The OLE DB Driver for SQL Server implements local transaction support. The consumer can use distributed or coordinated transactions by using Microsoft Distributed Transaction Coordinator (MS DTC). For consumers requiring transaction control that spans multiple sessions, the OLE DB Driver for SQL Server can join transactions initiated and maintained by MS DTC.
By default, the OLE DB Driver for SQL Server uses an autocommit transaction mode, where each discrete action on a consumer session comprises a complete transaction against an instance of SQL Server. The OLE DB Driver for SQL Server autocommit mode is local, and autocommit transactions never span more than a single session.
The OLE DB Driver for SQL Server exposes the ITransactionLocal interface, allowing the consumer to use explicitly and implicitly start transactions on a single connection to an instance of SQL Server. The OLE DB Driver for SQL Server does not support nested local transactions.