SQL Performance Optimization Guide

🔍 Common Performance Issues

• Slow query execution: Use EXPLAIN to analyze query plans
• High latency: Optimize indexing strategies
• Resource contention: Monitor server load with SHOW PROCESSLIST
• Inefficient joins: Avoid Cartesian products and use proper join types

🛠️ Best Practices

1. Indexing

   • Create indexes on frequently queried columns
   • Use composite indexes wisely
   • Avoid over-indexing to prevent write overhead

2. Query Optimization

   • Limit result sets with LIMIT clauses
   • Avoid SELECT * - specify needed columns
   • Use caching mechanisms for repetitive queries

3. Database Design

   • Normalize tables to reduce redundancy
   • Denormalize strategically for read performance
   • Partition large tables for faster data access

📊 Tools & Techniques

• Use EXPLAIN to visualize query execution plans
• Monitor performance with SHOW ENGINE INNODB STATUS
• Analyze slow queries via slow_query_log
• Optimize with query rewrite tools like SQL Tuning Advisor

🔗 Further Reading

• Database Design Principles
• Advanced SQL Concepts

💡 Pro Tip: Regularly update statistics with ANALYZE TABLE to improve query planner accuracy.