Implemented ACID (atomicity, consistency, isolation, durability) transactions. Instant rollback. The transactions are executing on a single table (single transaction) or table set (complex transaction) level. There are no practical limits over the size or the complexity of the transaction.
- Atomicity requires that database modifications must follow an all or nothing rule. Each transaction is said to be atomic if when one part of the transaction fails, the entire transaction fails and database state is left unchanged.
- The consistency property ensures that the database remains in a consistent state; more precisely, it says that any transaction will take the database from one consistent state to another consistent state.
- Isolation refers to the requirement that other operations cannot access or see data that has been modified during a transaction that has not yet completed. Each transaction must remain unaware of other concurrently executing transactions, except that one transaction may be forced to wait for the completion of another transaction that has modified data that the waiting transaction requires.
- Durability is the DBMS's guarantee that once the user has been notified of a transaction's success, the transaction will not be lost. Durability does not imply a permanent state of the database. A subsequent transaction may modify data changed by a prior transaction without violating the durability principle.
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