ArcCatalog and Geodatabases

Francisco Olivera, Ph.D., P.E.Srikanth Koka

Department of Civil EngineeringTexas A&M University

ArcCatalogArcCatalog is one of the three components of the ArcGIS software. The other two are ArcMap and ArcToolbox.

ArcCatalog has advanced capabilities for accessing, managing and previewing data.

Main menu

Catalog Tree

View Type

Display

Preview Type

Standardtoolbar

View TypesThere are three different types of views for data display:

ContentsPreviewMetadata

Folder ConnectionTo access the data in a folder or geodatabase, a connection has to be established.

To establish the connection, click on the Connect to Folder button.

In the Connect to Folder wizard, navigate to the folder or geodatabase that contains the data and click OK.

Preview

Geography Preview Table Preview

MetadataThe metadata view in ArcCatalog can be used for viewing information about the data.

Metadata can be created, edited, imported or exported using the Metadata toolbar.

Geodatabase

A geodatabase is a relational database that contains spatial and non-spatial objects.

Types of Geodatabases

Personal Geodatabases:Have .mdb extension.Can be viewed by multiple users but edited by only one user at a time.Have a maximum size of 2 Gigabytes.Do not store raster data.

Multi-user Geodatabases:Require ArcSDE and a DBMS ( Data Base Management Systems).Can be read and edited by multiple users at the same time.Can store raster data.

Personal Geodatabases

Importable Data Types:Coverages Shapefiles CAD drawingsINFO tablesDBF tables

Can be opened with ArcCatalog and MSAccess.

Geodatabase Elements

GeodatabaseFeature Dataset

Feature Class

Geometric Network

Table

Relationship Class

Workspace

Feature ClassA feature class is a collection of geographic objects in tabular format that have the same behavior and the same attributes. All feature classes have a field named “Shape.”

A feature class can be stored at the geodatabase root or in a feature dataset.

New feature classes can be created using ArcCatalog. To do this, right click on a geodatabase or feature dataset, and point to New/Feature Class.

Feature Class Types

Point

Annotation

Line

Polygon

TablesA table (or object class) is a collection of non-spatial objects in tabular format that have the same behavior and the same attributes. All object classes have a field called “ObjectID,” sometimes also called FID or OID.

Tables can be stored at the root level of geodatabases but not inside feature datasets.

Table format supported: INFO, dBase and others.

Attribute DomainAttribute domains are used to constrain the values allowed in any particular attribute of a table or feature class.

There are two different types of domains

Range Domains• Define a range of

acceptable values for an attribute

Coded Value Domains• Define a set of

acceptable values for an attribute

Domain Properties

Field Type: Text, short integer, long integer, double, date, etc.

Domain Type: Coded values, range

Split policy: Duplicate, default or geometric ratio

Merge policy: Default, sum, weighted average

SubtypeSubtypes are subsets of feature classes and tables.

Objects in a class can be differentiated based on attribute values attached to the features.

Example: A feature class that represents roads can have two types of roads - US Highway and Interstate. Each type forms a class subtype.

Feature DatasetA Feature Dataset is a collection of feature classes that have the same spatial reference.

Feature datasets can also store relationship classes and geometric networks, but not tables.

New feature datasets can be created using ArcCatalog. To do this, right click on a geodatabase, then point to New/Feature Dataset.

Feature Dataset Properties

The Feature Dataset Properties wizard can be used for viewing or defining a feature dataset’s spatial reference properties.

RelationshipsA Relationship is an association or link between two objects in a database.

A relationship can exist between spatial objects (features of feature classes), non-spatial objects (records of tables), or between spatial and non-spatial objects.

RelationshipsRelationship between non-spatial objects

State Name and code

State Population

RelationshipsRelationship between spatial and non-spatial objects

Non-spatial data

Spatial data

RelationshipsRelationship between two spatial objects

Spatial data

Spatial data

Relationship ClassA relationship class is an association between two object classes (i.e., feature classes or tables).

Relationships can be one-to-one, one-to-many or many-to-many.

Can be created and edited using ArcInfo or ArcEditor only, but can be accessed with ArcView.

Can be inside or outside feature datasets.

Relationship Class

ReferencesMac Donald, “Building a Geodatabase”, Environmental Systems Research Institute (ESRI), Redlands, Calif

http://www.ce.utexas.edu/prof/maidment/giswr2003/visual/lecture22003.ppt

http://mark.gisc.kennesaw.edu/4405/Geodatabase.pdf

http://visc.sis.pitt.edu/resources/tutorials/GIS/Geodatabases.pdf

http://www.gis.state.ar.us/Downloads/GIS/presentations/Geodatabase%20101.pdf