View Source Ash.Resource.Identity (ash v2.5.16)
Represents a unique constraint on a resource
Data layers should (and all built in ones do), discount
null (in the case of postgres) values
when determining if a unique constraint matches. This often means that you should
prefer to use identities with non-nullable columns.
Eventually, features could be added to support including
null values, but they would
need to include a corresponding feature for data layers.