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 GIS Poject

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… GIS Poject

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 GIS Poject

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 GIS Poject

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 GIS Poject

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 GIS Poject

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 GIS Poject

GDB Design Process GIS Poject

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 GIS Poject

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 GIS Poject

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 GIS Poject

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 GIS Poject

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 GIS Poject

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 GIS Poject

Feature Geometry GIS Poject

Spatial Reference Precision GIS Poject

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 GIS Poject

Precision (<= ArcGIS 9.1) Inverse relationship between spatial extent and precision GIS Poject

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 GIS Poject

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 GIS Poject

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 GIS Poject

Subtype and Validation GIS Poject

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 GIS Poject

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” GIS Poject

Cardinality of Relationships GIS Poject

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 GIS Poject

Example of Relationship Class Pole & Transformers Editing Feature with Composite Relationship GIS Poject

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 GIS Poject

Annotation Types GIS Poject

Summary Real World Representation using Smart Feature GDB Design Consideration GDB Data Structure Subtype and Attribute domain Relationship and Annotation classes GIS Poject

Next… Lab: Spatial Reference and Attribute Domains Lecture: Subtypes and Attribute Domains GIS Poject