Domain

I see quite a bit of requests around Domains, but I am unsure if my requirement is covered in them, as many of them relate to Class modelling.

In my experience with tools such as Erwin, you have the ability to define a Domain, which is not really a custom / user defined datatype, but rather a user defined pattern, or implementation of a data type.

So for example, if I decide that all attributes of "Primary Key" database, would have the following characteristics:

• a primary key, 
• not null, 
• auto generated 
• integer data type

Another example, I could model a "description data type", which would be:

• nullable
• nvarchar(255)

Etc. When designing large, complex data models, this has quite a large impact on productivity, especially if one has to apply a change to a large model.