Deadlocks can adversely influence server performance. A deadlock occurs when two or more SQL Server processes each have locks on distinct database objects. While holding on to their existing locks, each process is trying to acquire a lock on the database object that one of the other processes have locked. Because two processes cannot exclusively lock the same object simultaneously, we get a deadlock situation, where both processes are entangled and neither process is able to move forward. SQL Server recognizes this situation and tries to rectify it by killing one of the processes in order to allow the other process to continue. The terminated process is rolled back and then an error is flagged.