One of the standards I recommend in my book Check List for Doing Data Model Design Reviews is to use color in your diagrams to visually differentiate types of entities or tables.
As luck would have it, Oracle SQL Developer Data Modeler has a feature that makes this very easy. It is Classification Types.
In the latest version. 4.0, you set these up by going to the context menu on the Design level. From that menu pick Properties. Once on the property dialog go to Settings -> Diagram -> Classification Types. (In 3.x look under Tools -> Preferences)
The default install comes with a bunch already – fact, dimensions, logging, summary, and temporary. Each has a pre-set color assigned. You can change that color by clicking on the color and selecting another option from the pallet. You can also set a prefix for each type. (Note – if you are already using a classification and change the color, when you hit apply the new color will be applied in all existing diagrams within the design.)
You add new types by clicking the green plus (+) sign and then just add in whatever you want and save.
For Data Vault modeling, I add three new types: Hub, Link, and Satellite with the colors you see in the screen shot here.
To apply a classification type to an existing table, open the table property dialog and look for the classification types node in the tree (in 4.0). In 3.x, there is a simple classification type drop down on the main property page.
Once applied, the first letter of the classification type will appear in the upper left corner of the table (see screen shot).
Another way I have used this recently was in my current data warehouse project where I have source, stage, and dimensional tables all in one design. I found I often want to show all three tiers in on diagram (sub view) for a sprint (we are using a SCRUM approach) to help the ETL programmers and QA folks have one place to go where they can see how these layers are related. So for this project, I also added a source and stage classification type.
So if you have been color coding you diagrams by hand, this tip should save you a bunch of time since you won’t have to pick the colors by hand on each table. Plus the color selection will be more consistent.
If you aren’t color coding, now would be a great time to start!
Bonus Tip: If, like me, you want to be consistent across all your designs with the types and colors, I just figured out I can hack the dl_settings.xml file to copy my classification type customizations from one design to another. Just be sure to exit and then restart SDDM after you update the file for it to take effect.
Have fun coloring your diagram! (Maybe more people will read them)
The Oracle Data Warrior