Transaction Manager

A distributed transaction is a transaction that accesses and updates data on two or more networked resources. These resources could consist of several different RDBMSs housed on a single sever, for example, Oracle, SQL Server, and Sybase; or they could include several instances of a single type of database residing on a number of different servers. In any case, a distributed transaction involves coordination among the various resource managers. This coordination is the function of the transaction manager.

The transaction manager is responsible for making the final decision either to commit or rollback any distributed transaction. A commit decision should lead to a successful transaction; rollback leaves the data in the database unaltered. JTA specifies standard Java interfaces between the transaction manager and the other components in a distributed transaction: the application, the application server, and the resource managers.

Most enterprises use transaction managers and application servers because they manage distributed transactions much more efficiently than an application can.