Preserving a GlobalID while moving data between Feature Classes

[alex_friant]

The spirit of this post is to gather other people's solutions, discuss ways of improving the suggested solution, and track future ArcGIS capabilities as they evolve for this problem.

This all started because we had existing data in a GDB that contained a Relationship Class (RC) between a Feature Class  (FC) and a Table (TBL) using the FC's GlobalID field. We wanted to move that data into a new GDB that had a new schema (changes in domains, fields, etc.).

The problem is that when you Append the old data into the new schema, the GlobalID in the new schema is different than the records from the old data. This breaks the relationship between the FC and the related TBL.

UPDATE 2:

I've got some bad news and I've got some good news. And some ugly details. But I also have steps/options.

The BAD news

The "New Solution" from my first update no longer works in Pro 3.x, as so kindly brought to our attention by @MichaelMannion a few days ago in this reply. Thanks Mike!

Basically, ArcGIS Pro no longer allows you to change the datatype for step #8 in the solution below. This breaks the solution I originally provided.

The GOOD news

ArcGIS Pro 3.x now respects the "Preserve GlobalID" environment option in the Append tool, but with very specific parameters. It works if the target database is either Enterprise Geodatabases and Mobile Geodatabases, but not File Geodatabases.

The UGLY details

In order for the Append tool to actually preserve the GlobalID from your source to your target, you still need to check the "Preserve GlobalID" environment option in the Append tool. 

You can only get it to work with Enterprise Geodatabases (EGDB) and Mobile Geodatabases (MGDB) as your targets, as no longer works with File Geodatabases (FGDB). Here's why.

The target GlobalID field must have and index that is configured as "unique". You can't make a GlobalID field that has a unique index in a FGDB.

Unique and ascending indexes are not supported for shapefiles or file geodatabases. These parameters are ignored when the tool is executed on a shapefile or file geodatabase data.

A 'unique' index can only happen if:

• the table/feature class is in an EGDB /MGDB
• you add the GlobalID to the table/feature class using ArcGIS Pro (3.x+)
  • alternatively, copy/pasting the empty target table/feature class into an EGDB or MGDB will automatically change the index to 'unique' for GlobalID in the paste target

When you follow those two parameters, the index that gets automatically created for the GlobalID field that is has the unique setting.

If your target field is a GUID datatype, it must also have a "unique index". You must use add the index in ArcGIS Pro, on an EGDB table/feature class, and make sure the "unique" checkbox is selected before you run the Add Attribute Index tool.

The STEPS for Enterprise Geodatabases/Mobile Geodatabases

Below I only refer to EGDB, but if you're using a MGDB the same steps apply.

1. Make sure your target table/feature class is in an EGDB
   1. If you have an empty table/feature class sitting in a FGDB but the indexes are not "unique", just copy them over to the Enterprise Geodatabase using ArcGIS Pro (3.x+)
2. Make sure your target field in the table/feature class has a "unique index"
   1. GlobalID
      1. If you already have a GlobalID field, but the index is not unique you need to replace your table/fc with a new one
         1. Export it to a local FGDB, but make sure to remove GlobalID following these steps.
         2. Delete the original target from the EGDB
         3. Replace the original target with a copy of your table/fc that has no GlobalID
         4. In ArcGIS Pro (3.x+) add GlobalID's to the target table/fc (right-click>Manage>check the box for  "Global IDs")
         5. Confirm that the index for the GlobalID field is in fact "unique"
   2. GUID
      1. If you already have a GUID, but the index is not unique, you need to delete the index
      2. Then you need to use the Add Attribute Index tool to create an index for the GUID, and make sure you check the box to have it be "unique"
      3. Confirm that the index for the GUID field is in fact "unique"
3. Now your EGDB target table/fc fields are ready!
4. Open the Append tool
   1. Under Environment, check the "Preserve GlobalID" box
   2. Under Parameters, append as usual

Once your data is in the updated schema, you can copy/paste it over to a File Geodatabase if you need to (for a deliverable or something).

The STEPS for File Geodatabases

All hope is not lost for users who must be restricted to File Geodatabase only. (But really, there is no reason to be afraid of the Mobile Geodatabase as a in between step, it works well!).

Thanks to user @DirtDogRoj in his excellently documented reply you can follow clearly outlined steps to achieve the same result. I think you could put it into Model Builder even as all the steps very systematic. You might like this method better just because! 😉

Pay no attention 2:

UPDATE 1:

I have a much, MUCH, better solution that I discovered and it doesn't appear to be documented anywhere. All the text below that has strikethrough you shouldn't pay attention to, as it was the old, convoluted solution.

New Solution:

1. Have your old data ready to load (your "loading" gdb - this is your source data)
2. Have your empty geodatabase with the new schema. (your "new" gdb. It's okay that it has the "GlobalID" field, there is a new way to populate it with the GlobalID values from your loading geodatabase in ArcGIS Pro.)
3. Open ArcGIS Pro
4. Make sure your two geodatabases are added to the project (the "loading" gdb and the "new" gdb)
5. Run the Append Tool
6. Use your loading gdb feature class as the source, and your new gdb feature class as the target
7. For the tool's Environment settings, make sure the "Preserve Global ID field" checkbox is checked
8. In the Append tool's Field Mapping section, under the "Properties" tab, change the target feature class Data Type for the GlobalID field from "GlobalID" ---to----> "GUID". (I know, this seems strange. The data type is set in the target feature class schema as "GlobalID", but if you don't change this to GUID, then the GlobalID values from your source feature class will not migrate over to your new FC. If you change this setting to "GUID", they will magically migrate over to your new FC! I don't believe this is documented. If someone sees this documented anywhere, please share in the comments!)
9. Repeat steps 4-8 for your related table.

Pay no attention 1:

After doing some searching, I discovered that there is a way to do this using and Enterprise Geodatabase (EGDB) and ArcGIS Pro.

I post my basic workflow here on how to preserve the FC's GlobalID values so that when you migrate the data over to the new schema, the GlobalID values stay the same in the new FC. This preserves the relationship between the FC and the TBL in the new schema.

Assumptions:

• You have a FC you need to migrate to a new schema and would like to preserve the GlobalIDs.
• You have access to an EGDB and ArcGIS Pro

Manual Steps:

1. Copy the source FC (Feature Class) to an EGDB (Enterprise Geodatabase)
   1. Rename each class to have "_OLD" appended to them
      • Note: You might need to deal with differences in domains at this point if they have the same name but have different contents
      • You don't want your final domains to be appended with "_1". If so, then after you copy them over, you will need to turn off the domains where they are used, and delete them in the EGDB
      • This doesn't affect final product because this is only happening in the source data
2. Prepare your new schema of your target FC to have a "GlobalID" that can be preserved:
   1. Take a copy of the FC empty schema
      1. Use X-Ray in ArcCatalog to remove the GlobalID field in the FC
      2. Create a new GDB using this new FC design
   2. Create a new "GlobalID" field manually (don't use the GP Toolbox) in the FC
      1. Use "GUID" datatype
      2. Do this in the FCL for the Global ID's that need to be preserved - this is normally only necessary on the FC where there is a oneway relationship
   3. Copy the FC to the EGDB
   4. In the newly copied FC in the EGDB…
      1. Create a new index for this new "GlobalID" field
      2. Make sure that it has "Unique" box checked, and "Ascending" too
3. Append records from the OLD FC to the NEW FC using ArcGIS Pro's Append tool
   1. Add the FC's to an ArcGIS Pro project
   2. Run the Append tool
      1. Make sure to have the "Preserve GlobalID" box checked under Environments
      2. For "Schema Type", use the "Use the Field Map to reconcile schema differences" option

At this point, you can now copy/paste that new FC back to your location of choice, and rebuild the RC so that it connects up with the new TBL. It turns out that the GUID's used in the related table to relate back to the FC are naturally preserved by using the Append tool in ArcCatalog, so performing the workflow above on the related TBL is unnecessary. Even though the TBL's GlobalID (not GUID) values change when moving the data, that's doesn't matter to us because they aren't used to create the relationship.

We don't do this often so we aren't going to take efforts to automate it, but I assume that might be possible.

[MitchHolley1]

Another idea is memorialize the GlobalIDs in the Feature Class (create new field called [GBL_GUID], GUID type --> Field Calculate the [GBL_GUID] field to the values in GlobalID).  Now, if you export any data from that Feature Class in whatever database format.. the relationship will be maintained through the new [GBL_GUID] field.  

[alex_friant]

Great answer, thanks! Your solution is better because once the change is made, then I never have to deal with the issue again after changing schemas. Thanks again.

[alex_friant]

After further testing, Mitch's solution won't work for us. The GUID field created doesn't autopopulate with a GUID in either ArcMap nor ArcGIS Online once deployed. Unless there is another trick to it, I'll have to stick to my original solution.

[MitchHolley1]

Have your DBA to a SQL update to the rows every x amount of time.

[alex_friant]

The data is to be hosted in AGOL eventually, so hacks won't work.

[ThomasColson]

Will since you have an EGDB.....this is another one of those "Tech support will disown you" hacks #if they catch you doing it but...

In SQL Management Studio, change the object_flags to 4 (from 256) and sde_type to 14 (from 12) for the GlobalID column in SDE_column_registry for both feature classes. Then do you move. Remember to change them back!

[alex_friant]

Thomas, check out the update in my original post. I found a very simple, supported, non-hack way to do this using ArcGIS Pro.

[ThomasColson]

very handy! I wonder if this can be mixed with some other python tools for archiving and downloading between AGOL and on-premise databases to achieve a true "two-way" sync without having to rely on flaky portal or pay for a data interop license. 

[alex_friant]

I don't see why not. The Append Tool should be scriptable, but I haven't had time to look into that yet. It's a good idea!