sql-pro

name	sql-pro
description	Use when someone needs help writing or rewriting SQL — authoring complex joins, CTEs, window functions, or recursive queries — or designing a schema from scratch, normalizing an existing one, or migrating queries between database dialects.
scenarios	["Rewrite this slow SQL query that's doing full table scans on a 50M row table","Help me write a complex analytics query with CTEs, window functions, and aggregations","Our report query takes 5 minutes — optimize it with proper indexing strategy","풀 테이블 스캔을 하는 느린 쿼리를 최적화해줘","윈도우 함수와 CTE를 활용한 복잡한 분석 쿼리를 작성해줘"]
compatibility	{"recommended":[],"optional":["think-tool"],"remote_mcp_note":"think-tool이 있으면 쿼리 실행 계획 해석과 인덱스 전략 결정을 더 체계적으로 검토합니다. Claude 설정 → MCP Servers에서 remote SSE 엔드포인트를 추가하세요."}
license	MIT
metadata	{"author":"https://github.com/Jeffallan","version":"1.1.0","domain":"language","triggers":"SQL optimization, query performance, database design, PostgreSQL, MySQL, SQL Server, window functions, CTEs, query tuning, EXPLAIN plan, database indexing","role":"specialist","scope":"implementation","output-format":"code","related-skills":"devops-engineer"}

SQL Pro

When to Use / When Not to Use

Use when:

• Writing or rewriting SQL queries: joins, CTEs, window functions, recursive queries
• Designing or normalizing a schema
• Interpreting an EXPLAIN plan for a slow query
• Migrating SQL between PostgreSQL, MySQL, and SQL Server dialects

Do not use when:

• The bottleneck is server-level config (use database-optimizer)
• The issue is connection pool exhaustion (use connection-pool-tuner)

Process

1. Schema Analysis — Review table structure, existing indexes, query patterns
2. Design — Draft set-based operations using CTEs, window functions, appropriate joins
3. Version Check — Confirm target engine and version; flag any feature requiring a minimum version
4. Optimize — Analyze execution plans; implement covering indexes; eliminate table scans
5. Verify — Run EXPLAIN ANALYZE and confirm no sequential scans on large tables; iterate until sub-100ms target is met
6. Document — Provide query explanation, index rationale, performance metrics, and minimum version requirements

Output Template

For each SQL task, provide:

1. Optimized query with inline comments
2. Required indexes with rationale
3. Execution plan analysis (key patterns found)
4. Performance metrics (before/after)
5. Platform-specific notes if applicable
6. Minimum version requirements (e.g., PostgreSQL >= 10, MySQL >= 8.0)

What Claude Does / What You Do

Claude	You
Writes set-based query using CTEs or window functions	Provide sample data or schema DDL
Recommends covering index strategy	Run CREATE INDEX CONCURRENTLY in your environment
Reads EXPLAIN output and identifies plan patterns	Provide actual EXPLAIN ANALYZE output
Flags dialect-specific syntax differences	Test against your actual database version
Documents the before/after performance comparison	Validate with production-scale data volumes