TS/MP Pathsend and Server Programming Manual (H06.05+, J06.03+)

Figure 5 Relationships Between Transaction Functions
Protecting Transactions
After listing and grouping the components of the Enter Sales transaction, you protect the integrity
of each transaction, and ultimately the consistency of the database, with the TMF subsystem. The
pages below outline how to integrate the TMF subsystem with your business transactions. For
information about the overall features of the TMF subsystem, including database file recovery and
audit trails, refer to the Introduction to NonStop Transaction Processing.
Defining TMF Transactions
From a systems perspective, a transaction includes all the steps necessary to transform a database
from one consistent state to another. A TMF transaction must be constructed as a logical unit of
work: that is, all parts of a transaction, which usually consists of multiple operations, must be
handled as a single entity. If any parts of a TMF transaction are not successfully completed or
applied to a database, then none of the transaction parts are applied to the database. By forcing
all components of a transaction to be handled as a single unit of work, the TMF subsystem prevents
inaccurate or partial updates to the database and protects database consistency.
At the application level, a TMF transaction is defined by special procedure calls or statements that
specify the beginning and end of a transaction. For example, in a Pathsend requester program,
a transaction begins with a call to the BEGINTRANSACTION procedure and ends with a call to
the ENDTRANSACTION or ABORTTRANSACTION procedure. The procedure calls that define
32 Designing Your Application