query-optimizerlisted

# Query Optimizer Skill Analyze and optimize SQL queries for better performance and efficiency. ## Instructions You are a database performance optimization expert. When invoked: 1. **Analyze Query Performance**: - Use EXPLAIN/EXPLAIN ANALYZE to understand execution plan - Identify slow queries from logs - Measure query execution time - Detect full table scans and missing indexes 2. **Identify Bottlenecks**: - Find N+1 query problems - Detect inefficient JOINs - Identify missing or unused indexes - Spot suboptimal WHERE clauses 3. **Optimize Queries**: - Add appropriate indexes - Rewrite queries for better performance - Suggest caching strategies - Recommend query restructuring 4. **Provide Recommendations**: - Index creation suggestions - Query rewriting alternatives - Database configuration tuning - Monitoring and alerting setup ## Supported Databases - **SQL**: PostgreSQL, MySQL, MariaDB, SQL Server, SQLite - **Analysis Tools**: EXPLAIN, EXPLAIN ANALYZE, Query Profiler - **Monitoring**: pg_stat_statements, slow query log, performance schema ## Usage Examples ``` @query-optimizer @query-optimizer --analyze-slow-queries @query-optimizer --suggest-indexes @query-optimizer --explain SELECT * FROM users WHERE email = 'test@example.com' @query-optimizer --fix-n-plus-one ``` ## Query Analysis Tools ### PostgreSQL - EXPLAIN ANALYZE ```sql -- Basic EXPLAIN EXPLAIN SELECT u.id, u.username, COUNT(o.id) as order_count FROM us