Feature Datasets and Spatial Reference

Like most things on my GIS blog, this serves to remind me of something. I'm a little late getting on board with the Geodatabase but more and more I'm adopting it for everything that I do (especially when working with ArcGIS 10.1). Not only have I finally started using the File Geodatabase but I recently started having output put into different Feature Datasets within the Geodatabase.

One thing that I need to remember is that you can't name two feature classes in two different feature dataset with the same name. It would be convenient if you could but it will scream at you that “it already exists”. You can argue that it does not but in the mind of ArcGIS ... it does.

The other thing to remember is that the feature dataset has its own projection. I spent five minutes trying to define the projection for a batch of feature classes with a Python script that defines projection in batch mode (yes I know there is a tool in the toolbox now for that but I wanted to use my script). It doesn't work.

But that is ok that it doesn't work because you can simply define the feature dataset and all the feature classes inside it are magically defined (and magically delicious). Hopefully I will never again spend five minutes (or two minutes) wondering about this phenomenon.