# Query Optimization

> SQL query optimization and performance tuning

- Skill: `pluginagentmarketplace-custom-plugin-sql/query-optimization` (Agent Skill, multi-file: 6 files)
- Install (CLI): `npx skillmds add pluginagentmarketplace-custom-plugin-sql/query-optimization`
- Raw SKILL.md: https://api.skillmd.com/api/skills/pluginagentmarketplace-custom-plugin-sql/query-optimization/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Data & Analytics
- Author: pluginagentmarketplace (https://skillmd.com/u/pluginagentmarketplace-custom-plugin-sql)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/pluginagentmarketplace-custom-plugin-sql/query-optimization

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# Query Optimization Skill

## Overview
Optimize SQL queries for maximum performance across different database systems.

## Topics Covered

### Query Analysis
- EXPLAIN plans
- Execution statistics
- Cost-based optimization
- Query profiling
- Wait event analysis

### Indexing Strategy
- B-tree indexes
- Covering indexes
- Partial indexes
- Index selection
- Index maintenance

### Query Patterns
- JOIN optimization
- Subquery alternatives
- Aggregate optimization
- Pagination patterns
- Bulk operations

### Database Specific
- PostgreSQL optimization
- MySQL tuning
- SQL Server hints
- Oracle optimization
- Cloud DB optimization

## Prerequisites
- SQL fundamentals
- Database internals basics

## Learning Outcomes
- Analyze query plans
- Create effective indexes
- Rewrite slow queries
- Tune database performance