1. Physical Structure of GDB
Geodatabase
Feature datasets
Spatial Reference
Object classes, subtypes
Features classes, subtypes
Raster datasets
Rasters
Relationship classes
Geometric networks
TIN datasets
nodes, edges, faces
Planar topologies
Locators
Domains
Addresses, X.Y location
ZIP Codes, Place names
Validation rules
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2. Smart Features Real World Representation (5)
Geography,
KHU,
Jinmu Choi
Real World Representation (5)
Shapes, Attributes, Domains, Relationships, and Behaviors
GDB Design Consideration (6)
GDB Data Structure (6)
Table, Geometry, Spatial Reference, Extend, Precision, and Attribute
Subtype and Attribute Domain (3)
Relationship and Annotation Classes (7)
Summary, Review, and Next…
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3. Shapes & Spatial Reference
Stored as a special field (geometry) in a feature class table
Types
Points and multipoints: a set of points
Polylines: a set of line segments
Polygons: a set of rings
Spatial reference
How x,y coordinates of a set of features are mapped onto the earth’s surface
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4. Attributes and Subtypes
Fields in a class table
Properties of features
Subtypes
Building subtype: residential, commercial, and industrial
Subtypes give you a more control over other qualities such as attribute domains and rules
lightweight classification
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5. Domain and Rule (Attribute) Domain Rules
A numeric range or a list of valid values
Distinct attribute domain and default value for each subtype
Rules
To constrain how the parts of a network are connected
The cardinality of relationships for feature validation
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6. Relationship and Topology
Define explicit relationships among features in different feature classes
Define non-spatial relationships
2-D Planner topology: area
Land parcels must adjoin each other without gaps or overlaps
1-D network topology: line
The lines and devices of a utility network must be continuously and unambiguously connected
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7. Behavior Simple behaviors Complex behaviors
Choosing a feature type and topological association
Setting up relationships
Assigning attribute domains
Specifying validation rules
Complex behaviors
Writing software code for a custom feature
Implemented behaviors
Custom editing interaction
Intrinsic analytical capabilities
Sophisticated cartographic rendering
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8. GDB Design Process
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9. Why One GDB
Reasons to group a set of features into a common geodatabase
A set of features and objects have relationships
Features that have a topological associations
Editing one GDB at a time:
Concurrently edit a set of features
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10. Why Separate GDB Reasons to separate a set of features
When works in large and separate departments
When use of multiple commercial relational databases
Size limitation of personal geodatabase
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11. Why Feature Datasets
Reasons to group feature classes into a feature dataset
Topologically related classes should be reside in a common feature dataset
To enforce a common spatial reference for a set of feature classes
To group thematically related classes
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12. Why Subtypes Reason to use subtypes
A lightweight classification of features (or object) within a feature (or object) class
For performance, reduce the number of feature classes
To control specific behaviors for a set of features in a feature class
Attribute rules, default values, connectivity rules, and relationship rules
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13. Why Separate Classes
Reasons to use different classes instead of subtypes
A group of features need distinct custom behavior
The set of attributes are different
Need different access privileges
Some features are accessed through versions, the others not
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14. Table: data storage Table is organized into rows and columns Types
Row: a set of properties of an object
Column: same type of attribute of all objects
Types
A table stores nonspatial object: object class
A table stores spatial object: feature class
A table stores relationship: relationship class
Field (column) types
Value: coded value, text, real number, counted value, unique ID
Predefined field: Unique ID, geometry types
Custom field: users can modify
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15. Feature Geometry
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16. Spatial Reference
Precision
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17. Spatial Extent
Spatial extent: the allowable range for x and y coordinates
Defined during feature class creation
Imported from other geodatabase
Imported from a shapefile: 10 times larger
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18. Precision (<= ArcGIS 9.1)
Inverse relationship between spatial extent and precision
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19. Attribute Continuous numeric values with floats and doubles
Discrete numeric values with shorts and integers
Coded values with shorts, integers, and texts
Description with text
Time values with dates
Object ID
Multimedia with BLOBs
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20. Subtypes A special attribute Lightweight subdivision:
To assign distinct simple behavior for different classifications of your objects or features
Lightweight subdivision:
To describe each member of a classification
To define distinct attribute domains
To define distinct default values
To prescribe the types of relationships that are possible between the objects in different subtypes
With codes, add custom rules for subtypes
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21. Attribute Domains and Rules
Attribute domains: constraints on attributes
Range domain for numeric values: constraints on min and max values
Coded value domain for type values: only used one of the defined list of values
Validation rules: control feature integrity
Attribute Rule: attribute domain is a constraint of attribute values
Connectivity rule: the valid pairs of attribute values for subtypes for connected network features
edge-junction, edge-edge…
Relationship rule: the cardinality of a relationship between subtypes in classes
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22. Subtype and Validation
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23. Relationships
Objects in the world have relationships with other objects
Relationship types
Topological R. to answer what is connected or adjacent
Spatial R. to answer what is spatial related, touches, coincides with, overlap, in(out)side
General R. is explicitly defined relationship between objects or features in different classes
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24. Relationship Class Relationship is an association between two objects
Relationships in a relationship class have the same origin class and destination class
Referential integrity between objects during editing an object in the classes
Path labels: a direction of relationship
Forward path label: “manage”
Backward path label: “managed by”
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25. Cardinality of Relationships
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26. Attributed Relationship Class
One-to-one or one-to-many cardinality
Foreign key connects origin and destination tables
No need to build relationship table
Many-to-many cardinality
Relationship table is required
Foreign key cannot record all the relationship
Relationship table has a relationship in each row
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27. Example of Relationship Class
Pole & Transformers
Editing Feature with Composite Relationship
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28. Annotation Class
Annotation is a type of feature that provides a textual description
Annotation class is a feature class that contains annotation
Feature-linked annotation
Closely bound to a feature by a composite relationship between a feature class and annotation class
Simple annotation
Annotation that is not linked to a feature
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29. Annotation Types
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30. Summary Real World Representation using Smart Feature
GDB Design Consideration
GDB Data Structure
Subtype and Attribute domain
Relationship and Annotation classes
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31. Next… Lab: Spatial Reference and Attribute Domains
Lecture: Subtypes and Attribute Domains
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