sql-optimization-patterns

Master SQL query optimization, indexing, and EXPLAIN analysis to boost performance and eliminate slow queries.

• Optimize slow SQL queries with execution plans and indexing
• Analyze query performance using EXPLAIN and ANALYZE
• Design efficient database schemas and joins
• Eliminate N+1 queries and optimize pagination

• Use EXPLAIN to analyze query execution plans
• Choose appropriate index types (B-Tree, Hash, GIN, etc.)
• Avoid SELECT *; fetch only needed columns
• Filter data before joins to improve performance
• Use covering indexes to reduce table scans
• Replace OFFSET with cursor-based pagination
• Use index-only scans for efficient COUNTs
• Apply composite and partial indexes strategically

1. 1.Run EXPLAIN or EXPLAIN ANALYZE on queries to inspect performance
2. 2.Create appropriate indexes (e.g., B-Tree, GIN, covering) based on query patterns
3. 3.Rewrite queries to avoid SELECT * and use WHERE filters effectively
4. 4.Replace N+1 queries with JOINs or batch loading
5. 5.Use cursor-based pagination instead of OFFSET for large datasets
6. 6.Filter data early in queries (e.g., before JOINs or COUNTs)