Database Reference
In-Depth Information
As with entity naming, you should be as conscious as possible of the
fact that nontechnical personnel will read through this design at least once.
Attribute names should be concise and unambiguous. And as with entity
naming, it's good to use mixed-case attribute names unless there is a spe-
cific reason not to.
Notations Standards
Naming conventions used in your data model are based strictly on your
personal preference, or at least your professional preference, but there are
industry-standard specifications that outline how a data model should be
notated, or described. Although there is plenty of history surrounding the
various notation methods, we cover the notation method that is most pop-
ular and offer a basic history of where it came from and why to use it. So
get out your notebooks, spit out your gum, and pay attention. There will be
a quiz later.
IDEF
In the mid-1970s, the U.S. Air Force was in the midst of an initiative to de-
fine and update its computing infrastructure, specifically as related to man-
ufacturing. As part of that project, an initiative was launched called
Integrated Computer-Aided Manufacturing, or ICAM. Dennis E.
Wisnosky and Dan L. Shunk, who were running the project, eventually
concluded that manufacturing was in fact an integrated process, with sev-
eral components describing the whole. They needed to develop tools,
processes, and techniques to deal with all the various components; in ad-
dition, they understood inherently the data-centric nature of manufactur-
ing and the need to analyze and document which data existed and how it
moved from system to system.
Eventually, the two men created a standard for modeling data and
showing how it relates to itself and other systems, as well as modeling
process and business flow. These standards were initially known as the
ICAM definitions, or IDEFs. To this day, ICAM continues to refine and
define new standards based on the original IDEF, with an eye toward con-
tinuing to improve information technology and understanding how it re-
lates to real-world systems.
Here are the most commonly used IDEFs:
IDEF0: Function modeling
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IDEF1: Information modeling
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