60
4.3.3 Physical Design
Physical model is specific database software, meaning that the objects defined during physical model can vary depending on the relational database software being used.
In this study, Microsoft Access software is used for the relational database. During physical design, object such as tables and columns are created base on the design. Constraints are
also defined including primary keys and foreign keys. More detailed information about
physical design MS Access for each sub system component is shown in Appendix 1.
4.4 Spatial Design
4.4.1 Conceptual Design - ERD
Spatial Entity Relationships Diagrams ERD to express the relationships between
spatial entities of theme are shown in Figure 19. There are some thematic maps, called
layer of maps in the systems, e.g. Industry, River, Monitoring Site, Road, Land Use, Lake, Sub Basin, and Administration Boundary Province, District, Sub District, and Village.
Actually, the other spatial information on layering can be added anytime, while in the shape formats.
61
Figure 19 . Spatial Entity Relationship Diagram
4.4.2 Logical Design Based on entity relationship diagram, the logical model can be derived Table 15.
Table 15 shows that attributes of the entity are only Id and Name, because in the spatial
mode, each entity represents specific information about a certain theme or layer.
Table 15 . Spatial Logical Design
No Entity
Attribute
1 Admin_boundary
Village_Id , Subdis_Id, District_Id,
Province_Id, Village_Name, Shape 2
Industry Industry_Id
, Name, Shape 3
Sub Basin Sub Basin_Id
, Basin_Id, Name, Shape 4
River River_Id
, Name, Shape 5
Monitoring Site MS_Id
, Name, Shape 6
Road Road_Id
, Name, Shape 7
Lake Lake_Id
, Name, Shape 8
Landuse Landuse_Id
, Name, Shape
62
4.4.3. Physical Design
Physical design follows logical design.
Table 16 . Spatial Physical Design
No Entity
Attribute Data type
Width
1 Admin_boundary
Id Varchar
4 Name
Varchar 100
Shape Polygon
2 Industry
Id Varchar
4 Name
Varchar 100
Shape Point
3 Sub Basin
Id Varchar
3 Name
Varchar 100
Shape Polygon
4 River
Id Varchar
5 Name
Varchar 100
Shape Polyline
5 Monitoring Site
Id Varchar
3 Name
Varchar 100
Shape Point
6 Road
Id Varchar
5 Name
Varchar 100
Shape Polyline
7 Lake
Id Varchar
3 Name
Varchar 100
Shape Polygon
8 Landuse
Id Varchar
3 Name
Varchar 10
Shape Line
The GIS software to be used dictates most of the physical database design. The structure and format of the data are in a GIS-ESRI Shape. The translation from the entity
representation in the E-R diagram and logical design to the physical design of the database
ESRI Shape for a single entity is shown in Figure 20.
63
Figure 20 . Physical Model in ESRI Shape Format ESRI
4.5 Data Availability