when you're designing tables from scratch or reviewing a schema for performance and maintainability. It's thorough without being academic, and it'll stop you from making the common mistakes that bite you six months later.