System.Transactions Namespace

Contains classes that allow you to write your own transactional application and resource manager. Specifically, you can create and participate in a transaction (local or distributed) with one or multiple participants.



Describes a committable transaction.


Describes a clone of a transaction providing guarantee that the transaction cannot be committed until the application comes to rest regarding work on the transaction. This class cannot be inherited.


The permission that is demanded by System.Transactions when management of a transaction is escalated to MSDTC. This class cannot be inherited.


Allows security actions for DistributedTransactionPermission to be applied to code using declarative security. This class cannot be inherited.


Facilitates communication between an enlisted transaction participant and the transaction manager during the final phase of the transaction.


Facilitates communication between an enlisted transaction participant and the transaction manager during the Prepare phase of the transaction.


Provides a set of callbacks that facilitate communication between a participant enlisted for Single Phase Commit and the transaction manager when the SinglePhaseCommit(SinglePhaseEnlistment) notification is received.


Represents a non-rooted transaction that can be delegated. This class cannot be inherited.


Represents a transaction.


The exception that is thrown when an operation is attempted on a transaction that has already been rolled back, or an attempt is made to commit the transaction and the transaction aborts.


Provides data for the following transaction events: DistributedTransactionStarted, TransactionCompleted.


The exception that is thrown when you attempt to do work on a transaction that cannot accept new work.


The exception that is thrown when an operation is attempted on a transaction that is in doubt, or an attempt is made to commit the transaction and the transaction becomes InDoubt.


Provides additional information regarding a transaction.


Facilitates interaction between System.Transactions and components that were previously written to interact with MSDTC, COM+, or System.EnterpriseServices. This class cannot be inherited.


Contains methods used for transaction management. This class cannot be inherited.


The exception that is thrown when a resource manager cannot communicate with the transaction manager.


The exception that is thrown when a promotion fails.


Makes a code block transactional. This class cannot be inherited.



Contains additional information that specifies transaction behaviors.



Describes a DTC transaction.


Describes an interface that a resource manager should implement to provide two phase commit notification callbacks for the transaction manager upon enlisting for participation.


Describes an object that acts as a commit delegate for a non-distributed transaction internal to a resource manager.


Represents a transaction that is not a root transaction, but can be escalated to be managed by the MSDTC.


Describes a resource object that supports single phase commit optimization to participate in a transaction.


Describes a delegated transaction for an existing transaction that can be escalated to be managed by the MSDTC when needed.



Controls what kind of dependent transaction to create.


Determines whether the object should be enlisted during the prepare phase.


Specifies how distributed transactions interact with COM+ transactions.


Specifies the isolation level of a transaction.


Specifies whether transaction flow across thread continuations is enabled for TransactionScope.


Provides additional options for creating a transaction scope.


Describes the current status of a distributed transaction.



Provides a mechanism for the hosting environment to supply its own default notion of Current.


Represents the method that handles the TransactionCompleted event of a Transaction class.


Represents the method that will handle the DistributedTransactionStarted event of a TransactionManager class.


The System.Transactions infrastructure makes transactional programming simple and efficient throughout the platform by supporting transactions initiated in SQL Server, ADO.NET, MSMQ, and the Microsoft Distributed Transaction Coordinator (MSDTC). It provides both an explicit programming model based on the Transaction class, as well as an implicit programming model using the TransactionScope class, in which transactions are automatically managed by the infrastructure. It is highly recommended that you use the easier implicit model for development. To get started, see the Implementing An Implicit Transaction Using Transaction Scope topic. For more information on writing a transactional application, see Writing A Transactional Application.

System.Transactions also provides types for you to implement a resource manager. The transaction manager native to the System.Transactions infrastructure allows volatile resources or a single durable resource enlistment to commit or roll back efficiently. For more information on implementing a resource manager, see Implementing A Resource Manager.

The transaction manager also transparently escalates local transactions to distributed transactions by coordinating through a disk-based transaction manager like the DTC, when an additional durable resource manager enlists itself with a transaction. There are two key ways that the System.Transactions infrastructure provides enhanced performance.

  • Dynamic Escalation, which means that the System.Transactions infrastructure only engages the MSDTC when it is actually required for a transaction. This area is covered in depth in the Transaction Management Escalation topic.

  • Promotable Enlistments, which allows a resource, such as a database, to take ownership of the transaction if it is the only entity participating in the transaction. Later, if needed, the System.Transactions infrastructure can still escalate the management of the transaction to MSDTC. This further reduces the chance of using the MSDTC. This area is covered in depth in the Optimization Using Single Phase Commit and Promotable Single Phase Notification topic.

For more information on how to use the System.Transactions namespace, see Transaction Processing.