HP Integrity NonStop J-Series - Manual (Page 148)

TAILORING AN APPLICATION
Ensuring File Integrity
ENSURING FILE INTEGRITY
Because the starting value of the CHECKDATA attribute is ON, a
basic ENABLE application ensures the integrity of your data base
files by not allowing a user to enter invalid numeric data in
these files. In this case, the term invalid data refers to data
that is of the wrong data type. You can provide one of two
additional methods of ensuring the integrity of your data base
files by supplying values for either the TMF or NONSTOP
attributes.
If a data base file is audited by the Transaction Monitoring
Facility (TMF), you can supply ON as a value for the TMF
attribute when you describe the box that represents this file.
If you supply ON for the TMF attribute, ENABLE includes the
special code required by TMF in the portion of the SCREEN COBOL
requester program that refers to that box.
If a file is not audited by TMF, you can supply ON as a value for
the NONSTOP attribute. When NONSTOP is ON for a box, the copy of
the General Server that is used for the box runs as a NonStop
process pair. This means that a backup copy of the General
Server process is always available to take over if the primary
process fails.
In addition, you can generate an application that accesses both
audited files and nonaudited files. In this case, you must
supply a different copy of the General Server for each group of
files.
Identifying Files Audited by TMF
If an application is to maintain (perform DELETE, INSERT, or
UPDATE operations) a file audited by TMF, the value of the TMF
attribute for that box must be ON. For example, the following
series of commands supplies TMF ON as a value for "employ-box":
SET BOX TMF ON
SET BOX RECORD employee
ADD BOX employ-box
If the purpose of an application is to display information from a
file audited by TMF, you do not have to set TMF ON for the box
that represents this file. In this case, however, you must
supply OFF as the value of the DELETE, INSERT, and UPDATE
attributes.
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