Working with the Geodatabase

Agenda

• What is the geodatabase?• Benefits of the geodatabase• Inside the geodatabase• Geodatabase rules• Demos• Additional resources and training• Q & A

The Geodatabase is the foundation of ArcGISOrganizing & Managing Geospatial Data

. . . Essential for Leveraging the Full Capabilities of ArcGIS

Networks

Surveys

Addresses

Annotation

Vectors

3D Objects

Topology

Dimensions

Images

Terrain

Attributes

Cartography

Cadastral

Schematics

ArcGIS

Geodatabase

Comprehensive Information Model(Any Type of Data)

• Any DBMS• Files

Scalable Storage Environments

The geodatabase is…

• Storage container for spatial information

• Business rules

… data integrity for comprehensive GIS mapping and analysis workflows

Feature dataset

Terrain

Topology

Network dataset

Geometric network

Feature class

LinePolygon

PointDimensionAnnotation

Route

Relationship class

Table Raster dataset

Raster catalog

Survey dataset

Project folder Project

Toolbox

Tool Model Script

Schematic dataset

BehaviorRelationship rulesConnectivity rulesTopology rules

Attribute domainsAttribute defaultsSplit/merge policy

Inside the Geodatabase…

Geodatabase benefits

• There are many!• Let’s explore the geodatabase through the many benefits it

provides for your GIS workflows

The geodatabase stores spatial data

• A table with a Shape/Geometry column– Feature classes

• Shape types– Points– Lines– Polygons– Multipatch

• Additional benefits – Not just “X and Y”– Z’s and M’s– True curves– Multipart features– High precision

Feature with many parts – one row in table.

Storing geometry is fundamental to the geodatabase

• Knowing the area and length of features you maintain is critical– Fundamental to GIS problem solving tasks you do every day

• The geodatabase manages and maintains:– Area– Perimeter– Object ID (System managed ID)– Spatial reference (Projection)

… “measuring” is a fundamental GIS task.

Raster data can be stored in the geodatabaseBeyond vector

• Raster dataset• Raster catalog (a collection of datasets)• Raster attributes

The geodatabase rules

• The power of the geodatabase• Modeling the real world:

– Parcels cannot overlap– Roads are connected and traversable– Districts might overlap in some cases– Trees are only a certain type– A green widget is different than a red widget

Data creation

Data Usage & AnalysisData "clean up"

Domains

• Describe the legal values of a field type– Used to ensure attribute integrity

• Types of domains:– Range

• A tree can have a height between 0 and 300 feet– Coded Value

• A tree can be of type oak, redwood, or palm

A

Pole

Steel

Wood

<<subtype>>

<<subtype>>

Steel HeightDefault = 50MinValue = 30MaxValue = 75

SplitPolicy = defaultMerge Policy = sum

Wood HeightDefault = 30MinValue = 25MaxValue = 40

SplitPolicy = defaultMerge Policy = sum

domain

domain

Subtypes

• Partition the objects in a feature class into “like” groups, i.e. ‘Type’, ‘Code’, ‘Class’ attributes

• Benefits of using subtypes:– Rules (e.g. domains) for other attributes can be based on subtypes– Provides an opportunity to manage data in one location (i.e. one table)

instead of separating out into multiple tables or feature classes– ArcMap “knows” about subtypes when adding data

CodesDescriptions

Relationships between tables

• Relational database concept– But we often perform this at the layer or map document level

• An association between two sets of records IN the database– A table may participate in multiple relationship classes– ArcEditor/ArcInfo to create; ArcView will read-only

• Simple relationships and Composite relationships– Can trigger an action (cascade delete, move to follow, custom, etc.)

ParcelToBuilding

Spatial relationships

• A special category of spatial data rules• Fundamental for spatial data storage

– i.e. Good data• Fundamental for real-world decision making

– i.e. Good decisions

Coastline

Country boundary

Roads

Bus route

Proximity

Pipes Streams

Connectivity

Land parcels Soil

Adjacency

Geodatabase topology

• Manages feature classes that share geometry– Coincident geometry– Data integrity rules– Topological relationship queries (for example, navigating feature

adjacency or connectivity)– Sophisticated editing tools

• Geodatabase Topology Rules

Migrating data into the geodatabase is workflow driven

• Straightforward tools make it possible– e.g. Copy/Paste or Right-click export– Import/Export CAD, Shapefile, Coverage, other formats– ArcCatalog & ArcToolbox provide the end user framework

• But, there are other pathways if your workflow requires more flexibility

– Capturing workflows in Geoprocessing models and scripts– ArcCatalog Simple Data Loader– ArcMap Object Data Loader– XML

Demo recap: Feature datasets

• A container object for feature classes and objects

– Same spatial reference

• Container for networks and topologies

– Must use feature dataset

• Design considerations– Start Editing operations– Not a “folder”– ArcScripts

ParcelCorner

Parcel

ParcelAnno

LotLines

Parcel_Topo

LotDimensions

Subdivision

BoundryLines

Demo recap: Object Loader vs. Simple Data Loader

• Simple Data Loader– ArcCatalog/No edit session

• Object Loader – Loads data in an ArcMap edit

session– Undo/Redo supported– Snapping environment supported

• Use Object Loader for:– Geometric networks, feature

classes in a relationship with messaging, or feature classes that have feature-linked annotation

– Geodatabase rules

1. ArcCatalog feature class context menu:

Simple data loader

2. ArcMap Customize dialog:

Object Loader

Demo recap: Topology workflow

• Designing– Choose feature classes– Choose tolerances– Choose rules

• Creating– ArcCatalog or Geoprocessing framework

• Validating– Find errors using chosen tolerances, rules, and input features

• Editing– ArcMap advanced Editing tools (ArcEditor/ArcInfo required)– Error fixing tools– Revalidating

• Topological querying– Find adjacent; find connected – ArcObjects developer samples

Demo recap: Geodatabase validation

• Validation– ArcMap Editor workflow process– E.g. Domain > Validate– Topology Validate

• Could be automated to tailor your specific data maintenance workflows

– Geoprocessing tools, scripts, models– ArcMap can be extended using the customization framework (e.g.

ArcObjects)

Geodatabase also captures specialized GIS workflows

• Cartographic production workflows– Text on maps– Standardization of symbology

• Business/Industry specific workflows– e.g. Pipelines or water lines have specific characteristics beyond

being “just lines”– E.g. Land record parcel is not just a “polygon”

• Other applications (non-industry specific)– e.g. Streets have specific characteristics beyond being “just lines” –

and are useful to many GIS professionals – not just Transportation planners

– e.g. Street addresses and address mapping processes

…specialized rules and objects that make spatial data more useful

Topanga Canyon

Sacramento

Placerville

feature classannotation feature

classcomposite

relationship class

94 Sacramento

95 Topanga Canyon

92 Placerville41434749

929495

414347

212327

Annotation: Text on a map

• Storage options:1. Map document or2. Geodatabase

• Non-feature-linked geodatabase annotation– Not tied to spatial feature (feature & attribute(s))– ArcView licensing

• Feature-linked geodatabase annotation– Uses composite relationship class– ArcEditor/ArcInfo license needed to create & edit

Cartographic representations

• Advanced symbolization for map features– Symbolize a feature and its geometry independently– Additional set of symbology rules and effects

• Stored in the geodatabase– Property of a feature class– Rules, Overrides are attributes

• Requires:– ArcInfo (all Geoprocessing tools)– ArcEditor (Creating/Editing)– ArcView (Read only/use)

Industry specific geodatabase rules

• Utility networks– Collections of feature classes and tables– Flow, direction, sinks/sources, and special connectivity rules– Solvers: real world questions and problems specific to those rules– Out of the box (ArcEditor/ArcInfo)

• Transportation Networks– Collection of feature classes and tables– Direction, restrictions, impedances, costs and special connectivity

rules– Solvers: real world questions and problems specific to those rules– Network Analyst Extension (ArcView/ArcEditor/ArcInfo)

• Cadastral fabrics– Survey Analyst/Cadastral Editor– Land records management solution

The geodatabase is scalable

• As organizational needs and challenges change through time– Your geodatabase rules can change and evolve, too– Your geodatabase rules are still meaningful– Your investment is paying off

3 Types of geodatabases

• Personal geodatabase– Single user editing– Stored in MS Access

• File geodatabase– Single user editing– Stored on disk

• ArcSDE geodatabase– Stored in an enterprise DBMS– Supports geodatabase versioning– Requires ArcEditor or ArcInfo for editing

PersonalGeodatabase Oracle

SQL ServerDB2

InformixPostgreSQL

ArcSDE

ArcGIS

FileGeodatabase

Personal GDB File GDB ArcSDE GDB(3 editions)

Storage format MicrosoftAccess

Folder ofbinary files

DBMS

Storage capacity 2 GB 1 TBper table

Depends onedition

Supported O/S platform

Windows Any platform Depends onedition

Number of users Single editorMultiple readers

Single editorMultiple readers

Multiple editors& readers

Distributed GDB functionality

Check out/check inand One-way

replication

Check out/check inand One-way

replication

Replication(all types)

& versioning

Geodatabase types: Capacities and other considerations

Editing geodatabases

• ArcGIS datasets stored in the geodatabase are editable– Editing in ArcGIS is based on a transactional model

• Edits are performed in an edit session– A series of edit operations constitutes a transaction– Unit of work performed against the database– The transaction is either committed or rolled back

• Editing needs to be flexible– Let users define what an “edit” means– Built around organizational skill sets and workflows– Honor and understand geodatabase rules

Editing geodatabases by type

• Personal geodatabases– Single user; “cubicle editing” on small datasets– Editing locks at geodatabase level

• Two editors cannot edit within the same geodatabase at same time

• File geodatabase– Single user; workgroup editing on small to very large datasets– Editing locks at the feature level

• Two editors cannot edit the same object/feature class at same time

• ArcSDE geodatabases – Extend the transaction model with Versions

• Enterprise-wide editing• Multiuser editing without locking

Some editing workflows require special needs

• Editing with long transactions– Isolate work across multiple sessions– Edits do not impact others– Example: Parcel editing

• Model what-if scenarios– Simulate situations with versions– Example: Disaster event planning

• Workflow management– Create versions of data for project stages– Example: Land development

AnalystPublic

Farmland Residential

FloodPublic

Geodatabase versioning

• Multiple, virtual private workspaces• Concurrent edit work on the same features• Distributed (and disconnected) editing

– Geodatabase replication• A foundational technology for historical archiving

Additional management considerations

• Upgrades– Synchronization of geodatabase and application– Personal and file geodatabase– ArcSDE geodatabases

• Workgroup/Desktop• Enterprise

Summary

• The geodatabase is simply:

A storage container for spatial information and business rules.

• The geodatabase is designed:

To improve your GIS data management and quality control workflows important for trustworthy spatial decision making and problem solving challenges.

Additional resources

• ArcGIS Resource Centers– Blogs, Help, White papers, Getting Started…– Geodatabase and ArcSDE: http://resources.esri.com/geodatabase/

White papers

• Understanding Coordinate Management in the Geodatabase:– http://support.esri.com/index.cfm?fa=knowledgebase.whitepapers.vie

wPaper&PID=43&MetaID=1301• System Design Strategies

– http://www.esri.com/library/whitepapers/pdfs/sysdesig.pdf

ESRI Learning Center

• ESRI provides numerous Instructor-led options for the “Geodatabase”:

– Building Geodatabases– Geodatabase Design Concepts– Data Management in the Multiuser Geodatabase – Managing Editing Workflows in a Multiuser Geodatabase– MORE

• Virtual Campus– Many free and pay-for self-paced courses

http://training.esri.com/gateway/index.cfm