Introduction to ENFORM

Online Transaction Products
Overview of ENFORM
1–6 058051 Tandem Computers Incorporated
Online Transaction
Processing
As illustrated in Figure 1-4, online transaction processing applications typically control
a number of terminals and disk drives that are connected to a host computer on which
the application software runs. The software connects users (through their terminals)
to the database on the disk drives.
The application software consists of transactions that are presented to the system by
operators at the terminals. Transactions are units of work defined by the business that
uses the computer; for example, a change to inventory, the registration of students for
a class, or a request to find out how many wrenches are in stock. A characteristic of
transactions is that they require access to the database—either to search for and
modify information or simply to search for and retrieve information.
Transaction processing then means any system in which transactions are entered by
terminal operators to query or modify a database.
The word online means that the changes made by any transaction are, upon
completion, available to all other terminal operators who access the database. For
example, if a transaction adds a new item to inventory, all succeeding inquiries (after
the transaction completes) about the inventory status will reflect the new item.
Online Transaction
Processing and ENFORM
Typical Tandem online transaction processing applications consist of a mix of
retrieval-only transactions and transactions that both retrieve information and change
it. That is, some transactions modify the data and some only extract data.
PATHWAY and TMF are the products used to build and control the application
transactions that inspect and change the database. ENFORM simplifies the data
retrieval part of the application where the objective of the retrieval is to inquire and
report about information in the database, but not to change the data (Figure 1-5). This
means that application programmers can use ENFORM to reduce the amount of
development time required to produce standard formatted reports. Alternatively,
nonprogrammers can satisfy their information needs without doing any programming
development tasks and without the possibility of accidentally modifying information
in the database.