1. Chapter 14
Geodatabases

2. Outline
Geodatabases
Types of geodatabases
Functional applications

3. Geodatabases
Designed to store feature classes for a particular geographic area.
Incorporates all feature classes, rasters, and tables in a single entity.
Feature datasets
Feature classes

4. Types of geodatabases Personal geodatabase File geodatabases
Stored in a Microsoft Access database format.
For single users and small workgroups.
2 GB size file limit.
Windows operating system only.
File geodatabases
Stored in folders
For single users and small to large workgroups.
1 Terabyte size limit.
Cross-platform operability (Windows, Unix, Linux)
SDE geodatabases
Stored in commercial RDBMS* (Oracle, SQLServer).
Designed for multiple simultaneous users.
Supports multi-user editing, versioned editing, etc.
Requires DBMS license and ArcSDE to translate data back and forth.
*Relational Database Management System

5. What goes in GDBs? Feature classes Feature datasets Tables Annotation
(collections of related feature classes)
Tables
Annotation
Relationships (formal persistent joins)
Planar topology classes
Rules about how feature classes interact spatially
Network topology classes
Enables modeling and analysis of network features

7. Functional applications
Geodatabases support a variety of data management functions to enhance work
Domains and Subtypes
Planar topology and spatial rules
Network topology and connectivity rules
Relationship classes (referential joins)
Versioned editing (SDE geodatabases)

8. Domains Rules about what can go in attribute fields.
Reduces data entry and consistency errors.
Coded domains
Set list of allowable values
Range domains
Set range of allowable values
Pipe size: 1”, 3”, 6” or 12”
Percent:

9. Subtypes Integer-coded classes of features.
Automatic display with different symbols.
Behave as different layers during editing.
Each subtype can have own default values.
Streamlines attribute entry.

10. Planar topology Set up rules within and between layers
Must not overlap
Must not have gaps
Must not self-intersect, etc.
Use during editing to ensure topologic consistency between features and feature classes.
Align county, state, and reservation boundaries

11. Network topology Create networks to analyze traffic, utilities
Connectivity rules
12” pipe connects to 6” pipe only through adapter
Find path
Trace downstream

12. Versioned editing SDE geodatabases only.
Allow multiple users to edit geodatabases simultaneously.
Can resolve conflicts between edited versions.
Can test “what-if” scenarios.
Can roll back to previous versions in case of failures.

13. Schema
A schema is a full description of all the feature classes, tables, fields, topology, and relationships in a database.
May be grown through time as database is haphazardly assembled.
May be designed ahead of time to fulfill specific organizational needs.
Can be downloaded, shared, and customized.

14. References Price, M. (2013). Mastering ArcGIS (6th ed.). McGraw-Hill
Price, M. (2013). Mastering ArcGIS (6th ed.). McGraw-Hill. Mastering ArcGIS, 6/e Instructor Edition Chapter 14: PowerPoint Notes and Figures