domains / data / sql-optimization / sql-pro

sql-pro

Skill card

combined

The copies overlap on the core task of SQL optimization and query tuning, but they disagree on scope and procedure. Jeffallan/claude-skills provides a concrete, actionable workflow (Schema Analysis -> Design -> Optimize -> Verify -> Document) with specific constraints (e.g., sub-100ms target, covering indexes, set-based operations) and reference files. The other two copies (rmyndharis and sickn33) are nearly identical, broad persona definitions that list extensive capabilities (cloud-native, HTAP, security, DevOps) but lack the specific procedural steps and verification targets found in the Jeffallan copy. Crowning one would hide the alternative approach of broad capability definition vs. specific procedural execution.

Repositories

Other copies

Combined skill

---
name: sql-pro
description: Optimizes SQL queries, designs database schemas, and troubleshoots performance issues. Use for complex queries, window functions, CTEs, indexing strategies, query plan analysis, and database dialect migration.
---

# SQL Pro

## Core Workflow

1. **Define Goals & Schema Analysis** - Review database structure, indexes, query patterns, and performance bottlenecks. Define query goals, constraints, and expected outputs.
2. **Design** - Create set-based operations using CTEs, window functions, and appropriate joins. Consider cloud-native and hybrid OLTP/OLAP patterns if applicable.
3. **Optimize** - Analyze execution plans, implement covering indexes, and eliminate table scans. Apply filtering early in query execution.
4. **Verify** - Run `EXPLAIN ANALYZE` and confirm no sequential scans on large tables. If the query does not meet the sub-100ms target (or specific workload target), iterate on index selection or query rewrite. Verify correctness and performance under load.
5. **Document** - Provide query explanations, index rationale, and performance metrics (before/after).

## Constraints

### MUST DO
- Analyze execution plans before recommending optimizations.
- Use set-based operations over row-by-row processing.
- Apply filtering early in query execution (before joins where possible).
- Use EXISTS over COUNT for existence checks.
- Handle NULLs explicitly in comparisons and aggregations.
- Create covering indexes for frequent queries.
- Test with production-scale data volumes.
- Use read replicas or limits for exploratory analysis on production systems.

### MUST NOT DO
- Use SELECT * in production queries.
- Use cursors when set-based operations work.
- Ignore platform-specific optimizations when targeting a specific dialect.
- Implement solutions without considering data volume and cardinality.
- Run heavy queries on production without safeguards.

## Output Templates

When implementing SQL solutions, provide:
1. Optimized query with inline comments.
2. Required indexes with rationale.
3. Execution plan analysis.
4. Performance metrics (before/after).
5. Platform-specific notes if applicable.

## Conflicts

- **Jeffallan/claude-skills** specifies a sub-100ms target and a 5-step workflow including a 'Document' phase.
- **rmyndharis/antigravity-skills** and **sickn33/agentic-awesome-skills** specify a 4-step workflow without a specific latency target and focus on a broader range of capabilities (cloud, security, DevOps) rather than a strict procedural checklist.