DROP TABLE IF EXISTS users;
CREATE TABLE users (
id INT,
age INT,
INDEX (age)
) DEFAULT CHARSET=UTF8MB4;
INSERT INTO users (id, age) VALUES (1, 29);
INSERT INTO users (id, age) VALUES (2, 29);
INSERT INTO users (id, age) VALUES (3, 29);
SELECT COUNT(*) FROM users WHERE id = 3 AND age = 29;
COUNT(*)
1
SHOW STATUS LIKE 'mroonga_count_skip';
Variable_name	Value
Mroonga_count_skip	0
DROP TABLE users;
