The subject technology receives a query, the query including a set of statements, the set of statements including a first statement comprising a first data manipulation language operation. The subject technology determines that the set of statements includes at least one statement defining a first constraint, and a second statement indicating that the first constraint is statement deferrable for performing validation of the first constraint. The subject technology generates a key value constraint check operator as a node in a query plan. The subject technology generates a key value DML operator as a second node in the query plan, the key value DML operator corresponding to the first DML operation. The subject technology performs, using the key value constraint check operator, a validation process of the first constraint based at least in part on a set of violating keys of each DML operation from the set of statements.