<P> Upon being ended (completed), a transaction's allocated computing resources are released and the transaction disappears from the computing environment . However, the effects of a committed transaction remain in the database, while the effects of an aborted (rolled - back) transaction disappear from the database . The concept of atomic transaction ("all or nothing" semantics) was designed to exactly achieve this behavior, in order to control correctness in complex faulty systems . </P> <P> Serializability is used to keep the data in the data item in a consistent state . Serializability is a property of a transaction schedule (history). It relates to the isolation property of a database transaction . </P> <Dl> <Dd> Serializability of a schedule means equivalence (in the outcome, the database state, data values) to a serial schedule (i.e., sequential with no transaction overlap in time) with the same transactions . It is the major criterion for the correctness of concurrent transactions' schedule, and thus supported in all general purpose database systems </Dd> </Dl> <Dd> Serializability of a schedule means equivalence (in the outcome, the database state, data values) to a serial schedule (i.e., sequential with no transaction overlap in time) with the same transactions . It is the major criterion for the correctness of concurrent transactions' schedule, and thus supported in all general purpose database systems </Dd>

There can exist view serializable schedule which is not conflict serializable