Using the Geodatabase

Transcription

1 Using the Geodatabase February 13, 2002 Presented by: John Stroud, ESRI

2 GeoDatabase Geodatabase comes in two flavors Personal mdb format ArcSDE rdbms format ArcGIS is a suite of three products ArcView, ArcEditor, ArcInfo Choice of product impacts functionality with geodatabase ArcEditor, ArcInfo allow for more geodatabase functionality

3 The Geodatabase, what is it? A more advanced ESRI data model that works in the ArcGIS application environment. Stored in Access or other RDBMS via ArcSDE

4 Geodatabase basics Stores tables, feature classes, feature datasets, more Tables A collection of attribute rows and columns Feature classes A collection of features feature dataset Conceptually like a shapefile feature classes Feature datasets A collection of feature classes table Conceptually like a coverage Rules / relationships Attribute and spatial

5 Creating geodatabases,, feature classes, or tables Primarily performed in ArcCatalog 1 2

6 Creating new feature classes Like creating tables, but has a Geometry field Set Geometry Type Set Spatial Reference (if not in feature dataset) Geomtery Type Properties for the shape field Spatial Reference 3

7 Setting the spatial reference For feature datasets or feature classes Set Coordinate System Set X/Y domain Set Z domain Set M domain Import from existing feature dataset or coverage A

8 Coordinate Domains X, Y coordinates are stored as Long Integers (range of 2.14 billion) Lost Data 2.40 mil, 0.80 mil Default Domain Tundra County Larger area, smaller Precision (1,000) 21000, mil, 0.65 mil Small total area, large precision (100,000) 0, 0

9 Creating feature datasets Organizes feature classes (optional) Have spatial reference (feature classes inherit) Select the geodatabase Name the Feature Dataset Set the spatial reference Select New > Feature Dataset 1 2

10 Importing and exporting feature In ArcCatalog or ArcToolbox Same tools, wizards Coverages, shapefiles, tables, etc classes

11 Load features into existing feature class In ArcCatalog or ArcMap From multiple data sources at once Rematch attributes All features or only features based on an expression

12 Coded value domains in ArcMap Attributes editor only shows valid values The description is displayed instead of the code

13 Range domains in ArcMap Use the Validate Selection command to see if any values are outside the range Invalid features remain selected LINE_SIZE has a range domain of 10 16

14 Edit multiple data sets simultaneously Snap to features across data sets Add vertexes based on Distance, Angle, Intersection, and Multiple Distances Validate attributes using attribute domains Coded values domains and range domains Shared Edge Editing Feature Editing

15 Storing the geodatabase Personal geodatabase Stored in an MDB file ArcSDE geodatabase Stored in an RDBMS Connect through ArcSDE server or direct Need ArcEditor or ArcInfo license to edit The difference Personal GDB size limit 2GB Only ArcSDE GDB allows multi-user editing Only ArcSDE stores raster data No Connect Personal geodatabase ArcGIS ArcSDE Connect ArcSDE Direct Connect Multi-user Geodatabase A

16 Why use an RDBMS Data maintenance Standardized access Multi-user access Data protection Recovery Security

17 Before you create your geodatabase One of the most important steps in creating an effective database is designing its schema. The same is true for any geodatabase. When designing a geodatabase, you should consider questions such as: What kind of data will be stored in the database? In what projection do you want your data stored? Do you want to establish rules about how the data can be modified? In what object classes would you like to organize your information? Do you want to use subtypes? (ArcInfo and ArcEditor only) Do you want to maintain special relationships between objects of different types? (ArcInfo and ArcEditor only) Will your database contain a network? (ArcInfo and ArcEditor only) Will your database store custom objects? (ArcInfo and ArcEditor only)

18 Advanced feature functionality ArcEditor / ArcInfo More sophisticated database, less required coding Relationship classes (simple or composite) Feature linked annotation Dynamic geocoding Dimension feature classes Subtypes Geometric networks Connectivity rules

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20 Tips If you are working with ArcView 8.1, review ArcView 8.1 and the geodatabase to learn more about the functionality available with ArcView before deciding which items to include in your database design. Try to do all your data loading before versioning your data. Try to load all your data before building geometric networks. Minimize the number of network feature classes If you load lots of data into a versioned geodatabase, run Compress to reduce the size of the delta tables. Avoid storing non-coincident data in a feature dataset Integrate works on all feature classes in a feature dataset Don t store too many feature classes in a dataset May impact performance Test design to determine performance thresholds

21 Demo: Creating a geodatabase Before After

22 Extra Slides for folks who download presentation from the AAUG Website

23 Data Model Basics What is a Data Model? A Data Model is any method of visualizing the information needs of a system and typically takes the form of an Entity Relationship Diagram (ERD). An entity is a person, place, thing of concept that has characteristics of interest to the enterprise and about which you want to store information What are types of Data Model? Conceptual Data Model (CDM) - A CDM represents the overall logical structure of a database, which is independent of any software or data storage structure. A conceptual model often contains data objects not yet implemented in the physical databases. It gives a formal representation of the data needed to run an enterprise or a business activity. Logical Data Model (LDM) - A LDM fills in the gap between a conceptual (CDM) and physical (PDM) data model. CDMs are completely devoid of database-level information while PDMs are specific to a certain DBMS. Since there are characteristics of databases that are generic in nature (such as indexes and foreign keys), a LDM stores those characteristics without adding anything specific to a single DBMS. Physical Data Model (PDM) - The PDM specifies the physical implementation of the database. With the PDM, you consider the details of actual physical implementation. It takes into account both software or data storage structures. You can modify the PDM to suit your performance or physical constraints

24 What ESRI Data Models are available? Administrative Boundaries Model Basemap Model Biodiversity Model Defense-Intel Model Electric Distribution Model Environmental Facilities Model Forestry Model Gas Distribution Model Hydrology Model Land Parcel Model Marine Model Petroleum Model Telecommunication Model Transportation Model Water Facilities Model Where can I find the ESRI data models?