Database Reference
In-Depth Information
Figure 5-15.
Attributes for the Mountaineering Problem
How may we obtain an appropriate conceptual schema for the mountaineering
problem? We may approach this problem in one of two ways:
•
The Pragmatic Approach
: Identify related attributes that form data
entities, normalize these entities, then identify and rationalize
relationships among the entities.
•
The Classical (theoretical) Approach
: Start out by creating
one large 1NF relation involving all attributes, progressively
decompose into relations of higher normal forms until the given
requirements are met.
In the interest of illustrating application of the theory of normalization, we shall
pursue the second approach. However, please bear in mind that in most real life
situations, you will be advised to employ the pragmatic approach. Several of the cases in
chapter 26 (for instance, assignments 1 and 2) provide an excellent opportunity for you to
do this.
Step 1 — Create a large 1NF Relation
We introduce three new attributes:
Climber Identification
[CID#],
Mountain
Identification
[MTN#], and
Country Code
[CTRYCD]; store all attributes as relation
M
as
shown in Figure
5-16
. The figure also states the observed functional dependencies.
