GTK ArcGIS Chapter 14 Building geodatabases

Geodatabases, as the latest and most sophisticated spatial data format for ArcGIS offers advantages over coverages and shapefiles. Advantages include:

• ability to store multiple feature classes
• ability to store labels as annotation
• ability to create domains for attributes

A domain establishes valid values or ranges of values for an attribute field and minimizes data entry mistakes by prohibiting invalid entries (some may be due to simple typing errors). For example the attribute field for "Trail use" may be restricted to three valid entries: hiking, hiking and biking, hiking biking and equestrian.

We created a personal geodatabase, a type that is retricted in size to 2Gb with attribute tables stored in Microsoft Access format. This geodatabase included features for a city: fire hydrants(points), parcels (polygons), waterlines (lines) and valves (points). For features stored in a geodatabase, ArcGIS creates and maintains measurement fields such as the length of a line or area of a polygon. We added fields to attribute tables and created domains for the attributes.

A big advantage of a domain is that it can be applied to more than one field in a feature class and to more than one feature classs in a geodatabase.

We uploaded the geodatabase file we created.