DATABASE DEVELOPMENT LIFE CYCLE - Database Design and Development: An Essential Guide for IT Professionals - page 109

Technological Infrastructure
Business analysts first look at the technological infrastructure to assess its adequacy
for the proposed database system. Technological infrastructure includes both hard-
ware and systems software. This is the platform on which the database system will
operate. Business analysts size up the proposed data volumes and the estimated
number of transactions to study whether the available infrastructure can support
the database system. The technological feasibility study involves taking an inven-
tory of existing hardware and systems software; the study usually results in recom-
mendations for additional hardware and upgrades of the systems software.
Hardware Consider the hardware environment for the proposed database system.
The database will usually reside on a database server machine. Database manage-
ment system (DBMS) software will run on the server machine. How big and pow-
erful the server machine has to be depends on the size and use of the database. If
the data content were large, you would need ample storage and a choice of better
media for storing the data. If rapid data access were critical, you would need faster
storage media. In a database environment where information is shared, keeping the
database available at all times becomes crucial. Therefore, storing data in fault-
tolerant storage media is desirable. Most database systems use RAID (redundant
array of inexpensive disks) storage technology. This technology provides duplicate
versions to be stored with mirroring techniques. We will focus more on this tech-
nology later, but for now just note that many aspects and options must be consid-
ered for database storage.
What about the applications for the users to draw on the wealth of data stored in
the proposed database? Applications in a database environment tend to be more
sophisticated than those in a file-oriented environment. Database applications mul-
tiply quickly. Because these applications are more standardized and uniform, their
spread to many user groups becomes easier. Where should the applications run? On
the client machines? If the proposed applications in your organization are expected
to be more involved, large, and widespread, the business analysts doing the feasibil-
ity study may consider running the applications in the middle tier on separate appli-
cation servers. This option will also make deployment of the applications easier.
Now turn your attention to client machines. How many additional client
machines does your organization need? What about the speed and capacity of each
machine? The business analysts need to take an inventory of the client machines in
each user department and assess the number and types of additional machines
required.
Study of the hardware configuration also includes review of the communication
network links. This is very important if the user groups are spread out in multiple
geographic regions domestically or internationally. Will the network configuration
be adequate to deliver data from the proposed database? What about the public
carriers? What about the sufficiency of the bandwidth? Will the Internet be a deliv-
ery medium in your database environment? These are some of the major questions
the business analysts must consider.
Systems Software Database management system software (DBMS) interacts
with the operating system for accessing data from the database. Every query or