TMF Glossary (H06.03+)

TMF Glossary
HP NonStop TMF Glossary—540135-001
Glossary-18
transaction
transaction. An operation or a series of operations that transforms a database from one
consistent state to another. TMF treats transactions as a single unit; either all of the
changes made by a transaction are made permanent (the transaction is committed) or
none of the changes are made permanent (the transaction is aborted). If an error
occurs while a transaction is in progress, TMF backs out whatever partial changes
were made to the database, leaving it in a consistent state. In application programs,
transactions are begun by using BEGINTRANSACTION statements, ended by using
ENDTRANSACTION statements, and aborted by using ABORTTRANSACTION
statements.
transaction backout. See backout.
transaction control records. A type of audit trail record that identifies transaction-related
events such as transaction committed, transaction aborted, and undo incomplete.
Together with before-images and after-images, these records constitute a
chronological record of all transaction-related activities.
transaction identifier (TransID). A unique name that TMF assigns to a transaction.
Transaction Management Facility (TMF). See TMF.
transaction management process (TMP). The TMF management process pair, always
named $TMP, coordinates transactions distributed over a network. The TMP is also in
charge of operations that require a single point of control in a server, such as starting
and stopping TMF, initiating recovery processes, and implementing configuration
changes. The TMP manages the data volumes and audit trails and is the final
authority on whether transactions are committed or aborted; it also creates other TMF
processes as needed.
transaction mode. The operating mode of a terminal program between the execution of a
BEGINTRANSACTION statement and the execution of the associated
ENDTRANSACTION or ABORTTRANSACTION statement.
transaction pseudofile (TFILE). A construct used by TMF to provide access control block
(ACB) space for transaction control and state information. The TFILE does not reside
on a physical I/O device.
two-phase commit. An industry-standard series of operations performed when an
ENDTRANSACTION statement is executed to commit a transaction. In the first phase,
the before-images and after-images for the transaction are written to the audit trail on
disk. In the second phase, locks held by the transaction are released.