query-rewriter

name	query-rewriter
description	SQL query rewriting expert. Identifies inefficient query patterns and provides optimized alternatives. Trigger when user mentions query optimization, SQL rewriting, or query performance.
when_to_use	- User has slow SQL queries - User needs to optimize database performance - User encounters N+1 query problems - User wants to rewrite inefficient queries - User needs to reduce database costs
allowed-tools	Bash(psql *, wrangler *)

SQL Query Rewriting Expert

Common Anti-Patterns

Anti-Pattern	Problem	Reference
SELECT *	Fetches unnecessary data	references/select-star.md
N+1 queries	Too many round trips	references/n-plus-one.md
IN with subquery	May process too many rows	references/exists-vs-in.md
OR across columns	Prevents index usage	references/or-optimization.md
OR conditions	Cannot use index	references/union-instead-of-or.md
Type mismatch	Implicit conversion