Database Server Models for WMS and WFS Geographic Web Services - Geographical Information Systems: Trends and Technologies - page 153

Starting from an extended schema with our new concepts, we proceed
in two phases. The fi rst phase removes attributes that are considered as
irrelevant with respect to a specifi c user's point of view. The second phase
introduces new relevant attributes.
To illustrate these new extensions, we use an example of a conceptual
schema formalized in UML and presented in Fig. 6, as a class diagram. It
describes self-explaining geographical entities: cities, countries, hotels,
restaurants, trees and green spaces. Each class is formalized by a set of
attributes and a set of methods. SR stands for Spatial Representation defi nes
on the OGC Geometry domain. Each method is defi ned as a function (non-
function methods are not visible in the context of this chapter).

G EOGRAPHICAL
O BJECT

With transformation
of schema

F INAL S CHEMA

Ai
.
.
Aj
B1
.
.
Bm

Without transformation
of schema

Injection

I NITIAL S CHEMA

A1
.
.
An

Ai
.
.
Aj

B1
.
.
Bm

.

Determination
of relevant
attributes

Injection

Removal of
irrelevant
attributes

Fig. 5. Enrichment process of data schema.

1..*

Country

City

Location

idCountry : Integer
nameCountry : String
population : Integer
surface : Real
SR : Geometry
GNP : Real

idCity : Integer
nameCity : String
mayor : String
mobileNumberMayor : String
population : Integer
urbanArea : Real
interestPoints[1..*] : Geometry
SR : Geometry
surface(SR : Geometry): Real
percentUrban(SRCity : Geometry, SRUrban : Geometry) : Real
density(population : Integer, surface : Real) : Real

Hotel

idHotel : Integer
nameHotel : String
nameDirector : String
addressHotel : String
park : Geometry
SR : Geometry

1 0..*

Housing

1

1..*

Restaurant

Food

1
0..*

ecology

Tree idRestaurant : Integer

nameRestaurant : String
typeRestaurant : String
addressRestaurant : String
SR : Geometry

0..* 1..*

idTree : Integer
species : String
phytosanitaryStatus : String
plantingYear : Integer
identMarkParcel : Boolean
SR : Geometry

GreenSpace

vegetation

idGreenSpace : Integer
nameGreenSpace : String
maxHeight : Real
typeGreenSpace : String
SR : Geometry
surface ( : Geometry) : Real

Fig. 6. Sample of a conceptual schema.