Interview Question

What is execution plan?

An execution plan shows how the database intends to execute a query.

💡 Concept ✅ Quick Revision 🗃️ SQL

Answer

An execution plan describes the operations the database chooses to run a query. • Plan nodes can include scans, joins, sorts, and aggregates. • Estimated costs and row counts help explain optimizer decisions. • EXPLAIN ANALYZE executes the statement, so use it carefully with data-changing statements.

💡 SQL Example

EXPLAIN SELECT * FROM employees WHERE department_id = 10;

Result

A tree of planned database operations

⚡ Quick Revision

An execution plan shows how the database intends to execute a query.