The X/Open DTP Standard
The X/Open DTP standard defines how transaction processing is performed in a distributed, open environment. In this environment, three logical components interact to execute global transactions (logical transactions that may span multiple hardware and software platforms):
• Resource manager
The resource manager (RM) manages access to data (and possibly other shared resources). In an Ingres DTP installation, the resource manager is an Ingres database server acting in combination with Ingres DTP library routines linked into the application.
• Transaction manager
The transaction manager (TM) oversees the execution of global transactions. The transaction manager performs the following functions:
– It accepts global transaction start, commit, and rollback calls from the application program. (Transaction rollback can also be initiated by the transaction manager itself or by the resource manager.)
– It directs resource managers to start, end, prepare, commit, and rollback global transactions. To communicate with resource managers, the transaction manager calls XA routines provided by the resource managers.
• Application program
The application program performs the following functions:
– It interacts with the end-user.
– It notifies the transaction manager when it wants to begin, commit, or abort a transaction. To communicate with the TM, the application program calls routines supplied by the TP vendor.
– It performs database access. To interact with an Ingres database server, the application program uses Ingres embedded SQL.
Last modified date: 04/03/2024