log_queries_not_using_indexes

log__slow_admin_statements=1

log_queries_not_using_indexes=ON

log_throttle_queries_not_using_indexes=100

SELECT NULL <> NULL;

SELECT NULL <=> NULL;

SELECT NULL = NULL;

SELECT NULL := NULL;

Option A

Option B

Option C

Option D

ALTER TABLE appointments add index IX_4

ALTER TABLE appointments add index IX_1(credit,payment)

ALTER TABLE appointments add index IX_2(attendant_session_id, created_by)

ALTER TABLE appointments add index IX_3(attendant_id, created_by)

The inserted row is returned because the transaction is auto committed in S2.

The inserted row is not returned because the isolation level is READ COMMITTED in S2.

The inserted row is not returned because the transaction still active in s2.

The inserted row is returned because the isolation level is RPEATABLE READ in S1.

DELIMITER //

CREATE TRIGGER agecheck BEFORE INSERT ON people FOR EACH ROW IF NEW. age < 0 THEN

SET NEW.age =0; END IF;//

DELIMITER ;

ALTER TABLE people ADD COLUMN valid_age=ABS(check_age) GENERATED ALWAYS;

DELIMITER //

CREATE TRIGGER age check AFTER INSERT ON people FOR EACH ROW IF NEW. age < 0 THEN

SET NEW.age =0; END IF;//

DELIMITER;

ALTER TABLE people ADD CONSTRAINT check_age CHECK (ABS(age)>=0);