imagine yourself or others having to edit this data, or even think about how you might use the data in a geoprocessing task. Perhaps you’ve used a poorly designed dataset before and spent a large amount of time formatting the data just to make it usable. If you can remember what problems arose and what steps you took to correct them, you will have a good understanding of how to create your datasets and avoid those mistakes.
It may also help to imagine what a final output map containing this data might look like so that you can determine what fields to use for labeling and symbolizing. The field types you design will make calculations either very easy or very difficult. Labeling will either be a snap or a headache. All these things can affect the design of a geodatabase, and a good design will make all future work that much easier.
Tutorial 1-1: Creating a geodatabase—building a logical model
The newest release of ArcGIS® Desktop software includes many additions and improvements to the data storage capabilities of the Esri® geodatabase file structure. There are new techniques to control interactions with the data, assign a behavior to it, and define relationships among datasets. In the design process, it is important to understand these techniques to build the most efficient database possible. It is even possible to build data controls to aid the user in creating data while decreasing the chance of introducing errors into the dataset. This book was tested using ArcGIS Pro 2.3.
LEARNING OBJECTIVES
•Outline geodatabase behavior
•Integrate datasets
•Model reality
•Use ArcGIS® Pro
Introduction
The goal of designing a geodatabase is to model the reality it is intended to represent. There are many characteristics, or behaviors, of the data that can be included in a geodatabase using various techniques. As the data modeler, it is your job to explore the capabilities of ArcGIS to make the most efficient and flexible database possible. The time spent at the start of a project designing the geodatabase will reap rewards later by making the data easier to use and edit and presenting a better representation of reality.
The first step is to study the reality that is about to be modeled. Look carefully and determine what features must be included in the geodatabase. In ArcGIS, everything is modeled as points, lines, and polygons, so realistic characteristics will need to be assigned to these pieces.
Next, look at how the data will be created. Will it be imported from another source, collected with field equipment, traced from aerial photos, drawn from survey data, or derived from some other process?
Finally, consider how this data will be used. Who will perform the edits, and what queries might it be expected to support in the future? Knowing many of the questions that the data will be used to answer will shape the geodatabase design.
With these things in mind, you can start to construct a logical data model. The model will diagram your process and allow for updates and changes before the final design is committed to a geodatabase. The design process uses a spreadsheet-based form to enter all the characteristics of the geodatabase, the feature datasets, the feature classes, and the data integrity rules of the feature classes such as domains and subtypes. Microsoft Excel® spreadsheet files included with the exercise data follow the creation process in ArcGIS Pro that will be used for basic diagramming.
The logical model is used to show what data types you will have (points, lines, or polygons), what tabular data will be included in the dataset, and the relationships between the tabular data and feature classes (if any). The model is also easily shared among your colleagues, so you can get several opinions on the design you are attempting.
Once a preliminary logical model is completed, it can be checked against many of the advanced features of the geodatabase, such as domains, subtypes, and relationships. Have the best tools been employed to ensure data integrity, ease of editing, and future expansion? You will also check the geodatabase against your idea of how the data should behave.
The result should be a well-thought-out geodatabase that is both efficient and a good representation of reality . . . well, at least as close as you can get using points, lines, and polygons.
You will start with a simple geodatabase, and then examine several advanced geodatabase options to see if better efficiency and more realistic behaviors can be achieved. The good news about any geodatabase design is that if it works, it’s a success. Ten different people could design 10 different geodatabases for the same project, and they all could work quite well. The true test is how efficient a geodatabase is, how well it models reality, how well it maintains data integrity, how flexible it remains for future projects, and how easy it is to work with in editing and extracting information.
Designing the data
Scenario
The City of Oleander, Texas, population 60,000, has hired you as the top-gun geodatabase designer and wants an all-new database design for its parcel data. The new geodatabase will be used to designate each piece of property in the city—who owns it, its legal description, address, and more. You’ll get information from the city planner to get the full idea of what’s needed, and then create a diagram of your proposal. At this point, the geodatabase will not be constructed, only designed.
The city planner describes a dataset that would have a polygon for each piece of property in the city, whether it is platted or unplatted. It should have information about the legal description, the street address, and the current usage of each property.
Data
Because you are creating this geodatabase from scratch, there is no data to start with. You will need to print the geodatabase design forms from the exercise materials you download from ArcGIS® Online and use them to document the design process.
Tools used
•Geodatabase design forms
Begin the logical design for the geodatabase
The main component of this geodatabase will be polygons representing every piece of property in the city. Each piece of property is assigned certain data by the city. This data includes the subdivision name, block designation, lot designation, street address, and a land-use code, which shows how the land is being used.
As you know, the geodatabase is the framework in which other components are built. It may contain feature classes, tables, relationship classes, feature datasets, and many other components. You will design the geodatabase and its components using the geodatabase design forms provided in the files you download for this book.
Access the data
The data is stored in a book group named Focus on GDBs in ArcGIS Pro (Esri Press) in the Learn ArcGIS organization. You will log in and access the files for this tutorial, as well as for all the tutorials and corresponding exercises in this book as you need them.
1.Go to https://www.ArcGIS.com, and log in with an ArcGIS Online account.
2.On the Home tab, type Focus on GDBs in ArcGIS Pro in the Search box, and then click the Search for Groups entry in the drop-down list. (If no groups were found, turn off the option to “Only search in your organization.”)
3.Click the link to open the Focus on GDBs in ArcGIS Pro (Esri Press) group and find the data, named FocusGDB. It consists of a zip file for each
