topic Personal GDBs: How are feature classes and feature datasets linked? in ArcMap Questions

Personal GDBs: How are feature classes and feature datasets linked?

AlfredBaldenweck — Mon, 07 Aug 2023 20:17:59 GMT

Hi all,

Quick question today.

I have a personal GDB with two feature classes living in a feature dataset.

What I can't figure out is how Arc can figure out that they live there?

There is nothing in the feature class table linking them to the dataset, so how does Arc know?

Re: Personal GDBs: How are feature classes and feature datasets linked?

JohnPlunkett — Mon, 07 Aug 2023 21:40:19 GMT

Hello - if you are using Personal Geodatabases. - Can you consider Migrating to the file geodatabase—ArcMap | Documentation (arcgis.com)

This is especially important if you are going to be using ArcGIS Pro as Personal Geodatabases can't be read/used in ArcGIS Pro

To answer your question-

what do you see in GDB_Items?

Re: Personal GDBs: How are feature classes and feature datasets linked?

AlfredBaldenweck — Tue, 08 Aug 2023 13:52:55 GMT

No worries, I am well aware that Pro doesn't do personal geodatabases and am in the process of converting what we have.

More to the point:

I don't have a GDB_Items table.

The only thing that lists all of them (feature classes, feature dataset) is GDB_UserMetadata

This is an .mdb, and ArcMap/Catalog correctly shows them as being inside the feature dataset.

I just opened up another, entirely unrelated MDB and have the same experience.

Why wouldn't they just be linked in a field in the feature class table, like, for example, Spatial reference is?

I'm very confused, here.

Edit: Apparently it's because these MDBs are from an earlier version. Once upgraded to 10, the items table appears. However, without upgrading them, how can it tell what they belong to?

Re: Personal GDBs: How are feature classes and feature datasets linked?

AlfredBaldenweck — Tue, 08 Aug 2023 14:03:19 GMT

Okay. According to ArcGIS Server for the Java Platform 9.3 Help (esri.com), the feature datasets are linked to feature classes via the GDB_ObjectClasses table.

So, in my test database:

Not sure how far back feature datasets were introduced, but for version 10+, use GDB_Items and for 9 (and maybe earlier) use GDB_ObjectClasses.

Will update this post if I find anything for earlier versions.