Interview Question

What is query optimization?

Query optimization chooses a plan; tuning supplies better structure and evidence.

💡 Concept ✅ Quick Revision 🗃️ SQL

Answer

Query optimization is the process of choosing an efficient execution plan for a SQL statement. • The optimizer compares possible scans, joins, and operation orders. • Statistics help estimate row counts and costs. • Developers improve results with correct queries, useful indexes, current statistics, and measurement.

💡 SQL Example

EXPLAIN ANALYZE SELECT * FROM orders WHERE customer_id = 10;

Result

The actual and estimated execution plan

⚡ Quick Revision

Query optimization chooses a plan; tuning supplies better structure and evidence.