Transactions guarantee integrity of the data. Transactions are usually associated with updates to multiple tables or multiple data stores. Transactional behavior is assigned to each COM component, and transactional behavior can be set to NoTransactions when it is clear that there is no possibility of corrupting data. When a new object is created, its object context is created without a transaction. See Designing the CML Components and Objects for further discussion of transactional behavior of CML application class modules.
Two-phase commit ensures that transactions on multiple servers are completed on all servers or not at all. MTS uses the services of Microsoft Distributed Transaction Coordinator (MS DTC) to coordinate transactions that span resource managers. The transaction fails or succeeds as a whole.