FREE online courses on Information Technology - Chapter 9 INFORMATION
TECHNOLOGY ARCHITECTURES - Mainframes for High Volume
The mainframe is the traditional machine for developing
applications. Today, mainframes are used for very high volume transactions
processing. American Express authorizes purchases for holders of
American Express card when a merchant calls to determine if AMERICAN express
will agree to
the charge This high volume application to access credit records and decide on approving
the charge resides on mainframe computers.
Mainframes are also associated with extremely large databases
.It not unusual for organizations like banks and insurance companies to have
data files that contain many
billions of characters gigabytes .
These firms have entire rooms for organizations like banks and insurance
companies to have data files that contain many billions of characters gigabytes
These firms have entire rooms filled with disk drives containing important data
that aye online for inquiry and updating.
Mainframe applications typically feature a large number of
users of the data. These machine are designed to manage huge communications networks in which users using remote
terminals access the mainframe and its databases. However, what the user can do
is fairly limited. Typically, certain functions are made available to each user.
Although it is theoretically possible, most mainframe systems do not provide
extensive data manipulation features to users.
Thus, the user's discretion is often limited. However, in
transactions processing applications, designers usually do not want the user to
have more than limited capabilities. It is not a good idea for a reservation
agent to analyze flight data; the job should be done by the marketing or
operations department of the airline. The transactions processing system is an
operational system, not a system for analysis and reflection.
