First, four characteristics are:.... 1 atomicity, consistency 2, 3 Isolation, persistence 4
1. Atomic: A transaction includes all operations either all succeed, or all fail rollback; success must be fully used in the database, the failure can not have an impact on the database.
2. Consistency: before transaction execution and implementation and must be in a consistent state
3. Isolation: when a plurality of users concurrent access to the database, a database open transactions for each user, the operation is not disturbed by other transactions, for isolation between a plurality of concurrent transactions
4. Durability: Once a transaction is committed, then changes to the data in the database is permanent, even when the database system experienced a failure of the operation will not be lost things.