Introduction to Data Management

Ensuring Database Consistency With TMF
7-12 15873 Tandem Computers Incorporated
Developing an
Application with TMF
To develop an application for the PATHWAY environment, you typically employ
TMF in the following steps:
1. Design your application so that it includes a series of discretely identifiable
transactions against your database.
2. Code your application, using SCREEN COBOL for your requesters and another
appropriate language for your servers.
3. In your SCREEN COBOL programs, identify the boundaries of each transaction
with the approriate BEGIN-TRANSACTION and END-TRANSACTION
statements. Also, use other statements to request additional TMF operations as
needed.
4. Configure your application under PATHWAY, and test the application.
Managing a System
Using TMF
To manage a system where applications rely on TMF, you perform the following
major tasks:
Determine and specify those files in the database that must be audited by TMF.
Configure TMF and specify required audit trail characteristics, using the
interactive TMFCOM utility, the File Utility Program (FUP), and the Peripheral
Utility Program (PUP). The audit trail characteristics include the number of audit
trails needed, the amount of disk space allocated to them, and their location; you
also specify a sequence of files that TMF is to create as it builds its audit trails.
Periodically reply to TMF audit trail dump requests by mounting the appropriate
magnetic tape. TMF automatically backs up and removes old audit trails before
disk space is filled.
Periodically request online dumps to back up your database, allowing for recovery
from catastrophic failures.
Perform TMF control operations such as starting and stopping TMF activity,
requesting status of specific transactions, and changing attributes for audit-dump
processes, through the use of TMFCOM.
Start the rollforward process after a disk crash or a total system failure.