Geodatabase Design

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07-08-2010 08:31 PM
stephanieduce
New Contributor II
Hello,

I have a lot of data including roads, drainage, contours, land use, habitat, shorelines, marine protected areas (.shp) as well as DEMs etc.... for a group of islands. I would like to organise this data into one, or more than one, geodatabase(s). I have not worked with geodatabases before (though have done quite a lot of work with GIS) and am not sure how best to approach this.

- Would it be best to make my own data model or to add my data to an original data model such as ArcMarine etc...

- Should I create separate geodatabases to house the terrestrial data and the marine data? If I do will it be fine to work with them both simultaneously in ArcMap? They are both the same coord system.

- Would it be appropriate to divide each island's data (i.e. roads, infrastructure, buildings etc..) into a separate feature dataset within a geodatabase?

Any help will be much appreciated.
Thanks in advance,
Steph
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18 Replies
HardolphWasteneys
Occasional Contributor III
Stephanie,

the simplest starting view on setting up your geodatabase is along the lines of how you would organise the data in normal computer folders.  

Next what data do you want to be able to edit in the same session (all that should be in one gdb).  You can access as many geodatabases as you want in a project, but only edit from one at a time.

Even if coordinate system are not an issue the feature datasets make handy folders for organizing feature classes.  If different projections are used or you might want to reproject a set of feature class then sort them that way into feature datasets.  You can reproject a whole set of FCs at one go by reprojecting the feature dataset.

The next level of utility for the gdb is the use of domains for editing:  you can have any number of domains in one gdb and use them in all the FCs in that gdb.  So your different types of data terrestrial vs marine would use different domains, but they can all be available in the same gdb.

Other behaviour that requires ArcEDITOR or ArcINFO is also housed in the gdb (representations, topology etc.).

The only other considerations are size:  personal geodatabases have a limit of 2 Gb and only are mandatory if you require editing using Access. Otherwise just used File Geodatabases and stuff it full of all your data.  You can always make replicates.

As for data models that may be getting down to the design of individual feature classes and how various fields interact using subtypes and domains.



Hardolph
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DerekLaw
Esri Esteemed Contributor
Hi Stephanie,

This is a good place to start learning about some geodatabase design patterns and best practices:

An overview of geodatabase design

Hope this helps,
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stephanieduce
New Contributor II
Thank you very much for your useful tips Hardolph!
Yes the Overview is also very helpful and well written thank you Derek.
🙂
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stephanieduce
New Contributor II
Just one more question...
Hardolph you said that if I want to be able to edit using Microsoft Access I need to use a personal geodatabase. Does this mean that if I use a file geodatabase it can only be edited in ArcCatalogue?
Thanks, Steph
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DerekLaw
Esri Esteemed Contributor
Hi Stephanie,

Your statement is correct. A File geodatabase can only be edited using ArcGIS Desktop. An MS Access personal geodatabase (which is implemented on an MS Access file) can be edited using Microsoft Access - but is not officially recommended.

FYI: if you are going to start a new project, I recommend that you use a File geodatabase over an MS Access personal geodatabase. Please see this ArcUser article,

Top 9 Reasons to Use a File Geodatabase

Hope this helps,
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stephanieduce
New Contributor II
Thanks Derek,
That is helpful. I think a file geodatabase is the right choice.
The only thing I'm worried about is that in the organisation I'm working for not many people use or have any knowledge of ArcGIS or GIS at all. I still want them to be able to at least know what data is available and potentially view the metadata.
Can you think of a way to do this? I was thinking perhaps a wiki but it would probably have to be separate from the geodatabase.
Your help and advice is greatly appreciated!
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DerekLaw
Esri Esteemed Contributor
Hi Stephanie,

One of these developer samples might address what you're looking for. They enable the creation of a visual "schema-diagram" of the contents of a geodatabase:

1. ArcGIS Diagrammer 9.2/9.3

2. Geodatabase Diagrammer for ArcGIS 9

3. Geodatabase Reporter.NET (9.2)

Hope this helps,
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DavidStrip
New Contributor II
I'm struggling to get my arms about how a geodatabase is used. The example in the help shows a variety of feature classes relevant for mapping a town. These include wells, road centerlines, parcel boundaries, etc. So far, so good. If I'm mapping Smallville, I set up this geodatabase and populate the feature classes. Now I decide to map Gotham. I don't want to just add Gotham data to the Smallville data, do I? Does this mean I have to create another parallel geodatabase with the same structure, or can I somehow create "folders" within the same geodatabase, one to contain Smallville data, and another for Gotham?
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DerekLaw
Esri Esteemed Contributor
Hi David,

Does this mean I have to create another parallel geodatabase with the same structure, or can I somehow create "folders" within the same geodatabase, one to contain Smallville data, and another for Gotham?


Actually, you can do either option. It really depends on the requirements of your business workflow(s) and what you want to do.

Option 1: Have 2 separate geodatabases, one for each city. This enables each city to have and be able to maintain their own geodatabase, independent of each other.

Option 2: Have a single geodatabase, with 2 feature datasets (these are conceptually similar to "folders" - but contain data that are spatially related), one for each city. In this case, all GIS data is stored in one location, but the cities share ownership and access to the geodatabase.

This book is a good resource for learning about geodatabase design: Modeling Our World 2nd Edition by ESRI Press.

Hope this helps,
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