Database Indexing Strategies: Optimizing Query Performance

# Database Indexing Strategies: Optimizing Query Performance Proper indexing is crucial for database performance. This guide covers indexing strategies for PostgreSQL and other relational databases. ## Index Types ### B-Tree Indexes (Default) Most common index type, good for equality and range queries: ```sql CREATE INDEX idx_user_email ON users(email); CREATE INDEX idx_order_date ON orders(created_at); ``` ### Composite Indexes Index multiple columns together: ```sql CREATE INDEX idx_user_status_email ON users(status, email); -- Efficient for queries like: SELECT * FROM users WHERE status = 'active' AND email = 'user@example.com'; ``` ### Partial Indexes Index subset of rows: ```sql CREATE INDEX idx_active_users ON users(email) WHERE status = 'active'; ``` ## Index Design Principles 1. Index frequently queried columns 2. Index foreign keys 3. Consider composite indexes for multi-column queries 4. Use partial indexes for filtered queries 5. Monitor index usage and remove unused indexes ## Query Analysis ```sql EXPLAIN ANALYZE SELECT * FROM users WHERE email = 'user@example.com'; ``` ## Conclusion Effective indexing dramatically improves query performance. Analyze your queries and create appropriate indexes.