When your queries are crawling and you're staring at EXPLAIN output trying to figure out why, this walks you through the full optimization cycle: baseline metrics, execution plan analysis, index design, and validation. It covers both PostgreSQL and MySQL with practical SQL examples for finding slow queries, reading execution plans, and creating covering indexes. The workflow is methodical about measuring before and after, testing changes incrementally, and catching things like stale statistics or low buffer cache hits. The reference tables for interpreting EXPLAIN patterns are genuinely handy. Just know it's focused on query and index optimization rather than infrastructure scaling or replication tuning.
npx skills add https://github.com/jeffallan/claude-skills --skill database-optimizer