Conceptual Design - ERD Physical Design

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