Query Optimization Tips
6 min read
Optimize by indexing WHERE and JOIN columns, avoiding functions on indexed columns, and using EXPLAIN ANALYZE to verify plans. Set shared_buffers to 25% of RAM. Always identify real bottlenecks before optimizing.
Top Optimization Tips
- Use
EXPLAIN ANALYZE before tuning - Add indexes on columns in WHERE, JOIN, ORDER BY
- Avoid
SELECT * — only fetch needed columns - Use
LIMIT when you don't need all rows - Use
EXISTS instead of COUNT() > 0 - Prefer
JOIN over correlated subqueries - Partition large tables (>50M rows)
- Use materialized views for heavy dashboards