EXPLAIN

An EXPLAIN is not actually a statement, but rather a string prefix that can be placed before most SQL statements that will cause the query planner to return the strategy for executing the query without actually running it. This is useful for debugging query performance.

Contents

• EXPLAIN

  • Syntax

  • Examples

Syntax

EXPLAIN ...

Examples

EXPLAIN SELECT * FROM products
WHERE product_id >= 123 AND product_id <= 456
OFFSET 3 ROWS FETCH FIRST 2 ROWS ONLY;

-- TABLE PRODUCTS OFFSET 3 ROWS
-- WHERE PRODUCT_ID >= 123 AND PRODUCT_ID <= 456
-- FETCH FIRST 2 ROWS ONLY

EXPLAIN DELETE FROM products
WHERE product_id = 100;

-- TABLE PRODUCTS
-- WHERE PRODUCT_ID = 100

EXPLAIN UPDATE products SET price = price * 1.1;

-- TABLE PRODUCTS