Take your data management to new heights: Your questions answered - Part 1
We’re answering your questions from our “Take your data management to new heights with geodatabases” webinar in a two-part series. In this first post, we cover general geodatabase questions and attribute rules.
Attention all geospatial enthusiasts! Are you ready to continue soaring to new heights with geodatabases? During our recent webinar Justin Brassard from Support Services, and I discussed how geodatabases in ArcGIS Pro are essential tools for managing and analyzing geospatial data.
For a recap of what we covered, take a look at our webinar recording.
We will be answering your top questions on geodatabases to help you become a skilled pilot in your field. Buckle up and get ready to continue learning how geodatabases can take your geospatial projects to new heights!
Mission critical question:
Before we lift our wheels and launch into the Q&A, we'd like to take a moment to address a critical question that has been raised time and again by fellow GIS professionals.
Q: I’m still using ArcMap, though I know I must switch to ArcGIS Pro soon. I’ve only been using shapefiles until now. Is it worth trying to use geodatabases now, or wait until I switch?
A: Yes! Now is a great time. Don’t wait to start working with geodatabases, even if you have not made the move to ArcGIS Pro quite yet. Geodatabases offer many advantages over shapefiles in folders regardless of which ArcGIS Desktop software you are using because of their increased storage capacity and additional functionality. Getting started with geodatabases is a great way to gear up for your future transition to ArcGIS Pro because while shapefiles are still supported, feature classes in a geodatabase are the default for all tools being run in ArcGIS Pro.
With that in mind, let’s look at some of your more general questions about geodatabases.
Getting Started with Geodatabases:
Accurate and reliable spatial data is essential for successful mission planning and execution. A geodatabase is a powerful tool in our arsenal, specifically designed to store and manage geographic data. Whether we're working with images, features or attributes, a geodatabase provides the structured framework we need to manage spatial data at any scale. It's a key component of our GIS infrastructure, providing advanced capabilities such as data validation, topology and relationship management that are critical to our operations. From mission planning to execution, a geodatabase is a key asset that allows us to deliver accurate analysis.
Q: Are non-feature datasets (e.g. tabular data, rasters, etc.) stored within the file geodatabase?
A: Yes! File and enterprise geodatabases both support diverse types of GIS data that can be used by ArcGIS, such as attribute data, geographic features, satellite, and aerial images (raster data), surface modeling or 3D data, utility and transportation network systems, GPS coordinates and survey measurements.
File Geodatabase can store multiple data formats, including tables, feature classes, relationship classes, raster datasets etc.
Q: Is the spatial reference set for the geodatabase, or can each feature dataset have its own spatial reference?
A: No, the spatial reference is not set for the geodatabase. The spatial properties, including the spatial reference, are stored at the dataset level. You could have feature classes with many spatial references in the same geodatabase. Feature datasets, however, have a spatial reference, so if you are using these to manage your data within the geodatabase, each feature within the dataset would need the same spatial reference.
Q: Can I store 1 TB of data in a file geodatabase? Is there a size limit?
A: File geodatabases themselves have no size. The limit is for the individual features in the geodatabase. The size limit for an individual table or feature class in a file geodatabase is 1 TB by default. If this is not large enough for your data needs, you could store up to 256 TB in a single feature with the use of key words. Read more about key words here.
Q: Can permissions be set on feature classes and feature datasets in a file geodatabase?
A: In file geodatabases, permissions can be set at the geodatabase level only, using the Windows file system permissions. This means that access to the entire file geodatabase is controlled by the file system permissions that are set on the folder that contains the file geodatabase and they cannot be set on the features themselves.
However, in enterprise geodatabases, which are built on a multiuser relational database management system (RDBMS), permissions can be set at the geodatabase level as well as at the feature class, feature dataset and row levels using Access control lists (ACLs).
Q: Can you move existing feature classes into a feature dataset, or do they need to be newly created features?
A: Yes, if the existing feature has the same spatial reference as the feature dataset it can be moved there.
Q: What is the difference between a shapefile and a feature class?
A: Both shapefiles and geodatabase feature classes are a collection of common features that share geometry and attribute fields. One of the main differences between the two is that geodatabase feature classes are object-based containers storing all this data in a single item. Comparatively a shapefile is stored in a folder. A shapefile is made up of multiple files and all files must be found in the same folder with the same name. If the individual files do not have the same name and are not in the correct location, the shapefile will fail to open in a GIS application. As a shapefile is a basic storage format it has several limitations including:
- Consume higher storage.
- Only allow for 2GB of data storage.
- Fields cannot have more than 10 characters.
- Date and Time cannot be stored in the same field.
- NULL values are stored as 0 instead.
While geodatabase feature classes do not have these limitations, the major difference between the two file types are the additional functionality they come with including:
- More reliable – less likely to experience file corruption.
- Complex/ high precision geometry options.
- Support geodatabase topology.
- Support domains and subtypes.
- Ability to have annotation feature classes.
Overall, working with geodatabase feature classes allows for increased performance and greater functionality when working in ArcGIS Pro.
Attribute Rules:
When it comes to spatial data every detail matters. Attribute rules in ArcGIS Pro are the ultimate aid for maintaining data accuracy and consistency. These powerful tools allow you to validate data entry or make calculations based on changes made to specific fields in your dataset. Stored as metadata, attribute rules can be applied to any feature class or table, providing a streamlined and powerful data management workflow. With attribute rules at your disposal, your data is always mission ready.
Q: What types of attributes can be validated or constrained?
A: Any type of attribute including text, numeric date, and spatial data can participate in an attribute rule. You can use attribute rules to ensure that attributes meet specific criteria, such as being within a certain range of values, having a specific format or being in a certain place.
Q: Can attribute rules be used on hosted feature layers in ArcGIS Online for editing in web maps and apps?
A: No, attributes are not currently supported in ArcGIS Online and if features are published from ArcGIS Pro to ArcGIS Online with attribute rules applied, the rules will not transfer. If this is the functionality you would like to see added in the future, we recommend that you support the existing idea posted on the Esri Community page.
Q: How can I view the results of attribute rules validation?
A: You can view the results of attribute rules validation in several ways, including by using the Attribute Validation pane, which displays a summary of validation results and any messages or errors generated by attribute rules. You can also view the results of attribute rules validation in the geodatabase editor, where invalid features or attributes will be flagged with a warning symbol.
Q: I am not familiar with Arcade, where can I learn more to get started with attribute rules?
A: There are many resources to help you get started with using Arcade. Depending on the format you prefer there are a few different resources we have included that you can check out:
- Arcade’s Fire Inside Esri’s Scripting Language – Esri Canada Webinar
- Attribute Rules in Arcade (From Scratch) – Demo Theater Video
- Your Arcade Questions Answered – Blog Post
Q: Can I work with attribute rules for my feature classes in ArcMap?
A: Attribute rules are not compatible with ArcMap. To use attribute rules, the feature class must be upgraded to work with ArcGIS Pro 2.1 at the earliest. If an attribute rule is added to a feature class within a feature dataset, the entire feature dataset will not be accessible from ArcMap. While it may be possible to view some of the other feature classes within the feature dataset, editing will not be possible.
That covers all your questions about geodatabases and attribute rules. Stay tuned for more part 2 where we take on your topology, subtype and domain questions, coming soon!