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DECdtm/XA SDK for Alpha
To
ensure the integrity, atomicity, and consistency of distributed
transactions, use DECdtm System Services, which are available
on OpenVMS.
DECdtm is a distributed transaction manager that coordinates the
activity of resource managers used by an application. For example,
DECdtm can coordinate the actions of resource managers such as
Rdb, Oracle, DBMS, or OpenVMS RMS Journaling. DECdtm implements
a two-phase commit protocol to achieve all-or-nothing data integrity
(either all operations in a transaction are completed or none
of them). If all operations in a transaction are completed, the
transaction is said to be committed; if none of them are completed,
the transaction is aborted.
The
case of an employee transfer illustrates these concepts.
Edward
Jessup, employed by a company in Italy, is transferring to a subsidiary
in Japan. The application that holds his personnel information
must delete this information from its Oracle database in Italy
and add it to its Rdb database in Japan. Both of these operations
must be complete or the data about this employee will be "lost
in cyberspace." With DECdtm, such an error will not happen.
The
DECdtm services are embedded in the OpenVMS operating system.
No separate license is required.
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