A deadlock is a special example of a lock conflict. Deadlocks arise when two or more sessions wait for data that has been locked by the other. Because each is waiting for the other, neither can complete their transaction to resolve the conflict.
Oracle Database automatically detects deadlocks and terminates the statement with an error. The proper response to that error is either commit or rollback, which releases any other locks in that session so that the other session can continue its transaction.
