The term ArcSDE/SDE is being gradually replaced with the term “Multiuser Geodatabase” and this is probably creating some confusion among the users of the ArcGIS platform. In order to understand the difference between ArcSDE and multiuser geodatabase, let’s start clarifying what is and what is not ArcSDE.
What is not ArcSDE:
ArcSDE is not a product. It’s a technology. In the same way ArcGIS is not a product, is a platform. Only prior to ArcGIS 9.2, ArcSDE was a standalone software product. At the ArcGIS 9.2 release, ArcSDE was integrated into both ArcGIS for Desktop and ArcGIS for Server.
ArcSDE is not only the application sever connection, a piece of software that packs the giomgr.exe and a gsrv.exe processes. This is a common mistake that I have mentioned in my previous post but from a more business perspective. I’ll try to do the same exercise now but from a technical perspective.
So, what is ArcSDE – also called “the database enhanced with the ArcSDE technology” or simply the “ArcSDE geodatabase” or the “Multiuser geodatabase”?
This is a recurrent question in my geodatabase seminars.
“ArcSDE” is a concept that has always created some confusion, and part of the reason is, I think, due to how ArcSDE has evolved overtime.
I have seen that some users tend to associate the concept ArcSDE with the “application service connections” which has been deprecated in 10.3. Sometimes, I see people mixing things up and ending up asking questions like, “Has Esri got rid of ArcSDE?”
It’s also common to see users asking in forums why they should use ArcSDE if there are many databases that support spatial data, multi-user editing, replication, and even spatial functions, as one of colleagues here in the Melbourne office found the other day. The confusion comes from the terminology used:
Do I get the same spatial capabilities using native database spatial data versus ArcSDE enhanced spatial databases – even when both use the same spatial data types – for example, do I get the same capabilities using a MS SQLServer database using the Geometry spatial data type and a MS SQLServer ArcSDE enhanced database using Geometry spatial data type?
Is it the same multiuser editing found in SQL Server or any other database and the multiuser editing available with ArcGIS?
Is it the same “replication” functionality the one found in a database and the one we have with the Esri technology?
A short answer to all these questions is: – No, it is not the same.
Geodatabases are the central store for maintaining all your vector data for ArcGIS. Traditionally data integrity in a geodatabase is maintained with the use of versioning. Edits are made in a version. The data is quality checked and then published to the control version.
We are seeing an increasing need to maintain more than one copy of data with the advent of ArcGIS Online. Data is moved to cloud servers and ArcGIS Online to allow field editors and remote offices access to the corporate datastore. The concept of one centralised database is being eroded because of these requirements for multiple sources. Enter the geodata service. Residing on top of a versioned geodatabase, the geodata service allows organisations to replicate data through the firewall to cloud servers and ArcGIS Online – allowing users in remote office and field users to have access to and update the most current data.
Another common scenario is to have the GIS data in one geodatabase and corporate data in another. The ability to directly connect to these enterprise databases in ArcGIS and join and manipulate data is also highlighted.
In my blog post series so far this year, I have considered and written up common workflows for preparing data for ‘in field’ collection capture using the Collector for ArcGIS app.
If you’ve missed any of these blogs, you can find them using the Collector tag on this page.
So what’s the next step? Well, now that you’ve published the data, and used the Collector app to collect new features and you’re back at the office, you’d probably like to get the data from the “cloud” and do some good old editing or analysis in ArcGIS for Desktop.
This brings us to my current blog post! Here I’ll cover a few simple techniques that you may use to extract the data from a feature service that’s running on ArcGIS Online, and use it in ArcGIS Desktop. To illustrate this workflow I will use the same feature service representing traffic accidents that I’ve used to demonstrate the Collector’s “offline editing” workflows. Continue reading →
As map makers we use maps as a medium to convey and inform information to our readers, a pivotal part of our workflow is labeling our maps to help us.
By looking at the map below, I think we could use some better labeling and positioning make locating features easier. The labels for a few of the cities such as Darwin and Birdum are difficult to read as the boundary of Australia is overlapping and in the west Fremantle and Perth seem to be one city. Additionally we can see that there are two rivers but they are not labelled. It is also probably a good idea to label Australia.
Let’s get down to business and begin to clean up our map so our readers are able to better identify and locate features using different labeling tools. Continue reading →