No matter how much time is allowed to pass, this situation will never resolve itself and because of this database management systems will typically kill the transaction of the process that has done the least amount of work. Process A can't finish updating row 2 until process B is finished, but it cannot finish updating row 1 until process A finishes. For example, process A updates row 1 then row 2 in the exact timeframe process B updates row 2 then row 1.
In a transactional database, a deadlock happens when two processes each within its own transaction updates two rows of information but in the opposite order. Deadlock A deadlock is a situation in which two or more competing actions are each waiting for the other to finish, and thus neither ever does.
