Page 49 - DLIS408_INFORMATION_TECHNOLOGY-APPLICATIONSL SCIENCES

Information Technology and Application

Notes for example, document databases, engineering databases, multimedia databases, or databases
used in the molecular sciences. Various attempts have been made to address this problem, many
of them gathering under banners such as post-relational or NoSQL. Two developments of note are
the Object database and the XML database. The vendors of relational databases have fought off
competition from these newer models by extending the capabilities of their own products to
support a wider variety of data types.

4.3 General-Purpose of DBMS

A DBMS has evolved into a complex software system and its development typically requires
thousands of person-years of development effort. Some general-purpose of DBMSs, like Oracle,
Microsoft SQL server, and IBM DB2, have been in on-going development and enhancement for
thirty years or more. General-purpose of DBMSs aim is to satisfy as many applications as possible,
which typically make them even more complex than special-purpose databases. However, the fact
that they can be used “off the shelf”, as well as their amortized cost over many applications and
instances, make them an attractive alternative (Vs. one-time development) whenever they meet
an application’s requirements.
Though, attractive in many cases, a general-purpose DBMS is not always the optimal solution:
When certain applications are pervasive with many operating instances, each with many users, a
general-purpose DBMS may introduce unnecessary overhead and too large “foot print” (too large
amount of unnecessary, unutilized software code). Such applications usually justify dedicated
development. Typical examples are e-mail systems, though they need to possess certain DBMS
properties: e-mail systems are built in a way that optimizes e-mail messages handling and
managing, and do not need significant portions of a general-purpose DBMS functionality.

People Involved
Three types of people are involved with a general-purpose DBMS:
1. DBMS developers - These are the people that design and build the DBMS product, and the
only ones that touch its code. They are typically the employees of a DBMS vendor
(e.g., Oracle, IBM, Microsoft, or volunteers or supported by interested companies or organi-
zations in the case of Open source DBMSs (e.g., MySQL). They are typically skilled system
programmers. DBMS development is a complicated task, and some of the popular DBMSs
have been under development and enhancement (also to follow progress in technology)
for decades.
2. Application developers and Database administrators - These are the people who design
and build an application which is used in the DBMS. Another group of members design the
needed database and maintain it. The first group members write the needed application
programmes which the application comprises. Both are well familiar with the DBMS prod-
uct and use its user interfaces (as well as usually other tools) for their work. Sometimes the
application itself is packaged and sold as a separate product, which may include the DBMS
inside (subject to proper DBMS licensing), or sold separately as an add-on to the DBMS.
3. Application’s end-users (e.g., accountants, insurance people, medical doctors, etc.) - These people
know the application and its end-user interfaces, but he need not know and to understand the
underlying DBMS. Thus the intended and main beneficiaries of a DBMS, are only indirectly
involved with it.

Task What does DBMS developers do in DBMS?

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